SC Power conversions

[Belle427]

Boosted LS1 said:

It is sensible to start with a good engine and so long as it's not worn it should be fine. Turbo boost won't cause an increase in mechanical risk unless you over rev. Boost is more about heat management and especially about detonation avoidance. If your engine's a 3.5 or a 3.9 then a switch to a later engine would be a benefit but only because the designs better and the pistons are stronger.

I'd compression test your engine and see if the readings are healthy.

I would hope a 79k mile engine would show very little signs of wear on the bottom end, especially if it's been well serviced with modern lubricants.
I know the cam could be a weak link but again if the engine sounds healthy and has good compression readings is there really much else you can do?

[coco79]

PhilH42 said:

You will have to excuse the wind noise...I'm sure there are some more talented uploaders than me who could get rid of much if it with other software and playing around with frequencies, but I'll have to shield the microphone better in future. Might (or might not) give you a feel for the sound on acceleration so you can decide if its too quiet for you...its only on a standard exhaust at the moment.

I'm going to try and get something better as Chimaera Turbo's are not that well represented on youtube although a couple of guys have posted some good stuff recently.

Also worth noting is mine is modest power and torque compared to some on here.

https://youtu.be/J6bMmzS0Lwg

Edited by PhilH42 on Tuesday 5th September 19:03

Phil, that sounds much better! I think some of the other clips out there make the turbo sound rather underwhelming!

Edited by coco79 on Wednesday 6th September 13:05

[Steve_D]

Belle427 said:

...........I know the cam could be a weak link but again if the engine sounds healthy and has good compression readings is there really much else you can do?

The hydraulic lifters do a very good job of hiding a worn cam. It can still be quiet and will not show up on a compression test.

Steve

[macdeb]

DonkeyApple said:

people rarely post about what's gone wrong with their FI route.

I blew a turbo seal twice, first one was bad luck as it was faulty from new. Otherwise no prob's though I did purpose build it for FI. Only problem now is that I'm now really regretting selling it

[QBee]

macdeb said:

DonkeyApple said:

people rarely post about what's gone wrong with their FI route.

I blew a turbo seal twice, first one was bad luck as it was faulty from new. Otherwise no prob's though I did purpose build it for FI. Only problem now is that I'm now really regretting selling it

I have no issues at all with the turbo's operation (early days), nor with the transmission, but I avoided going too mad on the boost front.
My only issue to date has been with excess heat on a track day - I need to revisit my cooling system, but only for track days where the turbo is at max boost for so much of the time.

I am presently researching the viability of actually removing one, if not both, cooling fans for track days.
It will mean taking the radiator out once only, and modifying the bottom fan mounting to a sliding hook.
Then on the morning of a track day i can just undo a couple of captive-nutted bolts at the top, unclip the electrical connector, and slide the fan off the bottom hook type connector to remove it/them.

Sounds counter-intuitive, until you realise that you want the engine up to temperature, not cold, so a couple of minutes queueing in the pitlane won't harm it, and the 80-140 mph wind going through the radiator on track is a darn sight faster-moving than the air drawn in by the fans. The fans are only really there for sitting in queueing traffic, which is not something you normally suffer at Oulton Park or Snetterton. Fans actually block the passage of wind through the radiator.

What made me think of this solution is something that Mat Smith said to me. He has a problem with his race engine. He has no fans, as he doesn't need them on a race car, and his biggest problem is actually getting the engine to stay at proper operating temperature on track. It tends to run too cool (bit like my TVR on a December blat down the M1 - 65 on the temperature gauge and my toes are frozen), thanks to the efficiency of the standard TVR radiator.

[TV8]

Hi Anthony, I might be imagining what I am about to type but I have a recollection that sealing the gap between the car and the radiator can improve cooling by forcing the air through the rad rather than escaping around the edges as well.

That is assuming yours isn't already sealed!

[QBee]

You are right - I will check my car for that gap.

[AceOfHearts]

Have another from when the clutch was slipping heavily, but the mic was in the engine bay so you can really hear the turbo spool up

I should have got some better videos in the nice weather really :/

https://youtu.be/mJqZbfyznrw

[ITVRI]

Aceofhearts. I think I remember reading that you undertook your turbo conversion on a high mileage engine. Any problems with it so far?

[Boosted LS1]

A crank driven viscous fan an is a fab solution :-). It sorted out my low speed woes. You'll need to make your own nose cone adaptor to get the blades up close to the radiator.

[AceOfHearts]

ITVRI said:

Aceofhearts. I think I remember reading that you undertook your turbo conversion on a high mileage engine. Any problems with it so far?

Its been in a year now and the standard engine is holding up absolutely fine (including 2 drag days!)

It is currently on 118,000 miles and has never been opened, and as far as i can tell is still on the original cam!

Running 10psi boost with no complaint and still uses no oil. I was kind of hoping to blow it up as an excuse to build a nice forged 4.5 for it but no luck yet

[QBee]

Re my apparently hot engine on track days, I do need to do two mods (one of which is sitting on my desk right now) to my car before looking at removing fans for track days.

