mk 5 golf R32 - misfire
Discussion
Not good news, I’m absolutely gutted and feel sick. Dan has completed a compression test and no 1 cylinder is down to about 25psi, the others are about 20% down on what they should be, hence the blue smoke. He has put a camera down and the top of the piston on No1 is damaged, so there are two options:
1. Strip head off, new pistons and check / hope there is no damage to the bores. £2k (excluding bores)
2. Find a new engine with similar mileage and replace £1.5k to £2k plus labour to fit and remap again.
The cause – Dan said it was the tesco momentum fuel, it is fine for standard engines, but the engines ability to adjust to the impurities of the fuel is less on a car running 100 bhp more. Apparently its happened before with 1 other customer about 5 years ago. I'm still astounded that fuel could do this, but it does tie in with my experience because the car was running fine until filling up with Tesco. My preference is to go with option 1, as can you really trust the longevity of an unknown second hand engine?
Due to the TRD workload, it could be 2-3 weeks before they can even give my car sole attention, but I’ve asked them to start on stripping the head which they will try to do in between jobs. I’m now without a car, reliant on work allowing me use of the pool car or getting lifts to and from work, let alone the cost. Just cannot believe it. Wish I’d never sold the GTI now.
1. Strip head off, new pistons and check / hope there is no damage to the bores. £2k (excluding bores)
2. Find a new engine with similar mileage and replace £1.5k to £2k plus labour to fit and remap again.
The cause – Dan said it was the tesco momentum fuel, it is fine for standard engines, but the engines ability to adjust to the impurities of the fuel is less on a car running 100 bhp more. Apparently its happened before with 1 other customer about 5 years ago. I'm still astounded that fuel could do this, but it does tie in with my experience because the car was running fine until filling up with Tesco. My preference is to go with option 1, as can you really trust the longevity of an unknown second hand engine?
Due to the TRD workload, it could be 2-3 weeks before they can even give my car sole attention, but I’ve asked them to start on stripping the head which they will try to do in between jobs. I’m now without a car, reliant on work allowing me use of the pool car or getting lifts to and from work, let alone the cost. Just cannot believe it. Wish I’d never sold the GTI now.
Awww man, gutted for you 
I suspected a knackered piston after you said the misfire on 1 cylinder persisted after a new coil.
Just prior to the engine dropping in power, were you driving it quite hard, or just cruising?
In my experience of boosting VR6 engines, I'm leaning more towards boost related detonation damage than fuel quality.
Is he implying injector 1 got clogged from impurities in the fuel? The fuel filter traps anything the injector can't flow through it's pintles, so I'm not buying that. It's that age old can of worms thing with aftermarket tuning, isn't it. They can't prove to you naff fuel caused the damage, and you can't prove to them boost related pinking caused it. A sticky situation. Was there a warranty for this work originally?
The only way I can see fuel being the root cause is if it was mislabelled at the pumps, or they put the wrong stuff in the underground tanks, meaning you picked up 95 and not 99. Your ECU will have been mapped for Super Unleaded I expect. I've seen other tuners (funnily enough) blaming V Power for customers cars not making the claimed power. Seems to be a growing trend.
Personally I would stick with it and get a decompression plate fitted this time, but not too thick as they can mess with the cam timing.
Second hand BUB engines are generally fine in my experience and I would take that option personally. I tend to lose faith in detonation damaged engines.
Hope it works out for you, keep us posted!
I suspected a knackered piston after you said the misfire on 1 cylinder persisted after a new coil.
Just prior to the engine dropping in power, were you driving it quite hard, or just cruising?
In my experience of boosting VR6 engines, I'm leaning more towards boost related detonation damage than fuel quality.
Is he implying injector 1 got clogged from impurities in the fuel? The fuel filter traps anything the injector can't flow through it's pintles, so I'm not buying that. It's that age old can of worms thing with aftermarket tuning, isn't it. They can't prove to you naff fuel caused the damage, and you can't prove to them boost related pinking caused it. A sticky situation. Was there a warranty for this work originally?
The only way I can see fuel being the root cause is if it was mislabelled at the pumps, or they put the wrong stuff in the underground tanks, meaning you picked up 95 and not 99. Your ECU will have been mapped for Super Unleaded I expect. I've seen other tuners (funnily enough) blaming V Power for customers cars not making the claimed power. Seems to be a growing trend.
