Street tuning

[asshanson]

Just a few quick questions, looking for opinions, your experiences, etc.

First off, my old setup was a t28, fmic, 2.5->3" exhaust, and 650cc injectors. I ran about 18 lbs of boost that faded to 15 or 16 at redline. I usually flowed about max 1680 hz for air (at 5500 rpm, it faded bad up top), and made 220awhp on DynoDynamics. Corrections on the AFC were -32%.

I just changed to my super 20g, and I would flow almost 1400 hz running spring pressure at 9 lbs. I upped it to 15 psi and it went to nearly 1700 hz, now I upped it to a spike of 22 psi and settles to 19 psi, flows 1870 hz on one run. Timing is good, 18-22 degrees until redline. Corrections are about -25 to -28% now.

I'm sort of concerned though because I expected a lot more gains. Do the results seem reasonable? Who else runs a 20g, do you have similar airflow? How much power do you make at similar settings? Just trying to get an idea of what to expect at the dyno day.

[1ViciousGSX]

I've always looked at lb/min of air flow as a better indicator of power potential. Remember, engines are nothing more than air pumps, more in/more out = more power as long as the tune is good.

[scheides]

You may not fully realize the full power potential of that turbo until you get cams. However, I'm sure as you drive it around a little more you'll realize how much harder it pulls up top than your T28 ever could. Its not like you went from a T25 to a 20G, the step from a T28 to a 20G is not super huge.

Also, once you get it on the dyno, you may see spots in the tune that you can lean out for more power. When I had that turbo, I did a street tune as best I could. I put it on RS' dyno and put down like 239whp@20psi. I ended up turning down the boost to (it was knocking here and there) and tweaking the crap out of the tune and making 278whp@17psi.

So, cams and dsmlink should be next on your list ;)

[Kracka]

Cams should definitely be your next power mod, but first and foremost get those boost leaks fixed. Come over to Scheides' house on Saturday and we'll take care of those leaks and get some new plugs in your car since your current ones were never gapped properly and are over a year old. We can go tweak the tune again once those things are done.

[A//// Guy]

Dyno tuning ftw, and yea dsmlink would be ideal.

[scheides]

Cams should definitely be your next power mod, but first and foremost get those boost leaks fixed. Come over to Scheides' house on Saturday and we'll take care of those leaks and get some new plugs in your car since your current ones were never gapped properly and are over a year old. We can go tweak the tune again once those things are done.

Ahh yea, I guess I forgot to mention this, but your car needs to be in good shape to make good power. Keep fresh plugs in, your existing ones are probably dirty as hell from driving around super rich all weekend. Let's get those boost leaks taken care of as well, you will be hurting power if you don't take care of the basics. Swing by napa and get some BPR7ES NKG's and we'll get ya rockin.

[Kracka]

If you can't find them at Napa, Checker should also have them, and if not just go to a motorcycle/jetski shop. Actually, I'm pretty sure MAP stocks them too.

[Kracka]

Oh yeah, you need a 3" downpipe/testpipe too.

[A//// Guy]

Eh I dont think much gains would be had at all with a 3" versus a 2.5." Better spool and maybe a couple horses, but nothing major.

An e85 swap would gain a lot more power, and a good dyno tune would probably be the best bet over street tuning.

[Kracka]

With cams you're going to be trying to shove a lot of air through a 2.5" pipe. I'd do cams first, but keep it on your list. E85 may not be a good idea since you drive to Iowa a lot; I recall someone mentioning on the cruise this weekend that E85 can be tough to find down there at times. Definitely check into that before doing it.