Definetly coming off as a *****

 

KevPSR

I'm guessing in this vid the Evo was on race gas and maybe a shot.

http://www.srvidz.com/SRvidz_evodyno.wmv

Does this guy have any runs on pump gas taped?

 

Race gas, but no nitrous..I don't have any runs of Chris on pump gas on film though

 

Is his spool up the close on pump gas as it was on race gas?

 

Here is another data point. Throw this in your graph Nate. This is from my buddies car on pump gas that we finished up the Friday before the Shootout.

2500 -.376
2777 -.394
3007 .099
3250 .466
3519 .740
3769 1.894
4003 3.121
4277 4.000
4511 6.728
4746 8.761
5019 14.328
5289 18.265
5515 20.992
5769 21.816
6089 22.294
6265 22.714
6511 23.448
6750 23.337
7031 23.703
7292 23.520
7500 23.082
7781 23.136
8000 23.960

AEM EMS with an ************* base map that I've massaged a little.
Stock short block w/ ARP studs.
HKS 280's w/ springs & retainers
Shearer T3 kit with 61mm S cover. Stage 5 .82 hotside.
Buschur Racing 3" exhaust
880 injectors with Walbro pump
Buschur Racing Intercooler w/ 3" up pipe

The car went a high 117mph trap on pump gas last night. No ET though as I rolled through the beams, stabbed the clutch back in, and relaunched the heep. Went 13.4 goofing up and relaunching. It should go a little better on Tuesday when we revisit the track.

 

Ron,

Is that 2nd gear? If so, wow..that looks great. I ran my evo yesterday for 2 pumpgas passes at 22psi. 14.1 @ 107 with a 2.9 60' and 13.1 @ 111 with 2.0. That wa launching at 5800rpm and 6700rpm. I think something is up with my turbo/setup as the boost response is so pathetic, the only way I can get the car to llauch worth a damn without bogging is 9000rpm fuelcut, 7500rpm ign cut, 7300rpm ign retard. That ends up retarding the timng like crazy, huge backfires..and it makes like 13psi.

Think im going to pull the turbo and put a GT30 on or something. Car is not really raceable like this, not realistic to launch at 7300rpm and abuse the clutch.

 

That was 3rd gear getting into around 2400-2500. I've only made two passes in an EVO so far and it's nothing like launching a talon. I got up there and did my usual thing which would get any similarly prepped talon put of the hole like a banshee, and it friggin bogged. Definetely need to drive these cars like an "animal".

 

The thing of it is you guys are running insane amounts of boost. If I get a 35r, Buschur's, I only plan on running about 21 psi with a reflash and on 93/94 octane. So my lag shouldn't be as bad.

 

Do NOT buy a GT35R if you only plan on running 21 psi! Stick with the bolt on 20G (best choice) or if you are stuck on a ball bearing setup go with the GT30R.

Also, spool up is slower when you run lower boost levels. When your target boost is 20 psi the wastegate starts to open at around 16 psi and slows the spool up way down. When running 25 psi the wastegate doesn't even think about opening until you are past 20 psi.

Keith

 

Thanks for the advice! But I hear the 20G has serious surge.

 

Concerning the video on the dyno. The reason the turbo is spooling slowly is because he is rolling from 3rd,4th gear. He needs to start from a lower gear such as first or second.

 

On page 12 we finally get the answer we were looking for!

Does anybody want to take this one? I seriously don't know where to start.

 

Well it makes sense. Imagine cruising the interstate in fifth gear at say 65mph, then try to gun it. Takes a while doesn't it? Take a look at the Top Gear video where they race the FQ400 vs. a 1.6liter something or other. They start from a 30mph roll in fifth gear. The guy in the Evo floors it and the little car is pulling away. It takes almost a whole mile for the Evo to catch up and pass.

 

Well, you are talking about spoolup/power output rising agaist actual TIME. This thread is regarding boost pressure vs engine RPM. completely different.

boost pressure/rpm spoolup is BEST in the highest gear becuase there is the most load on the engine. Go back and look at some of the graphs that show faster spoolup in higher gears.

When running a car on the dyno, you do not run the car wot through lower gears and shift into the next gear. That's a nice reciepe for jumping the car off the rollers. Get the car up to speed gently into 3rd or 4th gear and go wot before or right at the rpm where the turbo will start to make appriciable boost and hold it wot till redline.

 

All stock based turbo's (stock 03, stock 05, TME, WR, and 20G) have part throttle surge under certain conditions.

Take your car and run it up to about 4,500 to 5,500 RPM in 3rd gear at WOT, then back off to half throttle (still in boost, but not WOT) and try holding it there and you will get surging.

I'm not joking, go try it befor you decide not to get a turbo like the WR or the 20G.

Keith