Personally I would stick with it and get a decompression plate fitted this time, but not too thick as they can mess with the cam timing.
Second hand BUB engines are generally fine in my experience and I would take that option personally. I tend to lose faith in detonation damaged engines.
Hope it works out for you, keep us posted!
Admittedly I'm not particularly familiar with the Bosch ecu the R32 uses, but I'd have expected it to detect knock and pull timing to prevent this?! Or is it a downside of supercharging an engine that has an ecu designed for NA applications? I.e. it couldn't pull enough timing to prevent detonation...
I'd agree that blaming the fuel, on the basis of its brand, is a cop out too. Did he elaborate on why the other cylinders might be down on compression? So they have holed pistons too?
It does sound like dramatic leaning out on that particular cylinder with generally poor mapping causing the other issues.
Paul
I'd agree that blaming the fuel, on the basis of its brand, is a cop out too. Did he elaborate on why the other cylinders might be down on compression? So they have holed pistons too?
It does sound like dramatic leaning out on that particular cylinder with generally poor mapping causing the other issues.
Paul
Edited by KryptonKid09 on Thursday 14th January 15:09
KryptonKid09 said:
Admittedly I'm not particularly familiar with the Bosch ecu the R32 uses, but I'd have expected it to detect knock and pull timing to prevent this?! Or is it a downside of supercharging an engine that has an ecu designed for NA applications? I.e. it couldn't pull enough timing to prevent detonation...
I'd agree that blaming the fuel, on the basis of its brand, is a cop out too. Did he elaborate on why the other cylinders might be down on compression? So they have holed pistons too?
It does sound like dramatic leaning out on that particular cylinder with generally poor mapping causing the other issues.
Paul
Without seeing the modified map to confirm, it's possible the ECU ran out of timing retard. From memory, I think the R32's ECU has a maximum retard of 12 degrees. Pure speculation here, but if insufficient advance was pulled from the base map, it doesn't give the engine a lot of headroom. I'd agree that blaming the fuel, on the basis of its brand, is a cop out too. Did he elaborate on why the other cylinders might be down on compression? So they have holed pistons too?
It does sound like dramatic leaning out on that particular cylinder with generally poor mapping causing the other issues.
Paul
Edited by KryptonKid09 on Thursday 14th January 15:09
Cylinder 1 probably let go first because that and number 6 run the hottest on this engine, having the smallest coolant jackets. As for the others dropping 20%, I can't really see that happening personally. They were probably that low to begin with. The blue smoke will be from the hole in piston 1, or it's probably chewed up on the edge of the crown and the piston rings snapped. If so, the bore is likely scored, so it would be better to start over with a new engine.
The only question mark is it running fine just prior to putting the Tesco fuel in. We'll know more once the head is lifted I guess.
KryptonKid09 said:
SuperchargedVR6 said:
If so, the bore is likely scored, so it would be better to start over with a new engine.
Or take that block out to 3600cc... 
Agreed though, the investigation should be an interesting one.
Paul
Loads more stroke and bore, and has a 10.5 degree vee instead of 15. That 3.6 is pretty weak when it comes to boost though. The old 12V war horse is by far the strongest VR6 engine for boost.Yeah, I need to get out more!
No it wasn't being driven hard, filled up with the fuel (now known as the fuel of doom) last Thursday evening, drove it to work the next day, no problem, on the Saturday I had been out for about 90 mins, pulled over for a coffee for about an hour, got back in to drive, started fine, sounded fine, after 200 meters, I went to pull away normally (still in town centre so low speeds) and it was down on power and running rough.
Not heard of a decompression plate before, in layman's terms, whats its purpose? I had a few questions for TRD, to save me retyping these, they are (below) for reference. TRD have been very helpful.
1. Ben mentioned there was a 12 month warranty on the supercharger conversion, what does this cover?
2. What checks were carried out to the engine to ensure it was healthy to proceed with the supercharger work?
3. Given there is a fuel filter, why wouldn't this protect the engine from any impurities present in Tesco Super unleaded fuel? Surely Tesco Super has to meet certain requirements to be sold to the public? The engine was mapped for super-unleaded, so I don't understand how this could be the cause of piston ring failure.
Given the situation I'm faced with, and considering costs, would you replace with a second hand engine, or go down the route of replacing pistons etc?