First mod is to install the little resistor and cable I bought to the Range Rover water temperature sender, therefore bypassing the TVR one, and calibrate the gauge from my computer via the Emerald software. I bought the mod a few weeks ago and haven't got around to installing it. So my high temp readings on track were from the TVR sensor, which is not known for its accuracy. I did notice that, after one10 lap session on the track, I came into the pits with the gauge showing a pleasing 90 degrees, only to find, when I turned the ignition back on 15 minutes later that it was saying 115 degrees. Heat soak, given the proximity of the glowing turbo to the sensor I guess, but what was the truth? I never had any of the normal sounds of overheating that you would hear from a road car with issues, eg steam, gurgling in the cooling system, water on the floor.

Second mod it to install an oil temperature gauge. Oil temperature is possibly more important in protecting the engine from excess heat.


I have to make a comment here - I am used to my TVR temperature gauge reading between 70 and 85 degrees (other readings are available) in normal road running, and I tend to get anxious when the temperature approaches 90. Yet on every other road car i own, the water temp gauge always sits at 90 degrees and never varies. I guess the truth is two fold - water under pressure boils at well over 100 degrees, so even 90 degrees is perfectly safe, and a typical Audi temperature gauge only has 3 positions - "off", "running" and "knackered". The actual reading is meaningless.

[Brithunter]

" and a typical Audi temperature gauge only has 3 positions - "off", "running" and "knackered". The actual reading is meaningless."

Sadly you have just described many modern cars temp guages. The BMW inspired MG-Rover one in their late cars are the same. By the time it is moving up from normal the engine is over heating. Stupid idea.

[Pupp]

Trust me, you'll know if you properly overheat it

Why not use the Emerald logger to verify gauge readings are something like what the ECU is seeing? Not necessarily any more 'accurate' of course but mine has proved to be pretty close to what my SPA digital gauge reads (calibrating that was a whole load of fun mind).

Turbo with no cooler on track? Brave man - I was seeing regular +125C oil temps at the pressure switch gallery just on the road and that was with a ball-bearing CHRA on a larger turbine housing (ie less 'restrictive') - on another SPA gauge. Still well inside what good oil will deal with but a decent sized cooler easily reduced that by 20 deg.

Water and oil temperatures are telling you completely different things BTW - both are important

[QBee]

Useful info thanks - I am still very much learning.

I do run an oil cooler and an intercooler with the turbo, and suffer no heat issues on the road, just on the track. This could be because I reserve play time for the track, to preserve my licence and to be safe.

So I run the car at 2.5 psi boost on the road, 315 bhp, 395 ft lbs. Perfectly adequate for 99% of all road situations. I can click the map switch over to 6psi (372 bhp) or 7.5 psi (395 bhp) at will, no need to stop, just a slight lift for safety if over 3000 rpm.

It's only on track, running over 3000 rpm and at 7.5 psi boost for 85% of the lap that I get heat issues.

I will have a go with the data logging on the Emerald. Just need to get familiar with the software. I have established comms with my Laptop. Small issue of how to throw it around the track with an expensive laptop in the footwell, but the answer probably lies in a Windows tablet with a USB port

Edited by QBee on Thursday 7th September 08:05

[DonkeyApple]

What's more important in cooling? Additional cooling of the water or oil? I've always thought the former. If that's correct could you re-core your rads to increase the cooling ability and then just blank one half off during road use?

[QBee]

Need some expert guidance here.

I was of the impression that both oil and water need to be up to operating temperature, but not too hot, so in an operating window.
On the road my car copes well with the additional heat of the turbo. The fans probably run a little more often, but there is sufficient air getting through the radiator to keep everything in that operating window, despite about half the air having to pass through the intercooler first. Pic to save 1000 words - the intercooler is the silver thing behind the number plate. I remove the plate on track



I will review my oil cooler capabilities once I have an oil temp gauge installed. I only fitted a relatively small one, in the slots in the front valance (low down, driver's side).

[ChimpOnGas]

AceOfHearts said:

ITVRI said:

Aceofhearts. I think I remember reading that you undertook your turbo conversion on a high mileage engine. Any problems with it so far?

Its been in a year now and the standard engine is holding up absolutely fine (including 2 drag days!)

It is currently on 118,000 miles and has never been opened, and as far as i can tell is still on the original cam!

Running 10psi boost with no complaint and still uses no oil. I was kind of hoping to blow it up as an excuse to build a nice forged 4.5 for it but no luck yet

This is very impressive, how many miles have you put on the engine since going FI?

How exactly do you manage crankcase ventilation now?

What engine management system do you run?

Thanks, Dave.

[DonkeyApple]

Has anyone ever calculated the effect of our radiators being at such an oblique angle? It must have an impact.

The biggest impact I ever had to cooling was the installation of Spal ceramic fans that run via the ECU. The temp just sits at 88. The fans seem to flow considerably more air and the ECU controlling their speed also must help.

[QBee]

DonkeyApple said:

Has anyone ever calculated the effect of our radiators being at such an oblique angle? It must have an impact.

The biggest impact I ever had to cooling was the installation of Spal ceramic fans that run via the ECU. The temp just sits at 88. The fans seem to flow considerably more air and the ECU controlling their speed also must help.

I will look into that avenue....thanks