interesting turbo engine build
- Thread starter 944Turbo
- Start date
Very interesting - a very different approach - 2.7, 16v, huge turbo, wild cams, loads of revs (7500!).
Assuming he's on the standard Turbo gears and final drive, it's geared for 190 mph at 7500 rpm, and with 676 bhp at those revs it will get there in a big hurry.
Be interesting to see how it holds together.
Assuming he's on the standard Turbo gears and final drive, it's geared for 190 mph at 7500 rpm, and with 676 bhp at those revs it will get there in a big hurry.
Be interesting to see how it holds together.
TTM
Well-known member
According to the compressor map of the latest turbo tested (T04Z) and considering how much boost is used and how much backpressure is measured, this turbo may be way too small for achieving these figures reliably over the long run.
I would be curious to know the levels of air intake temperature measured, maybe not too much if the intercooler is drowned in cold water like is the case with most proper engine dynos, but it may be a different kettle of fish when the IC is on the car, exposed to "only" the flow of ambiant air.
This engine would certainly enjoy a bigger turbo such as a GTX3582R to run that much boost in a more comfortable fashion.
I would be curious to know the levels of air intake temperature measured, maybe not too much if the intercooler is drowned in cold water like is the case with most proper engine dynos, but it may be a different kettle of fish when the IC is on the car, exposed to "only" the flow of ambiant air.
This engine would certainly enjoy a bigger turbo such as a GTX3582R to run that much boost in a more comfortable fashion.
Agreed Thom and Paul. I absolutely salute Tim for his build and am really happy that someone from outside of this 'community' has chosen to build such a motor. Perhaps the lack of preconception might have allowed him some more freedom from the normal attitudes regarding these motors.
I would love to see his dyno and ign charts. Running 32psi on pump fuel is pretty unconventional. Sure, the 16v heads are more resistant to knock but this is certainly pushing the boundaries. Not sure how long the 265mm rears will last. [
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I would love to see his dyno and ign charts. Running 32psi on pump fuel is pretty unconventional. Sure, the 16v heads are more resistant to knock but this is certainly pushing the boundaries. Not sure how long the 265mm rears will last. [
]
Yes, I dare say that in addition to big intercooling it will have to have something fairly clever in the radiator department. Fun on the road though - and in reality on the road it won't have time to get very hot with the very few opportunities you get to apply full power for more than a couple of seconds at a time.
TTM
Well-known member
The turbos he mentioned testing are certainly excellent choices for the 2.0L Cosworth engines he has a background with.
I'm really hoping he will be motivated enough to try some larger ones. I reckon there is the potential to go beyond 750bhp here, well at least on a engine dyno.
George Elliott
New member
As others have said, its so refreshing to see a 16v, short stroke, 944 turbo with big cams and a scratch ecu.
Cosworth engineering technology is right up there, the merc 190 16v, and audi rs4 benefitted from it with impressive results, but for me they tend to apply their expertise to fragile ford engine platforms.
I realise turbotim3 is not Cosworth but is very familiar with their technology. Interestingly, he seems to like the m44/xx engine and has certainly made it rev. Those boost numbers are off the scale of what we are familiar with. (unless the wastegate jams shut [8|])
Well done Tim, have a word with Stefan Rosser, and lets have a "White Bird" video to superseed Yellowbird at the ring.
George
944t
Cosworth engineering technology is right up there, the merc 190 16v, and audi rs4 benefitted from it with impressive results, but for me they tend to apply their expertise to fragile ford engine platforms.
I realise turbotim3 is not Cosworth but is very familiar with their technology. Interestingly, he seems to like the m44/xx engine and has certainly made it rev. Those boost numbers are off the scale of what we are familiar with. (unless the wastegate jams shut [8|])
Well done Tim, have a word with Stefan Rosser, and lets have a "White Bird" video to superseed Yellowbird at the ring.
George
944t
Hi Guys, Well I see you have all read my thread and found the build interesting, I hope. Well I am after some advice, as you all have turbo cars, with various levels of power. I would like to know what sort of power you think the rest of the car is up to, areas like gearbox, driveshafts, clutch and torque tube. How does the 944 handle and feel with big power. The dilemma I have is, should I go for more power just to see what the engine is capable of and risk breaking it, or just map it on a smaller turbo to something more realistic, which the car is able to handle.
I look forward to reading your comments.
Cheers Tim
I look forward to reading your comments.
Cheers Tim
The gearbox will probably not like the power/ torque you are putting out. I think there are some guys over on rennlist who may have address this issue to a point but not at the levels you are running. The 968 box is a potential upgrade but the ratios are too short as is it, even more so for your power curve. So far no one has been able to source a reasonably priced upgrade to the final drive, maybe with your motorsport contacts this might be possible? I guess the other point is how much power will you actually run when the engine is installed as you still have to overcome the limits of the in situ air and water cooling. I just tested my new front mount intercooler design at the dyno yesterday and it has worked very well, see the thread I just posted. But I am not running anywhere near your boost levels, however I am confident it is man enough for the job and could be tweaked to provide more cooling with a slightly different core. I used a pro-alloy core similar to that used on some of the cosworths for its course nature to flow enough air through to the rad.
TTM
Well-known member
The way I see it is that you have been looking for making a high-revving engine from the start (16V + short stroke), so why not slap a larger turbo, have a reasonably peaky engine feeling like a normally-aspirated one?