RESPONSE
the 12month warranty covers the supercharger itself, the supercharger drive system and pulleys excluding rubber belts, boost hoses and clips, the main mountings against cracks and the diverter valve.
Before we consider a conversion, the mileage, service history and previous tuning work (if any) is taken into account. When the car arrives we perform a road test, diagnostic check, a chain tolerance check on Vag-Com to make sure there is no excess stretch, a cylinder compression check and finally a visual inspection. If anything is required the customer is notified before the work is carried out.
A fuel filter is there to catch any larger debris that could clog the injectors. It will not protect the fuel pump nor will it stop any fluid impurities like water or silicone.
The fuel meets certain basic standards but at the end of the day it’s a discounted fuel. You can buy supermarket engine oil but would you put it in your car? Supermarkets also sell budget alcohol and food but you do not have to chose to buy them as most of it is crap.
When you are tuning a car to high power you should always buy the best you can afford. You can buy budget brake pads for the R32 but if you install them into a high power car, the chances are you wouldn’t be able to stop well if at all!
If your car was completely standard, you could run it on any fuel of your choice and it would probably be fine but run worse on the cheaper brands. Once you modify it, it’s a whole different story. On your R32, there is a red sticker in the petrol flap that clearly states SHELL V-POWER only, it’s not a suggestion, it’s an instruction.
Unfortunately you have had to find out the hard way that choosing a budget brand has not ended up with good results.
Choosing a second hand engine is always a gamble as you never know its history. I am hoping that your engine is in salvageable condition (due to its previous good maintenance) and that the bores are not damaged.
We will begin to strip the engine so we can get a clear picture of the pistons/bores. END.
Yes ok, so I did see the V Power sticker on the fuel filler cap, but figured any super unleaded would be ok, after all, you are not always going to be in a location to fill up with Shell. Chain was checked for tolerance and any work needed before the conversion was passed on to the previous owner. Really hope the bores are ok.
Not heard of a decompression plate before, in layman's terms, whats its purpose? I had a few questions for TRD, to save me retyping these, they are (below) for reference. TRD have been very helpful.
1. Ben mentioned there was a 12 month warranty on the supercharger conversion, what does this cover?
2. What checks were carried out to the engine to ensure it was healthy to proceed with the supercharger work?
3. Given there is a fuel filter, why wouldn't this protect the engine from any impurities present in Tesco Super unleaded fuel? Surely Tesco Super has to meet certain requirements to be sold to the public? The engine was mapped for super-unleaded, so I don't understand how this could be the cause of piston ring failure.
Given the situation I'm faced with, and considering costs, would you replace with a second hand engine, or go down the route of replacing pistons etc?
RESPONSE
the 12month warranty covers the supercharger itself, the supercharger drive system and pulleys excluding rubber belts, boost hoses and clips, the main mountings against cracks and the diverter valve.
Before we consider a conversion, the mileage, service history and previous tuning work (if any) is taken into account. When the car arrives we perform a road test, diagnostic check, a chain tolerance check on Vag-Com to make sure there is no excess stretch, a cylinder compression check and finally a visual inspection. If anything is required the customer is notified before the work is carried out.
A fuel filter is there to catch any larger debris that could clog the injectors. It will not protect the fuel pump nor will it stop any fluid impurities like water or silicone.
The fuel meets certain basic standards but at the end of the day it’s a discounted fuel. You can buy supermarket engine oil but would you put it in your car? Supermarkets also sell budget alcohol and food but you do not have to chose to buy them as most of it is crap.
When you are tuning a car to high power you should always buy the best you can afford. You can buy budget brake pads for the R32 but if you install them into a high power car, the chances are you wouldn’t be able to stop well if at all!
If your car was completely standard, you could run it on any fuel of your choice and it would probably be fine but run worse on the cheaper brands. Once you modify it, it’s a whole different story. On your R32, there is a red sticker in the petrol flap that clearly states SHELL V-POWER only, it’s not a suggestion, it’s an instruction.
Unfortunately you have had to find out the hard way that choosing a budget brand has not ended up with good results.
Choosing a second hand engine is always a gamble as you never know its history. I am hoping that your engine is in salvageable condition (due to its previous good maintenance) and that the bores are not damaged.
We will begin to strip the engine so we can get a clear picture of the pistons/bores. END.
