Originally Posted by chilicharger665
I agree with the stock turbo just barely having acceptable spool. I like the AFE, because of the (hopefully) better wastegate and the (hopefully) better spool. The only question we need answered now are power numbers! I hope Klikai is right and the AFE will make power like a 1752, but with OEM compatible fit and better spool. Tork needs to get on it!
I noticed the Goodwin downpipe had that tiny exit, too. I am guessing it is for compatibility with automatic transmissions, because they can only fit a 2.25Ē cross-pipe. I just ordered the System One exhaust from Goodwin and I plan on putting a GESI cat from Vibrant in the stock miata location and running the Tork cat-less downpipe in the future to avoid that bottleneck.
So there's actually a simple solution to fix this. Just cut the bottom flange off right below the Cat and widen the exit. It's honestly not a hard fix, I just didn't want to cut up my downpipe if I'm going to go to a bigger turbo eventually. If the aFe turbo does end up working well and can get me near 250whp on E85, then I'll just cut the downpipe and widen it from 2.25 to 2.5", simple solution and problem solved! I just figured I should retain the resale value of the downpipe in case I sell it, and at current power levels, I doubt the diameter matters too much. If I swap turbo's it'll have to come off again and can be cut/widened.
That said, I do have some details for you guys on the G25-550. I have been told that the turbo has "good usable power at 3000 RPM and hits peak boost at 3600 RPM. It makes peak power up near redline at 7,000 RPM too". It sounds great, but for AutoX, not for me. Would be hilariously fun on the track, I'd imagine it would spool like a classic 911. I thought maybe a GT2554R or a GT2052 may be the answer to this problem, but it sounds like the G series turbos are better designed than the GT turbos, so despite them being smaller, they may not spool much quicker at all, nor would they make big power.
What I honestly want is 275-300whp with stock spool. It seems like it'll be hard to accomplish, but I'm sure we'll get there. Honestly, if the aFe turbo was stuffed it would probably be perfect. I know Tork was working with a manufacturer on a stuffed turbo, but he changed companies designing it and I doubt it'll be done any time soon. I'm also really waiting for them to get their Stage 2 tune finished, it makes amazing power compared to other tunes (see Brett's car), but they still haven't smoothed it out and made sure it's 100% safe for the mass market. I personally would be willing to run it on E85, do some data logging and see if it is or isn't safe, but he doesn't want to send it out and have the potential backlash if there were issues which makes sense.
One thing I did hear, a lot of guys are suggesting swapping a TJet head on our motors, is that something that is possible? From what I've heard that's what tuners in Greece are doing and making big power on the Fiat engines.