You really don't want to have too much low and mid range torque, which in my case was a pain on the road as it required much effort and restrain to keep the car at reasonable speeds, until a I eventually fitted a short runner intake maniold.
As you know the engine will be peakier with a larger turbo but it's crying for it and it should also be a lot more fun than a flat torque curve, which will put more strain on the drivetrain.
You really don't want to have too much low and mid range torque, which in my case was a pain on the road as it required much effort and restrain to keep the car at reasonable speeds, until a I eventually fitted a short runner intake maniold.
As you know the engine will be peakier with a larger turbo but it's crying for it and it should also be a lot more fun than a flat torque curve, which will put more strain on the drivetrain.
Diver944
Active member
My old car was way lower than your figures Tim with 397 bhp/480 lbft and it managed fine with the stock gearbox, driveshafts and torque tube etc for 10,000 miles and three trackdays before I sold it. It originally had the motorsport clutch kit but that started slipping after only a few thousand miles so was then replaced with a 930 disk and a KEP stage 2 pressure plate which held up fine.
I would add that it very much depends on how you drive it. Hard starts will break things like CV's, axles, gears, even torque tubes and bell housings in extreme cases. You can go crazy and buy or build custom everything to try to insure against these breakages but it gets expensive very quickly.
In actuality the power figures you've reached already will be too high for general use, but it's great to see what you can do on the engine dyno. I agree with Thom that a larger turbo will make a better choice for a few reasons. As mentioned on your Tipec thread, you can build a simple brace between the rear of the gearbox across to the chassis and restrict the lateral movement which has proved to be effective in reducing the amount of cracked CVs on the US cars who tend to drag race. I've done similar just as insurance. The rather expensive LR axles and CVs ($1200 pair!) are rated at high levels of tq but I'm not risking anything. My usage won't include hard starts so that's a bonus. Not sure, but I don't get the impression you're building this for drag racing or even traffic light racing Tim.
I think you'll need more rubber and better suspension. As most in here would agree, the KW offerings work very well on these cars. You can run up to 11" wide rears with a bit of creativity but I ran 10" all round easily. Just need the right offset. Looking forward to your next results. []
In actuality the power figures you've reached already will be too high for general use, but it's great to see what you can do on the engine dyno. I agree with Thom that a larger turbo will make a better choice for a few reasons. As mentioned on your Tipec thread, you can build a simple brace between the rear of the gearbox across to the chassis and restrict the lateral movement which has proved to be effective in reducing the amount of cracked CVs on the US cars who tend to drag race. I've done similar just as insurance. The rather expensive LR axles and CVs ($1200 pair!) are rated at high levels of tq but I'm not risking anything. My usage won't include hard starts so that's a bonus. Not sure, but I don't get the impression you're building this for drag racing or even traffic light racing Tim.
I think you'll need more rubber and better suspension. As most in here would agree, the KW offerings work very well on these cars. You can run up to 11" wide rears with a bit of creativity but I ran 10" all round easily. Just need the right offset. Looking forward to your next results. [
]George Elliott
New member
Tim,
firstly, don't blow the head off it. give it to me....[]
but seriously, from what you have posted, it is a very unique 944 turbo engine configuration, look after it.
As Patrick said - the answer to your question is it depends...on how you drive it. As you will know a car with 200hp is more fragile than one with 85hp, and that potential for damage increases as power increases.
Some people could drive your 500+ horse car for 50,000 miles and it would only need oil and tyres, others could break it inside 100 miles.
My experience with a much lesser (300 and a bit hp car) is that the running gear is exceptionally well engineered. The Clutch, Torque tube, transmission, diff, trailing arm units, are very durable. Of these the Diff is weakest, followed by the clutch, rough changes will knacker the 'box obviously. You will get some rear wheel steer under power at your levels, the VW type 2 descended rear end is good but you are asking a lot of it.
I would keep to 9" rear rims to let the pressure off the transmission. I can imagine two black parallel lines will be a frequent sight in the rear view mirror. Your car in the dry, would be like mine in the wet. [8|]
IF, you really want a solution, there is one, - it will spoil the character but make the worlds fastest 944t, find yourself an R35GTR transmission and 4 driveshafts.......[8|]
Good luck
George
944t
firstly, don't blow the head off it. give it to me....[
]but seriously, from what you have posted, it is a very unique 944 turbo engine configuration, look after it.
As Patrick said - the answer to your question is it depends...on how you drive it. As you will know a car with 200hp is more fragile than one with 85hp, and that potential for damage increases as power increases.
Some people could drive your 500+ horse car for 50,000 miles and it would only need oil and tyres, others could break it inside 100 miles.
My experience with a much lesser (300 and a bit hp car) is that the running gear is exceptionally well engineered. The Clutch, Torque tube, transmission, diff, trailing arm units, are very durable. Of these the Diff is weakest, followed by the clutch, rough changes will knacker the 'box obviously. You will get some rear wheel steer under power at your levels, the VW type 2 descended rear end is good but you are asking a lot of it.
I would keep to 9" rear rims to let the pressure off the transmission. I can imagine two black parallel lines will be a frequent sight in the rear view mirror. Your car in the dry, would be like mine in the wet. [8|]
IF, you really want a solution, there is one, - it will spoil the character but make the worlds fastest 944t, find yourself an R35GTR transmission and 4 driveshafts.......[8|]
Good luck
George
944t
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