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Discussion Starter #1
forget big power, what's the best setup for minimal lag as well as lowest boost threshold (rpm when they kick in)? I'm assuming cams will have to be a part of such a formula, what type (lift/duration)? And such a setup can be pushed up to how many hp at the flywheel?

are the stock R32/R33 ceramics the least laggiest/quickest responding turbos in the GTR world?
 

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Discussion Starter #3
lots, and lots, and lots of talk on turbos, but is there any consensus on a turbo/cam combination for fastest spool and low end power?

Do GT-SS turbos really spool faster than stock ceramics??
 

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I drove my gt-ss equipped gt-r for 6 months. Boost initially came on almost exactly (perhaps 200rpm later) than stock turbos. The real difference being they started to pull much harder at around .5 bar. No one who ever has driven gt-ss turbos would complain about lag. It is about as non existent as it gets.
My t88 equipped car, different story !!!!!:smokin:
 

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I loved my GT-SS turbos, especially married with 260 poncams - it certainly use to embarrass many a larger laggier turbo'd equipped GTR :).

A bigger capacity block as well and you are as close to lag free as you will get :)
 

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Discussion Starter #7
restrict? in what way? You mean the GT-SS housing, or the engine compression ratio?
 

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Or go for the standard ceramic R34 roller ball bearing turbo.

I think it is the smallest garrett GT turbo you can get on the GTR, still good for 450bhp+, and can spool 1bar by 2500rpm with a set of Tomei 260 PonCAM.

Max boost at 1.15bar.

You will need ECU, turbo elbow and front pipe for all the those mod, but then so does GT-SS.
 

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Discussion Starter #9
already have the ecu and piping, 1 bar at 2500rpm is very awesome, very impressive indeed!
 

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i was flipping through my hyper rev book and couldnt help but notice one the R33 gtr engine output figures.

[email protected]
[email protected] (is it possible?could this mean virtually no lag or really low boost threshold?)

GTSS running 1.0bar
2771cc
87mm bore
600cc injectors
inlet 248deg,8.8mm lift
exh 264deg,10mm lift
trust intercooler
nismo plenum
Vcam pro step 1
 

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If I had to guess I would have said the ss.

But
2510's have smaller turbine wheels but larger compressor wheels than the ss.

Be close I think.

Also hows the 2560 equivilent look on paper ?
 

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Variable vain or n2o.

going to 10.0.1 or such wouldn't hurt either for spool. K20 guys are boosting their motors on that cr, some even higher with stock c/r.
 

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Discussion Starter #15
wow, I've come a long way in two and a half years.

The answer is:

Mapping. Driver technique. Air/fuel ratios during spoolup must be set to produce the hottest EGT you can manage. That's about 35% of the equation. The rest? Don't let the turbos stall when driving!

Last night's flog, I was able to have full boost in 2nd at 3500rpm, and 5500rpm. Depends on how I handled 1st. Even if I blow 1st gear in a lot of tirespin and not much forward motion, I can still avoid lag in 2nd by slipping the clutch to keep the turbos on boil.

Lag is when you've got no boost, you're puttering at 2000rpm, and then floor it and surprise surprise, nothing happens until over 5000rpm, and it's a CRAWL through that 3000rpm band. I forget who said it, but I now understand - there is no such thing as turbo lag, just lazy throttle application.
 
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