Tom Tucker

100mm stroker

In my experience, I would look no further than a 7670 1.05 T4. On my 2.3L Evo, the thing was insane. 30 psi by 3750rpm, at 4000rpm it was making 250kw and 530nm of torque. Then went on to 410kw. But on 98 on 20psi, it was also perfect. Made 285kw, and ridiculously punchy. There is no such thing as "too much turbo" with the 7670 when it is as responsive as that. I'd expect similar boost threshold on an RB25. I've sort of described it to people as GTX35 power for GTX2867 response.

Agreed. You can't go past a 7670 for your Sr20, however, make sure you go twin scroll, and use small cams (256 or 260 max). If you want to keep cost down, go the twin scroll internal gate version. The only other thing is to factor in turbo shaft speed sensor (and ecu that can read it). EFRs are very sensitive to overspinning and will suffer catastrophic failure operating outside recommended max range. For example, max recommended for 7670 is 140,000rpm. This equates to around 30psi on my car. Might be slightly more on a 2L.

Yeah, engine is stroked, plus it might have some head work... However, spool on a standard 2L 4G63 isn't that far behind.

Hey Mick, Yeah 9:5:1. Kelford 272 Yours will be epic with Mivec

I can't remember if I posted my E85 results. Anyway, here it is, just to echo the praise for the EFRs: 7670 T4 1.05 on my Evo V. ~250kw at 4000rpm... 670nm of torque at a bit over 4000rpm. It goes ok haha

Hey man, it's T4 twin external gates. While the plumbing is a nightmare, I didn't want to have to deal with boost control issues

For anyone interested, here is my 7670 dyno graph. Car is an Evo V. As you can see, it's fairly responsive. Not pushing it at all on 98, only 20 psi.

Here are the results on only 20 psi, pump 98... Specs are above, but to summarise 2.3L, 272 cams, EFR7670 T4 TS E85 tune to come. Car is an animal down low

Will be very interested to see how it goes Mick. My 7670 setup should have been finished months ago, but have had issues with my fabricator. Good choice on the turbo though!

Will keep you updated Fab work is being done now. Running clamps on intercooler piping, the whole works. I will lean on the 7670 hard, but need to be careful of overspinning. So I doubt it will see more than 30psi. Not sure if it will make 400awkw, but would be pretty happy if I can get 30psi by 3500. I reckon it will be closer to 3900, but we will see. I'm only interested in area under the curve as I get older haha

I'm selling a precision 6466 with JMF 1.5" runner ceramic coated manifold and turbosmart 45mm pro gate. Good for comfortable 500kw. Downsizing for response to BW EFR7670, twin scroll, twin gates. Any predictions for boost threshold on a 2.3 stroker, +1mm intake and exhaust valves and kelford 280s? I know the cams aren't ideal for response but couldn't be bothered changing them.

I concur, just wondered if anyone sells them commercially

Any idea where to get the 12-14mm mounting bolt sleeves?

I'll take them mate, PM sent

Pecky's mate. Pricey though, and one of those workshops that are too busy for their own good

Hey mate, please put me down for a set of Bride Low Max Gias 2 black, standard type, kevlar. I'm up in Darwin, I hope freight won't be exorbitant.

Whoops, it was late haha

I'm fixing it now, but I think the best im ever likely to achieve is desired boost by 4000rpm. Don't get me wrong, I like my current setup, but my car is currently apart getting various work done to it and I'm in a position where I could easily change turbo now if I wanted to, or if an opportunity arose. You're probably right that the changeover cost may not be worth it, but equally likely is potential performace from the 7170 that a gtx3071 would dream of, if it wasnt in fact an unanimate object. You don't work for Full Race do you?

Thanks for the suggestion. However, like GtScotT, I really like the look of the 7170. Also, my .63 gtx3071 hit 20psi @ 4200, with a giant intercooler pipe leak.

Amen good Sir

I'm affraid the explanation is fairly simple. My existing exhaust manifold is made for EWG, deliberately, because I think its neater and provides better boost control. All I'm saying is that I'd readily upgrade if the option of a bolt on affair were available

I'm with you. T3 single scroll EW, in a size that my SR20 can spool. You'd have an instant customer.

It's probably because they are ridiculously busy. Probably because they're pretty good.

You sure about that? Last time I was there they had an r32 there for a tune, and they're touching my S15...