Yes ok, so I did see the V Power sticker on the fuel filler cap, but figured any super unleaded would be ok, after all, you are not always going to be in a location to fill up with Shell. Chain was checked for tolerance and any work needed before the conversion was passed on to the previous owner. Really hope the bores are ok.
I still don't see how a little bit of water would put a hole in a piston but silicone will totally screw the lambda probes, but since there are no fault codes, we can out-rule that.
Never mind. The Tesco fuel has been drained off, so it's too late to send it off for lab analysis. Shame really because you are now faced with a 4 figure bill (potentially), and if Tesco sold you crap, they could have been liable to some extent.
I only ever use V Power. It's by far the most consistent fuel I've ever used. Funnily enough, the only time I've had running problems with my old R32s was when it was run on Tesco Momentum, but it was intermittent, and it didn't wreck a piston.
A decompression plate (aka 'head spacer') is a steel plate which reduces the compression ratio from 10.75:1 to around 9:1, depending on the thickness. It's a copy of a head gasket basically. Reduced compression makes it safer for boost. The OEM cast pistons aren't that strong when things go wrong unfortunately. Forged pistons are a lot stronger but they're not cheap.
Never mind. The Tesco fuel has been drained off, so it's too late to send it off for lab analysis. Shame really because you are now faced with a 4 figure bill (potentially), and if Tesco sold you crap, they could have been liable to some extent.
I only ever use V Power. It's by far the most consistent fuel I've ever used. Funnily enough, the only time I've had running problems with my old R32s was when it was run on Tesco Momentum, but it was intermittent, and it didn't wreck a piston.
A decompression plate (aka 'head spacer') is a steel plate which reduces the compression ratio from 10.75:1 to around 9:1, depending on the thickness. It's a copy of a head gasket basically. Reduced compression makes it safer for boost. The OEM cast pistons aren't that strong when things go wrong unfortunately. Forged pistons are a lot stronger but they're not cheap.
It's Ben here, the former owner. I checked the web to see how things were going after Si texted me recently... and oh my Giddy-od!! I haven't been on any car forums at all since going cold turkey / selling the R32.
I feel sick reading this - although can reassure Si that I only used V-Power in the time that the car was mine (even on a road trip to France).
I suggest keeping things sweet with TRD - they are very knowledgeable and my experience suggests they'd be helpful.
I feel sick reading this - although can reassure Si that I only used V-Power in the time that the car was mine (even on a road trip to France).
I suggest keeping things sweet with TRD - they are very knowledgeable and my experience suggests they'd be helpful.
Hi Ben, I'm still getting over the shock of what's happened, but feel better knowing the car is with a safe pair of hands. It was running perfectly for the last 6 weeks since I bought it from you and I've covered around 2000 miles in that time. I will just have to wait and see what happens once TRD have the head off. I shall probably make the journey over to see them in any case to see firsthand what's happened and also to meet Dan, I know they have a good reputation for these conversions. I just find it difficult to accept how different brands of super unleaded can result in this. TRD have said because the engine is modified, the tolerances in terms of knock sensors and other bits in the hardware/software are far reduced to run on different fuels. It's happened to only one other stage 1 charger conversion car, where poor fuel was put in. Anyway, I am where I am.
Hope you are well and enjoying the new family wagon.
Hope you are well and enjoying the new family wagon.
si_xsi said:
The fuel meets certain basic standards but at the end of the day it’s a discounted fuel.
I fail to see what relevance that has to the fuel's quality. The only reason it's discounted is because it's not the primary product and they buy it in bulk. It would cost them more money to make 'inferior' fuel as they'd have to refine it differently from the rest of the stock.Sorry OP but this boils my bacon as they're either assuming you're an idiot or they don't have a clue what their talking about and actually believe this drivel.
I ran my Pulsar GTiR at 90bhp and 0.4bar of boost over stock with no mapping changes for 5k miles or so on Tesco 99 without issue. They're known to have weak pistons.
I also ran my Evo at 1.8bar of boost (stock is 1.1bar) and circa 90bhp over stock (mapped for V-Power) for an extended period of time without issue. As mentioned, both engines 'preferred' V-Power, feeling smoother and being more economical, so I went back to using that (an some methanol on the Evo but that's another conversation).
This smacks of a mapping issue and from what you written, one that manifested over a period of time. You don't get det driving the car the way you've described. That said, it also highlights what a fine line you walk with the R32 when you add a blower. The ecu just can't provide the safety net required to prevent this happening.
