Turbo Reasonably Effecient At 16psi

[Wheezy]

3037s with the .68 housing. both have had awesome rsults on sr20 motors so should be close to rb20s

anyone got a dyno sheet with this snail on a sr or RB20?

[discopotato03]

In the past HKS marketed the GT3037 (GT3076R - Garrett speak) in 48 and 52 trim along with the far more common 56 trim compressor . The 48T version seems to have fallen off the edge of the planet which is a pity . The 52 trim version is the sweet spot and quite a few Americans have found this out on their SR20's . I used to haunt their SR20 sites in my FJ20 days and they often said that the spool or boost threshold characteristics varied by 5-600 rpm between the 52 and 56 comp trim 3037 versions . 5 to 600 rpm makes a HUGE difference on a 2 Litre four , more so than the few mm of inducer size and drop from .60 to .50AR compressor cover size would have you think . They still flogged approx 400 wheel Hp out of the "Japanese Coventry Climax Pump motor" so the optimal trim GT3037 is no whimp .

Even though Garrett manufactured the GT3037/GT3076R they were only sold to HKS in those days . Garrett fobbed the rest of us poorpers of with the pathetic GT30/TO4S variants which are still with us and finding more victims . In the recent past Garrett decided to offer the GT3076R to all but only in 56 compressor trim . I was talking recently to someone who worked for Garrett in the US and he said that market forces have a large say in what they make and sell . They narrowed the GT3076R in the US down to 56T because thats what the market demanded so thats what they produced . So sady mores law means that only the laggy 56T is reasonably easily to obtain . Nothing stopping you buying a 52 trim GT3037 and flicking the T28 flanged turbine housing for a T3 flanged one but its expensive .

The point of all this is that HKS offered smaller trim compressors and turbine housings down to .73 and .61AR so that they would be good responsive things on CA18's , SR20's and probably RB20's/25's .

We've been lumbered with the sledgehammer for walnut option so now you all know why the GT3076R/GT3037 56T turbos are so laggy on SR20's , RB20's and RB25's .

Cheers A .