Build me a turbo'd track car! -Pricing it up
Discussion
Your mission, should you choose to accept it...
I have a 1990 99k Mk1 Eunos 1.6; due to it drinking go-juice like [insert similie here] I've retired it from daily duties. I've decided I want a track car eventuall with about 250bhp (I used to race a fisher fury fireblade that was about 260 bhp/tonne, so that's my benchmark for fast track car).
I've been thinking about selling mine and getting one already done, or if the price isn't too much more expensive, using my car as a base and building it with my dad. I'd be building it up in phases over a period of time.
What do you guys think? What would the bits needed be? I have no problem with secondhand gear, I can be patient and I do have a budget to stick to (In total about £2.5k in mods, maybe more depending on the length of time it goes on) So £800 coilovers I can get used for £300 are welcome!
My initial thoughts are
Phase 1
Base car (free)
Roll hoop with back stays (not one of those poofy "style hoops") -already have in the shed
Decent tyres
Uprated brakes
Take out carpets and sound deadening
Phase 2
Coilovers
LSD
Phase 3
Turbo kit set to low boost
Phase 4
High pressure turbo
Intercooler
Aftermarket ECU
I'm sure I've missed loads, so if anyone has any ideas, let me know!
Thanks,
Dan
I have a 1990 99k Mk1 Eunos 1.6; due to it drinking go-juice like [insert similie here] I've retired it from daily duties. I've decided I want a track car eventuall with about 250bhp (I used to race a fisher fury fireblade that was about 260 bhp/tonne, so that's my benchmark for fast track car).
I've been thinking about selling mine and getting one already done, or if the price isn't too much more expensive, using my car as a base and building it with my dad. I'd be building it up in phases over a period of time.
What do you guys think? What would the bits needed be? I have no problem with secondhand gear, I can be patient and I do have a budget to stick to (In total about £2.5k in mods, maybe more depending on the length of time it goes on) So £800 coilovers I can get used for £300 are welcome!
My initial thoughts are
Phase 1
Base car (free)
Roll hoop with back stays (not one of those poofy "style hoops") -already have in the shed
Decent tyres
Uprated brakes
Take out carpets and sound deadening
Phase 2
Coilovers
LSD
Phase 3
Turbo kit set to low boost
Phase 4
High pressure turbo
Intercooler
Aftermarket ECU
I'm sure I've missed loads, so if anyone has any ideas, let me know!
Thanks,
Dan
Well you have a 1990 so it's about as light as they get but that also means the chassis isn't as stiff as it could be. Start with fitting the roll hoop (which one do you have?) and the usual front & rear chassis under braces. With roll bars it shouldn't need the rear tower brace.
If it has AC then you can remove that.
Removing the carpets & sound deadening removes a little weight but not a lot so if it's going to used on the road at all I'd leave it in. Same with stereo & speakers.
15" wheels would be good as tyres are cheaper which is important if you are going to do many track days. Until you fit uprated suspension I wouldn't bother with full track tyres though.
Brakes - fit uprated pads but leave the callipers & discs alone for now, they are fine for standard power. Change the brake fluid and the hoses (assuming they haven't been done recently).
As for more power - run it na first. My car has 243bhp and I use it on track but I have just as much fun driving the PlanetMX5 Motorsports car which is a Mk1 1.6 which probably has a fair bit less than the 114bhp it came with
If it has AC then you can remove that.
Removing the carpets & sound deadening removes a little weight but not a lot so if it's going to used on the road at all I'd leave it in. Same with stereo & speakers.
15" wheels would be good as tyres are cheaper which is important if you are going to do many track days. Until you fit uprated suspension I wouldn't bother with full track tyres though.
Brakes - fit uprated pads but leave the callipers & discs alone for now, they are fine for standard power. Change the brake fluid and the hoses (assuming they haven't been done recently).
As for more power - run it na first. My car has 243bhp and I use it on track but I have just as much fun driving the PlanetMX5 Motorsports car which is a Mk1 1.6 which probably has a fair bit less than the 114bhp it came with
You'll need a decent radiator for track work, especially as the turbo is introduced; I'd include it in your stage 3 section. I got a high capacity aluminum radiator from eBay for £150.
