bi-turbo gt v6 (z7u)

That's mental

I can believe 350-370..for 'the spec'

Quality and the installation is considering factor though...

Didn't I just read "standard collectors" ? In other words, a standard pair of manifolds.....

@david

the idea was the sequential set up to have a streetable system combined with ultimate performance. the car picks up boost around 1700-1800 and around 3800 the second blower starts to phase in. at 4100 you have full boost. just gorgeous.

by the way the car is fully in street trim, with working a/c, complying with noise levels and emission standarts. everything is registered, so i had to pass full cycle emission testing on the dyno.

for racing you could as well go the single turbo route, i think power wise it wouldnt make any difference and you would probably get the benefit of overboost when changing gears. (then the down pipe should be 4 in. anyways.) alternatively you could switch the exhaust manifolds and place the turbos immediately at the outlets. i have seen such set ups run sucessfully. there is a trade off between the lengths of the exhaust and the intake trackts.

@monkey

standart manifolds that is, sorry my english is getting bad.

@david

the idea was the sequential set up to have a streetable system combined with ultimate performance. the car picks up boost around 1700-1800 and around 3800 the second blower starts to phase in. at 4100 you have full boost. just gorgeous.

by the way the car is fully in street trim, with working a/c, complying with noise levels and emission standarts. everything is registered, so i had to pass full cycle emission testing on the dyno.

for racing you could as well go the single turbo route, i think power wise it wouldnt make any difference and you would probably get the benefit of overboost when changing gears. (then the down pipe should be 4 in. anyways.) alternatively you could switch the exhaust manifolds and place the turbos immediately at the outlets. i have seen such set ups run sucessfully. there is a trade off between the lengths of the exhaust and the intake trackts.

Yes, indeed. With one turbo there has a big problem on the original single setup due to the manifold/link pipe design.

Im confused how you think your system is sequential, maybe it is but not correctly. You may have valving in the exhaust system but you also need valving in the inlet between the two turbos to shut off the boost of the first simply blowing out of the second.. as per this pic..



Have you got any run data, dyno run plots though?

double post

Didn't I just read "standard collectors" ? In other words, a standard pair of manifolds.....

Collectors, ie the bit at the head with the flexi most likely...

A little far off an original manifold if it has a turbo on each one and sequential bypass pipes and valving on it...

yes, i was waiting for this. actually i realised only today, when looking at my pictures, that the air valve is missing. i used to take it off and disable the exhaust valve for the track. i used a one way valve from an ABB comprex unit (brown plastic) that is simply spring loaded. it fits in place of the longer runner going into the intercooler. iam not sure where to look for it. when i find it, i make a picture.

Amazing. How much did this all cost you (if it's not a rude question) - I assume you did the labour yourself?

Oh and how do you change the spark plugs again

you lot are MENTLE

[phildini]

Spaghetti junction in that engine bay

@darren

i dont remember, but it sure cost me three years of my spare time. im surprised my wife didnt get a divorce, since i spent my weekends tuning the maps even after that.

on second thought, how much is two turbos, some stainless piping, heat shields and hoses? a hks intercooler core, sequential blow off valve and the welding farmed out (i tack welded everything myself)? not really that much. the motec is not really necessary, the car ran almost as well without it, it just gives you endless possibilities to spend your time.

hmmm...

Do you agree that the standard fuel injectors were OK?

i dont really remember, but i think they are 300 cc. they are completely maxed out, at roughly 4.5 bars pressure, though. (i have this something-jetronic pump from an A8.) i dont even think about getting larger ones, as the next step would be methanol injection and another two or three degrees of timing. the system is already in place, with an alcohol tank, pump, regulator and injector (experimental, never really used). i would go for a pulse controled injector, if i ever get back to that project, but they are just so expensive in the size recquired. the timing advance alone is worth another 5 % in power i believe.