Precision Billet Turbo discussion

That turbo spools identical to mine, its as laggy as I would go on a street setup. I'm looking forward to seeing the power you can get out of that 62 62. We have put a few on some 240s around here and they are really imrpessive at 20+psi. Car looks and sounds great flawlez.

[quote]RedBeauty84ZX wrote: Could not do it. 3900 ftl unless it turns 8-9k. Well roll racing NM.

For those of you seeing the powerband as laggy. The tune on my car is NOT even close to done. Its merely a safe driveable tune. I have a bad TPS which is causing a very rich condition under WOT and it completely floods out if I try to maintain acceleration into the next gear as it keeps dumping fuel between shifts. The timing maps are nowhere near optimized especially in the midrange as again, I simply haven't had the time or conditions to properly tune the car. I don't even have a clutch that can hold the power I'm making currently which really isn't much. Maybe 400 RWHP. The other factors to consider are:

7.8:1 motor
2.5" piping + huge ass intercooler
274 Schneider cams
not optimized timing map
not optimized fuel map
gain has lots of headroom on EBC
And pulls were done in 2nd gear

I'll shoot more video later on as I slowly work through and fix the things I need to to get the car where it needs to be.

What ecu are you running?

Nice clips, I dont think the lag is all that bad everything considered.

Stock heads/internals? If you can push the usable powerband over 7,000rpm, getting full boost by 4,000rpm is still real nice!

I agree.

Heads have mild port. Schneider 274 cams, 110 lb springs. Stock bottom end. Once this thing is all ironed out and I finalize the tune, I'm confident I'll see boost 200-300 RPM's sooner and my powerband will reach as far as 6800 RPM's. This should net to nearly a 3000 RPM range of power which is quite good.

any reason why this is a particular factor?

wouldn't the large intercooler just get heat soaked less and the small diameter piping require less of a volume to be pressurized?

I'll be running much the same soon and I was just wondering…

[quote]Careless wrote: The larger intercooler has more total air volume and surface area to be pressurized. Therefore the turbo must work that much harder to overcome the increase in total atmospheric volume which in turn requires that much more air flow from the engine to further spool the turbo. This isn't a huge contributing factor, but it is worth mentioning as every little change adds up.

A lot of people here may look at the spool as being quite laggy in comparison to say a stock or bolt on turbo Z31. The reality is, when you add any intercooler setup to the stock configuration you're going to dramatically increase lag as it was non existent before. Comparing a non intercooled car with the same car intercooled is comparing apples and oranges.

This must be the case, because I don't think it's very laggy at all, I like the way it responds in the video.

I think my comment may have come off wrong and I apologize. Just trying to get an idea of if I was reading the gage right.

This powerband looks great for what you use the car for, excellent choice. The boost rise (from threshold to full) is extremely fast; that looks like a lot of fun. Thanks for posting the videos, very helpful.

Especially when the factory charge pipe is crazy short to begin with…

[quote]roastin300 wrote: Sounds like your static compression ratio is too high if the ignition has to be retarded that much. In which case of course a higher octane fuel will improve the situation.

I understand that, It's a no brainer. What I'm wondering mostly is how did the intercooler setup differ from your last turbo and did it make that much of a noticeable difference to make mention of it as a strong contributing factor?

For a second, it sounded like you mentioned 2.5 inch piping as though to say you should be running something smaller, as well as a smaller intercooler and you regret this setup's induced lag.

What is your guestimated total piping length anyway, and which IC?

Its a little laggy for my taste. I am now considering a HX40 with a 16cm housing and a quick spool valve. I thought it would spool much faster than that. I am sticking with stock cams and heads for now so I need a faster spooling turbo because the stock heads dont flow much over 6500rpm's.

[quote]Careless wrote: FlawleZs old intercooler setup which was I believe was two and a 1/4 inch piping, and a MKIV intercooler. This intercooler setup worked ok, but got heat soaked easy. He made 360WHP/480WTQ with this intercooler setup and his old T3/T4.




His new intercooler setup, two and a 1/2 inch piping, much bigger intercooler:







My brothers last turbo was a T3/T4, 50 Trim compressor with Clipped T3 Turbine Wheel and .63 A/R , his new Precision Turbo Billet 6262 is a noticably larger turbo capable of significantly more power. To put it into perspective his billet 6262 spools just as quick as his T3/T4. His old setup was on bone stock heads and a smaller intercooler/piping setup. With his schneider cams, bigger intercooler and bigger piping he has shifted his powerband roughly 1000RPMs higher in the RPM range then it was before, if he had kept his old setup but just added the 6262 it would have spooled QUICKER then the smaller 50 trim 6262.

With his new setup the pull is much better, the power band has improved and the power dosnt fall off in the high RPMs like it did with the stock heads and T3/T4.

Also were planning on getting a couple more vids this time of pulls in 3rd gear, should show the turbo reaching full boost a little lower in the RPM range.

Hope that puts it into perspective.