I'm assuming your roll bars are capable of protecting the occupants in the event of a rollover, and not just style bars? If not, price one in, TR Lane units are about £300. I wasn't going to bother for mine, but then saw some rather convincing videos on YouTube; you wont go on track without one if you watch them.
Although not essential, you might want to spec some bucket seats with harnesses. Elise S1 seats fit, although you might need different runners, someone here should be able to advise. I picked up some 2nd hand Cobra Monaco's for £170, and harnesses will be about £60 or so.
To achieve 250BHP or so in stage 4 you'll be running the standard engine close to it's limits, you may need to look at a Wideband sensor so that the aftermarket ECU can correctly look after it's fuel inputs. You might also want to look at water injection to keep things as safe as possible.
I think Flyin' Miata's website has a comprehensive list of all the componants and the prices that make up their turbo kits, it should give you a starting point for understanding what you'll need to purchase.
Although £2.5k should go a fair way, I think you'll struggle to get everything you need for a 250BHP build. It should, however, be enough to get you into a basic setup good for 150-170BHP.
Hope this helps, if anything else springs to mind I'll add further to your thread.
I'm assuming your roll bars are capable of protecting the occupants in the event of a rollover, and not just style bars? If not, price one in, TR Lane units are about £300. I wasn't going to bother for mine, but then saw some rather convincing videos on YouTube; you wont go on track without one if you watch them.
Although not essential, you might want to spec some bucket seats with harnesses. Elise S1 seats fit, although you might need different runners, someone here should be able to advise. I picked up some 2nd hand Cobra Monaco's for £170, and harnesses will be about £60 or so.
To achieve 250BHP or so in stage 4 you'll be running the standard engine close to it's limits, you may need to look at a Wideband sensor so that the aftermarket ECU can correctly look after it's fuel inputs. You might also want to look at water injection to keep things as safe as possible.
I think Flyin' Miata's website has a comprehensive list of all the componants and the prices that make up their turbo kits, it should give you a starting point for understanding what you'll need to purchase.
Although £2.5k should go a fair way, I think you'll struggle to get everything you need for a 250BHP build. It should, however, be enough to get you into a basic setup good for 150-170BHP.
Hope this helps, if anything else springs to mind I'll add further to your thread.
crofty1984 said:
poofy "style hoops"
crofty1984 said:
Phase 3
Turbo kit set to low boost
Phase 4
High pressure turbo
Intercooler
Aftermarket ECU
I'm sure I've missed loads, so if anyone has any ideas, let me know!
Dan @ Universal intercoolers does a complete intercoloer kit for round about £230 i think, which includes all the pipework etc. Or I'm pretty sure his "small" (the size most mx5s run) intercooler is <£100 and you can make your own hard pipes and source your own hoses. I'd move your ECUTurbo kit set to low boost
Phase 4
High pressure turbo
Intercooler
Aftermarket ECU
I'm sure I've missed loads, so if anyone has any ideas, let me know!
You'd also need to run bigger injectors once you got to phase 4, but I'm not sure what kind of cc you'd require. I know second hand options are available, people use RX8 injectors but I don't know what they can flow.
IIRC the standard ECU can't cope with any boost so you'd need some kind of aftermarket system for phase 3.
Oh and a clutch, you'll need one of those at phase 4 too.
Mr MXT said:
You'd also need to run bigger injectors once you got to phase 4, but I'm not sure what kind of cc you'd require. I know second hand options are available, people use RX8 injectors but I don't know what they can flow.
Good spot. If I remember rightly, RX injectors are 380cc. I've some 550cc injectors on mine, they're bigger than required and I've no idea what they're from though!Mr MXT said:
IIRC the standard ECU can't cope with any boost so you'd need some kind of aftermarket system for phase 3.