Best of luck with getting this sorted.
Paul
KryptonKid09 said:
This smacks of a mapping issue and from what you written, one that manifested over a period of time. You don't get det driving the car the way you've described. That said, it also highlights what a fine line you walk with the R32 when you add a blower. The ecu just can't provide the safety net required to prevent this happening.
That fine line turns to a much thicker one with a spacer plate and an intercooler SuperchargedVR6 said:
That fine line turns to a much thicker one with a spacer plate and an intercooler
Agreed, at the same boost levels, they will reduce the chances of det. I think you'll agree though that typically, if you fit a spacer plate and intercooler, you do it to facilitate an increase in boost levels (that's what I'd do). So thicker line becomes fine again. 
I also think you'll agree that the safety net remains the same size regardless as it just seems the ECU can't cope in the same way that a good ECU designed for an FI car would, if put in a sticky situation. Again I'm speculating from the evidence as I'm not intimately familiar with the ME7.1.1 ECU.
On a related note, the OP would be better off doing it properly now and fitting low compression (forged) pistons, wouldn't he?
That aside, if it were me, I'd get it put back together and taken to Vince @ Stealth Racing to map.
Paul
KryptonKid09 said:
SuperchargedVR6 said:
That fine line turns to a much thicker one with a spacer plate and an intercooler
Agreed, at the same boost levels, they will reduce the chances of det. I think you'll agree though that typically, if you fit a spacer plate and intercooler, you do it to facilitate an increase in boost levels (that's what I'd do). So thicker line becomes fine again. I also think you'll agree that the safety net remains the same size regardless as it just seems the ECU can't cope in the same way that a good ECU designed for an FI car would, if put in a sticky situation. Again I'm speculating from the evidence as I'm not intimately familiar with the ME7.1.1 ECU.
On a related note, the OP would be better off doing it properly now and fitting low compression (forged) pistons, wouldn't he?
That aside, if it were me, I'd get it put back together and taken to Vince @ Stealth Racing to map.
Paul
The only downside there is you need to spin the charger faster to get the desired 6-7psi at the throttle because, as you know being boost experienced, intercoolers rob a bit of pressure. Turbos are easy as they just keep spinning until the target boost is met
Forged pistons would definitely be a good move whilst it's in pieces. A nice set of 8.5:1 Wossners come in at £750ish last time I looked. They're strong and aren't sloppy in the bores like some aftermarket pistons. I used them in my old VR6 turbo for 60K trouble free miles before parting with the car.
Spacers work and are cheap, but some of them are too thick and cause cam alignment fault codes. Some tuners add a link to the chain to get round that but it's a messy Band-Aid fix imo.
The safety net can be increased if the standard timing map is retarded in the boost regions, rather than leaving it and relying on the knock control to sort the mess out, but again, we're just speculating having not seen the map
The R32 has a very good combustion chamber and doesn't run a lot of timing compared to say, the 12V VR6, which has a rubbish combustion chamber!Another factor on the R32 is the variable cam timing and intake geometry. Both of these plump up the torque curve quite nicely and with boost on top, the ignition timing becomes even more of an issue.
Yeah Vince is the Daddy with the boosted VR6/R32 engines. I don't think TRD would be too happy about another tuner having a look at the map though, so it would have to be done again from scratch.
Sorry to hear of your issue OP - horrible situation.
The problem I have with TRD's claim is that they seem to be saying that they recommend V-Power on the basis of it being more reliable than Momentum i.e. it's more unlikely for V-Power to be contaminated than Momentum and that, in actual fact, Momentum will run perfectly well, provided it isn't contaminated. After all, as I understand it, Momentum and V-Power are chemically very similar - with the only differences being the mix of oxygenates the fuels use - nothing however to make one suitable and one not suitable for boosted cars.
I don't believe for a second that it's a fuel related issue and, from the information you provided, think that it's much more likely to be the result of a knocking issue the car has/had which has eventually caused the failure.
The problem I have with TRD's claim is that they seem to be saying that they recommend V-Power on the basis of it being more reliable than Momentum i.e. it's more unlikely for V-Power to be contaminated than Momentum and that, in actual fact, Momentum will run perfectly well, provided it isn't contaminated. After all, as I understand it, Momentum and V-Power are chemically very similar - with the only differences being the mix of oxygenates the fuels use - nothing however to make one suitable and one not suitable for boosted cars.
