Wesmaster

I guess that's where he started...not a big deal.

It starts immediately, but at 11 psi it probably didn't reach max boost until 5K or 6K, from looking at the torque curve. I wasn't present at the dyno, and I've only driven the car for one night so I'm not sure when I reaches max boost when starting down low.

[QUOTE][B]Since you "only" made 321 hp at 11 psi (several are making 300 @ 8 psi) and with the torque fall off I am guessing you are running out of the turbo's efficiency range on the upper end.

damcgee

Congratulations! I hope you have MANY trouble free miles!

Is your kit intercooled? Is it "fully tuned" now, or are you planning on changing anything about it?

Wesmaster

Yes, it's intercooled. I don't have any plans for the kit right now. I just want to drive it and have my car for a while. It's been in and out of the shop too much the past 2 years. It's time to stop modifying it and just drive it everywhere.

Wildncrazy

So it sounds like your tuner is playing it safe instead of there being an actual equipment limitation.

Still that drop in power and torque thru the 6-8k range is something that needs to be tuned out. I will bet you find it is a timing issue as I have seen that same look and feel on other cars with timing issues.

The reason I asked about the 4500 rpm starting point is the only time I have ever seen a dyno run start that high is when a manufacturer is trying to cover up an abysmal bottom end. I did not think that was an issue with yours, I just wanted to see how the power line compared to a NA or a SC car. Usually turbo people are quite proud of how quickly they get boost and extra power.

You said the jump from 10-11 showed it got into it's efficiency range, but that doesn't show that at all. The difference between 9 & 10 psi was even greater. The power fall off is one of the easy ways to determine efficiencies and you have a decided power fall off. Whether that is tuning or turbo I don't know because I don't know what turbo you are running. Another way would be to check boosted air temps. They rise quite quickly when you are out of efficiency range.

mbitton

Wes, what type of clutch do you have? Are you running stock? Could be a factor as to why the HP is a little on the low end for a turbo setup.

Wesmaster

One of the issues is the stock ECU, it's always going to limit how smooth our tuning is. We can do some leaning out to smooth the power but my tuner is happy with the a/f ratios how it is right now. We could modify the timing but he feels it's safe where it is. The car had a scan tool plugged into it the whole time it was being dyno'd so any misfiring or issues would have been seen. The timing was being monitored via the scan tool as well.

I forgot to mention that the temperatures were 96-100 degrees outside and that the intake temperatures were 150-160 degrees. The car was not cooled down for any peak runs, these are the runs as they were tuned. I know that a a cooled down SC S2000 can often see 5-10 hp gain, it could be even more with the turbo.

The car runs strong, it's possible that at a later date I might see about smoothing the power delivery at 7.5K, but for now I'm just going to enjoy the car.

Wesmaster

ACT clutch. The power is not low. Almost every out of the box turbo kit dyno that you've seen on S2ki was tuned to 13:1 a/f ratios. Although 13:1 does make more power on a given psi, it is not considered "safe" to most tuners and is definitely not acceptable when you get into higher boost levels. The only dyno I know of to compare mine to would be ChrisD's 320 whp run on 9 psi and race gas. He ran this with only a V-AFC and the stock injectors. This means that with the stock Speedcraft setup he was using the V-AFC to remove fuel. When you take fuel out with the V-AFC you incidently modify your timing (advanced) as well. This is why leaning out the car with a V-AFC produces so much HP. My tuner is much more comfortable making 320 whp on 11 psi with a 11:1/12:1 a/f ratio than making 320 whp on 9 psi with a 13:1 a/f ratio. The car was tuned that way...and that's why it "only" makes 320 whp at 11 psi.

Wesmaster

Thought you guys might be interested in this. All of my boosted dyno numbers (sc and turbo) overlayed.

Wildncrazy

There we go, that shows a good comparison of turbo vs. SC.

I was not trying to belittle your set up or overall power, just saying that as good as it is with a little work it will be better.

Never even thought about you being in Texas also and doing the dyno runs during the extremely hot weather we've been having.

Today's a lot better, at least in Dallas.

Wesmaster

One thing that's interesting to notice is that my turbo kit has always been tuned with conservative a/f ratios. With 7 psi and 12:1 a/f only the low end made more power than the leaner tuned SC. Which is why I wanted to get rid of the FMU so that we could tune better and also why I wanted to add the ignition harness so that we could run more boost. You can see that now the low and AND high and are much better than the SC ever was.