This is where things start to get pricey too, and you need to ensure that your ECU is pretty sophisticated if you wish to go as far as 250BHP. I'm using a LinkECU G4; they're around £1300 to purchase, and you'll need £300 for the mapping. You can do it yourself, but if you get it wrong you'll be starting again with a new engine!Megasquirt ECU's seem to be a more popular option, but I don't know anything about them.
piefacemate said:
Mr MXT said:
You'd also need to run bigger injectors once you got to phase 4, but I'm not sure what kind of cc you'd require. I know second hand options are available, people use RX8 injectors but I don't know what they can flow.
Good spot. If I remember rightly, RX injectors are 380cc. I've some 550cc injectors on mine, they're bigger than required and I've no idea what they're from though!Mr MXT said:
IIRC the standard ECU can't cope with any boost so you'd need some kind of aftermarket system for phase 3.
This is where things start to get pricey too, and you need to ensure that your ECU is pretty sophisticated if you wish to go as far as 250BHP. I'm using a LinkECU G4; they're around £1300 to purchase, and you'll need £300 for the mapping. You can do it yourself, but if you get it wrong you'll be starting again with a new engine!Megasquirt ECU's seem to be a more popular option, but I don't know anything about them.
I have 550cc injectors too - RC for me! In my opinion, injectors are all around the same price so if you are fitting an aftermarket ecu that can handle bigger injectors they might as well be big enough so that they aren't stressed at all at peak flow. I have an Adaptronic 420C ecu which cost me £1200 including IAT sensor, plug & play harness and the injectors.
Personally I'd rate an oil-cooler as more important than a radiator upgrade with FI. Keeping the oil cool will help keep the coolant cooler anyway. Before I fitted my Twincooler (combined oil & coolant radiator) I used to see very high oil temps but the coolant temps were fine (high but ok).
And... if we are getting to the nitty-gritty and detailing all the parts that need upgrading for a 250bhp turbo track car you also have to include the downpipe, cat (or bypass), and the rest of the exhaust system. To keep a 250bhp turbo spooling up quickly you need the exhaust system to be much better flowing that the stock system.
I would say though that 250bhp is more than enough for an MX5 track car. 200bhp is probably nearer the mark for a perfectly balanced Mk1 1.6 on track. It's also a lot cheaper and will stress the engine less. My Mk2.5 has 243bhp but it's mainly a road car that I use on track and it's also a fair bit heavier than a 1990 Mk1
Personally I'd rate an oil-cooler as more important than a radiator upgrade with FI. Keeping the oil cool will help keep the coolant cooler anyway. Before I fitted my Twincooler (combined oil & coolant radiator) I used to see very high oil temps but the coolant temps were fine (high but ok).
And... if we are getting to the nitty-gritty and detailing all the parts that need upgrading for a 250bhp turbo track car you also have to include the downpipe, cat (or bypass), and the rest of the exhaust system. To keep a 250bhp turbo spooling up quickly you need the exhaust system to be much better flowing that the stock system.
I would say though that 250bhp is more than enough for an MX5 track car. 200bhp is probably nearer the mark for a perfectly balanced Mk1 1.6 on track. It's also a lot cheaper and will stress the engine less. My Mk2.5 has 243bhp but it's mainly a road car that I use on track and it's also a fair bit heavier than a 1990 Mk1
piefacemate said:
Good spot. If I remember rightly, RX injectors are 380cc. I've some 550cc injectors on mine, they're bigger than required and I've no idea what they're from though!
RX injectors come in a few sizes, none are 380cc though... I had a set of FC RX7 primary injectors fitted to my car, they're 550cc and after cleaning and flowtesting actually pushed out 600cc.
I've since changed these for RX8 primary injectors which flow 425cc and are of a far superior spray pattern. I changed for this reason and the fact I was only hiting 68%DC.
Always pick the injector size for your power level, don't just get the bigest size you can find. Bigger injectors require smaller pulse widths at low rpm/idle, extremely small PW's means even a tiny change in PW means a large deviation in the amount of fuel delivered (plus injectors are partly non-linear in delivery at very low PW's), it all adds up to a hard to tune idle, particularly at stoich.
piefacemate said:
IIRC the standard ECU can't cope with any boost so you'd need some kind of aftermarket system for phase 3.