I don't believe for a second that it's a fuel related issue and, from the information you provided, think that it's much more likely to be the result of a knocking issue the car has/had which has eventually caused the failure.
Edited by MrBarry123 on Tuesday 19th January 17:35
Thanks Krypton and Supercharged - some interesting extra things here, which to a person who Is new to modified cars, is invaluable. So it would seem I need to:
1. Establish who mapped the car after the work. Where is Vince 'the map daddy' located?
2. Consider forged pistons as a minimum
3. Consider a spacer plate, although this could bring problems with cam chain stretch - are they expensive? Will also reduce boost and some BHP, but ultimately safer
4. Consider intercooler - how much approx?
I wonder whether the car has been mapped to obtain as much BHP as possible without regard for the stage 1 supercharger components, or were the pistons already in a poor state before the conversion. Both speculative, and nothing I can do about it now, but for someone who bought (perhaps rather naively now) this to be a daily driver, I do not want to get the car back with whatever work being done, to live in fear of it breaking again, and costing thousands more.
I have a holiday to the South of France in June and wanted to take the R32. But if I cannot use or trust the car because of high intake temps, long driving hours at 80mph, and limited shell garages etc etc, what's the point. What's the point of even having such a car if its so fragile.. A standard R32 was built for this type of long distance trip.
1. Establish who mapped the car after the work. Where is Vince 'the map daddy' located?
2. Consider forged pistons as a minimum
3. Consider a spacer plate, although this could bring problems with cam chain stretch - are they expensive? Will also reduce boost and some BHP, but ultimately safer
4. Consider intercooler - how much approx?
I wonder whether the car has been mapped to obtain as much BHP as possible without regard for the stage 1 supercharger components, or were the pistons already in a poor state before the conversion. Both speculative, and nothing I can do about it now, but for someone who bought (perhaps rather naively now) this to be a daily driver, I do not want to get the car back with whatever work being done, to live in fear of it breaking again, and costing thousands more.
I have a holiday to the South of France in June and wanted to take the R32. But if I cannot use or trust the car because of high intake temps, long driving hours at 80mph, and limited shell garages etc etc, what's the point. What's the point of even having such a car if its so fragile.. A standard R32 was built for this type of long distance trip.
You said said:
I wonder whether the car has been mapped to obtain as much BHP as possible without regard for the stage 1 supercharger components, or were the pistons already in a poor state before the conversion. Both speculative, and nothing I can do about it now, but for someone who bought (perhaps rather naively now) this to be a daily driver, I do not want to get the car back with whatever work being done, to live in fear of it breaking again, and costing thousands more.
Nail on head.There's absolutely no reason why you can't run a supercharged R32 as a daily driver and it be reliable however I would at the very least expect it to need forged internals.
Don't miss out on that trip to France in it if you can help it!
si_xsi said:
Thanks Krypton and Supercharged - some interesting extra things here, which to a person who Is new to modified cars, is invaluable. So it would seem I need to:
1. Establish who mapped the car after the work. Where is Vince 'the map daddy' located?
2. Consider forged pistons as a minimum
3. Consider a spacer plate, although this could bring problems with cam chain stretch - are they expensive? Will also reduce boost and some BHP, but ultimately safer
4. Consider intercooler - how much approx?
I wonder whether the car has been mapped to obtain as much BHP as possible without regard for the stage 1 supercharger components, or were the pistons already in a poor state before the conversion. Both speculative, and nothing I can do about it now, but for someone who bought (perhaps rather naively now) this to be a daily driver, I do not want to get the car back with whatever work being done, to live in fear of it breaking again, and costing thousands more.
I have a holiday to the South of France in June and wanted to take the R32. But if I cannot use or trust the car because of high intake temps, long driving hours at 80mph, and limited shell garages etc etc, what's the point. What's the point of even having such a car if its so fragile.. A standard R32 was built for this type of long distance trip.
1. Vince heads up Stealth Racing in Southam, Warwickshire. http://stealthracing.co.uk Their website is ancient but it's well worth having a chat with Vince regarding the mapping.1. Establish who mapped the car after the work. Where is Vince 'the map daddy' located?
