92 replies to this topic

[rick.spi]

but the fuel consumption and reliabilty would be alot worse on the supercharged which is not ideal on a road car either...

im not trying to say there awefull just comparing to a another high spec engine, i still think the price is much to exessive for the benfits on a supercharged lump?...

Edited by rick.spi, 02 March 2010 - 07:07 PM.

[yeti21586]

has anyone considered a supercharged turbo???

[mini.cooper998]

started considering it yeti. my question still comes back to a blow through supercharger what are its limits

[Sam Walters]

To get big power from a super charger your going to have to run a big cam for starters as well as the fabrication work involved for a blow through setup.
A GT17 turbo seems to a good weapon at this moment in time. i mean over 100 lbs/ft @ 2800 rpm.



Image pinched from turbominis.co.uk

[Prawn]

that's a pretty epic graph isn't it! I wish robert would give away some details about his cam!

From memory, I believe robert said that the blue curve is at 12psi, red curve is at 15psi, and the green curve is at 16psi. running 16 degrees timing with no IC fan. if I get anywhere near that at all I'll be over the moon!

[mini.cooper998]

surely cams are very specific for turbo supercharged engines due to the overlap you down want to be blowing the charge streight through after all.

what engine spec is he running to achieve that kind of power becasue thats high.

[mini13]

lightly (home) ported head, and a gt17 turbo and the cam mentioned above, the rest is fairly standard.

[MarkGTT]

heres mine for comparason on a T3, although i dont get much lag i think the boost is more efficiant with a GT17.

[Wil_h]

Yes, the compressor (and importantly) the turbine are very efficient on the GT17. I gaind 15bhp for no extra boost fitting one.

[[email protected]]

Out of interest, how readily available are GT17's and manifolds for them etc?

[MarkGTT]

Out of interest, how readily available are GT17's and manifolds for them etc?

buy a new one for arround £400 - £500 most the second hand ones seem to be scrap.. the manifold need to be a custom job or you need an adaptor plate for the metro turbo manifold.

[mini.cooper998]

what cars and year / model was the GT17 fitted too

[MarkGTT]

what cars and year / model was the GT17 fitted too

GT1752 - Saab 9-5 / 9-3 think it is 1997 on, you will have to search the web.

[Turbo Nick]

i'd say a gt17's as big as you want to go on a road car, mines the next one up a gt20 and is about the same lag wise as a std t3 but a lot more efficient.

i've still got a few little things left to tweak and maybe a cam change to nudge the boost threshold a bit lower if possible. i think upping my rev limit will release a few extra banana's up top too.

[Wil_h]

Go to www.crturbos.co.uk and plug GT1752 into the search to see what they are fitted to. CR turbos will rebuild a 17 for £300.