Personally I'd suggest an aftermarket ECU should be the 1st thing you change, not the last, having time to learn the system is invaluable, plus as you state the OEM ECU doesn't have any capacity to detect positive intake manifold pressure so you're relying on bandaids to supply the fuel - AFPR, Powercard etc - whilst these do work to geater or lesser degrees, it's kind of pointless to spend the money on them and suffer the drivability issues if you're only going to replace them at some point anyway.piefacemate said:
This is where things start to get pricey too, and you need to ensure that your ECU is pretty sophisticated if you wish to go as far as 250BHP. I'm using a LinkECU G4; they're around £1300 to purchase, and you'll need £300 for the mapping. You can do it yourself, but if you get it wrong you'll be starting again with a new engine!
250bhp isn't any great shakes in the MX5 to be honest. As for ECU sophistication, the FM LINK is not a sophisticated ECU, for example it's fuel and ignition tables - whilst interpolated - are only 5x8 in size, but it does a sterling job on an MX5. You do need a standalone or parallel ECU for that power level though so something like the eManage Blue is definately out.You don't need to spend £1300 on an ECU to reach 250bhp either
.I tend to advise people to decide whether they 1) want to tune themselves or 2) have someone else to do it.
If the answer is 1) Pick an ECU with the best support available, whilst your learning the ECU's foibles this is invauable. If the answer is 2) Then pick the ECU you tuner is most comfortable with. There's no point buying an ECU your tuner has never used, as whilst he will be able to tune it, you'll be paying him whilst he spends a lot more time figuring out how it works
Tuning your own engine isn't hard, you just need to be cautious and do a bit of research prior to starting, I'd never tuned an engine 6 years ago and mine, (and my mates engines) are still running perfectly.
[quote]
Megasquirt ECU's seem to be a more popular option, but I don't know anything about them.
MX-5 Lazza said:
Personally I'd rate an oil-cooler as more important than a radiator upgrade with FI. Keeping the oil cool will help keep the coolant cooler anyway. Before I fitted my Twincooler (combined oil & coolant radiator) I used to see very high oil temps but the coolant temps were fine (high but ok).
Interesting, I've been pondering whether I need to improve my cooling before (finally) getting it out on track - has an good condition standard radiator but also the coolant re-route done by previous owner.Would be interested to compare water temps with others - it usually sits around 70-80° when cruising and I've seen it up to ~94° a couple of times, once in very hard road driving (repeated back and forth runs for a camera) and once in stop-start traffic on a 35° day. The trackdays I usually do are run as 5-lap sessions, think the cooling is likely to be an issue?
PS to add to other questions, mine is also running 550cc injectors (Mazda Cosmo I think) and Link ECU.
Edited by GravelBen on Wednesday 23 February 12:19
Remember, one of the tasks of the coolant is to cool the oil. If the oil is cooler then the coolant has an easier job and can stick to it's main task of cooling the head & cylinders! I'm not saying a more efficient coolant radiator isn't going to be needed, just that oil cooling is very important on an FI car.
5 laps don't sound much but what will the air temps be, how long are the tracks and how much of that time will be WOT? Before I fitted my oil-cooler I was limited to about 10 minutes on track before the oil temp got too high and I came in to let it all cool down.
5 laps don't sound much but what will the air temps be, how long are the tracks and how much of that time will be WOT? Before I fitted my oil-cooler I was limited to about 10 minutes on track before the oil temp got too high and I came in to let it all cool down.
GravelBen said:
Interesting, I've been pondering whether I need to improve my cooling before (finally) getting it out on track - has an good condition standard radiator but also the coolant re-route done by previous owner.
Would be interested to compare water temps with others - it usually sits around 70-80° when cruising and I've seen it up to ~94° a couple of times, once in very hard road driving (repeated back and forth runs for a camera) and once in stop-start traffic on a 35° day. The trackdays I usually do are run as 5-lap sessions, think the cooling is likely to be an issue?
PS to add to other questions, mine is also running 550cc injectors (Mazda Cosmo I think) and Link ECU.