2. Consider forged pistons as a minimum
3. Consider a spacer plate, although this could bring problems with cam chain stretch - are they expensive? Will also reduce boost and some BHP, but ultimately safer
4. Consider intercooler - how much approx?
I wonder whether the car has been mapped to obtain as much BHP as possible without regard for the stage 1 supercharger components, or were the pistons already in a poor state before the conversion. Both speculative, and nothing I can do about it now, but for someone who bought (perhaps rather naively now) this to be a daily driver, I do not want to get the car back with whatever work being done, to live in fear of it breaking again, and costing thousands more.
I have a holiday to the South of France in June and wanted to take the R32. But if I cannot use or trust the car because of high intake temps, long driving hours at 80mph, and limited shell garages etc etc, what's the point. What's the point of even having such a car if its so fragile.. A standard R32 was built for this type of long distance trip.
2. If you opt for forged pistons, I would opt for standard size 'drop-in' ones if the bores are OK. That way the factory honing is retained and therefore oil consumption shouldn't change, which is negligible on R32s.
I just had a quick look and these are 8.0:1, which is quite a drop in compression. Engine braking may suffer as a result - http://forged-pistons.co.uk/webshop/wossner-automo...
Have a chat with Jon at Stealth Racing as he's built several R32 turbos and may suggest some other options.
3. Only if they're too thick. There is a brand I can't remember off hand which drops compression to around 9:1 which isn't too thick but again, Jon can advise on that. With your low boost levels, this would be the most cost effective solution.
4. Again, Jon may know as I'm not sure what intercoolers will fit a MK5 R32 in a discrete manner. If you go down this route, you will need a smaller pulley for the supercharger as discussed, but this is something TRD will need to arrange for you.
Between TRD and the boys at Stealth Racing, I'm confident a decent and dependable package can be specced up for you.
It's truly hard to say after the fact. Some tuners tune aggressively, some a bit safer. Vince is in the latter camp. If it were my engine, I would ask for it to be mapped for 95 unleaded. Peak hp is one thing, reliability is another. Standard R32s can run on 95, and so should supercharged ones be able to if it's mapped accordingly.
A boosted R32 would make an awesome touring car and I don't see why its not possible. I took my Corrado VR6 turbo on several road trips and it felt unburstable. That had forged pistons and ran on 95 or 99 unleaded no probs. I mapped that one myself
SuperchargedVR6 said:
If it were my engine, I would ask for it to be mapped for 95 unleaded. Peak hp is one thing, reliability is another. Standard R32s can run on 95, and so should supercharged ones be able to if it's mapped accordingly.
This is an excellent point and suggestion and would, in one swoop, solve you're worries about reliability.Personally, I go the other way with my tuning and get the mapping set up to be as aggressive as possible. A case in point was my Evo. Typically owners would tune the Evo VII to 1.6bar of boost as it was deemed safe. After extensive research I had mine mapped to run 1.8bar on V-Power. I ran it like that for several years and 10's of thousands of miles with no issues at all.
The reason I go this route is that I have mechanical sympathy without fail. I'll warm the car up so oil temps are above 70 degrees C before I use more than 3k rpm (and ANY boost on the Evo). I always use the best oils possible and change them on or before the typical schedule calls for it.
If I have to use lower octane fuel, I'll drive the car accordingly until I'm confident the contents of the fuel tank is at the octane level the car is tuned for. That may take 2 or 3 fills but it's a road car and it's not difficult to drive sensibly for 1k miles or so. You can of course speed things up with a good octane booster or methanol...
That aside, I suspect you'd be happy going with SuperchargedVR6's suggestion.
At the stage you're at now, if it were my car, I'd consult Stealth and state your preferred route is to use forged pistons (of the drop in variety pending bore analysis). The spacer plate has always felt like a bodge to me. It obviously works as it's used the world over, it just doesn't fit my principles when another tried and tested method with no possible disadvantages is available.
Having read reviews of the TRD conversion previously that had dyno stats that included intake temperature readings across runs, I'd also fit an intercooler. This will be expensive as it involves plumbing (pipe work), the core itself and modifying the bumper. Along with the pulley and mapping changes required. However, not only would that result in the intake temperatures being much more consistent and ultimately lower overall, it would also mean you could get a bit more safe power/torque too.
I will make it clear that I've not gone N/A to FI before so I would advise you put a greater weighting on the advice of someone who has (a few times), like SuperchargedVR6. I have tuned both types of set up though (mostly FI infact) so have an understanding of the basics at least.
Good luck with whatever you decide and please keep us posted.
Paul
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