You temps soound completely normal. the re-route will help a fair bit on-track, as will ensuring all air entering the mouth of the car actually goes through the radiator.Would be interested to compare water temps with others - it usually sits around 70-80° when cruising and I've seen it up to ~94° a couple of times, once in very hard road driving (repeated back and forth runs for a camera) and once in stop-start traffic on a 35° day. The trackdays I usually do are run as 5-lap sessions, think the cooling is likely to be an issue?
PS to add to other questions, mine is also running 550cc injectors (Mazda Cosmo I think) and Link ECU.
Edited by GravelBen on Wednesday 23 February 12:19
Block off all gaps around the rad and ensure all the ducting is secure, duct tape is helpful
That said, even 'very hard' road driving isn't even remotely comparable to driving on track. very hard road driving for camera shots would be a few pulls in 2nd/3rd? then slow down turn around and repeat?
On track you're permanetly at WOT, and if you're not you're standing on the brakes and ready to go WOT again. Don't expect to get more than 10-15 minutes before the car starts to overheat.
Here's a list. Some are necessary, some are optional but will be very useful in making a reliable car.
[LIST]
Turbo manifold
Downpipe
Turbo
Oil feed & return for turbo
Water feed for turbo
Exhaust - 2.5" or wider
Decat / sports cat
Injectors
Intercooler + pipework
Blowoff valve
ECU
Clutch
Wider wheels / tyres
Radiator / coolant reroute
Wideband sensor & Gauge
New coolant hoses (they'll split)
Knock sensor
Oil temp gauge, water temp gauge
Oil cooler
W.I kit
Coilovers
Bigger brakes
Performance pads
Roll bar
Bucket seats + harnesses
Heatwrap (to protect other components)
Boost gauge
Cone Filter
[LIST]
Turbo manifold
Downpipe
Turbo
Oil feed & return for turbo
Water feed for turbo
Exhaust - 2.5" or wider
Decat / sports cat
Injectors
Intercooler + pipework
Blowoff valve
ECU
Clutch
Wider wheels / tyres
Radiator / coolant reroute
Wideband sensor & Gauge
New coolant hoses (they'll split)
Knock sensor
Oil temp gauge, water temp gauge
Oil cooler
W.I kit
Coilovers
Bigger brakes
Performance pads
Roll bar
Bucket seats + harnesses
Heatwrap (to protect other components)
Boost gauge
Cone Filter
Edited by mk1salami on Wednesday 23 February 16:20
Richyvrlimited said:
You temps soound completely normal. the re-route will help a fair bit on-track, as will ensuring all air entering the mouth of the car actually goes through the radiator.
Block off all gaps around the rad and ensure all the ducting is secure, duct tape is helpful
That said, even 'very hard' road driving isn't even remotely comparable to driving on track. very hard road driving for camera shots would be a few pulls in 2nd/3rd? then slow down turn around and repeat?
On track you're permanetly at WOT, and if you're not you're standing on the brakes and ready to go WOT again. Don't expect to get more than 10-15 minutes before the car starts to overheat.
Thanks, yep ducting around rad etc is already done.Block off all gaps around the rad and ensure all the ducting is secure, duct tape is helpful
That said, even 'very hard' road driving isn't even remotely comparable to driving on track. very hard road driving for camera shots would be a few pulls in 2nd/3rd? then slow down turn around and repeat?
On track you're permanetly at WOT, and if you're not you're standing on the brakes and ready to go WOT again. Don't expect to get more than 10-15 minutes before the car starts to overheat.
Agreed that road driving isn't the same, added that for comparison as I haven't had this car on track yet to find out.
The circuits I'll be on are mostly relatively short (sub-3km) and technical, lap times in standard MX5 were between 1:20 and 2:05 so it sounds like 5 lap sessions should be fine. Air temps could be anywhere from 5-30° in April (when I have a few days booked) but most likely 15-20ish so not too bad.
An oil temp gauge is probably a good idea to keep an eye on things, guess I can always wind the boost down a bit if I have to on the day.
Edited by GravelBen on Wednesday 23 February 23:53
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