What's wrong with this? Slow E.T. and trap speed

[Brezick]

With a PD blower, you are going to be in boost right away.

 

[fdjizm]

So he already knew what was wrong and fixed it just like that?

 

[Swarzkopf]

Also, nobody else goes anywhere here flooring it in 3rd at 2500 rpm, not sure what you expected from that. lol

Huh? I leave my 5R55 in 3rd and 4th alot when I want to have some fun on the highway- even stomping it at 2500, it takes off pretty good. At 3000, it rips hard. And I have a slow winding Paxton, not an insta-boost M90 like skwerl does.

Edit: Missed this:

repeated my earlier test of accelerating from 2500rpm in third gear and it threw me back in the seat.

That's exactly what I'd expect from a roots blower car.

 

[skwerl]

What's a PD blower? And with my original tune the boost would come on over 3000rpm. He definitely lowered the threshold all the way down to where now the slightest touch of the pedal will begin drawing a little boost.

 

[Swarzkopf]

What's a PD blower? And with my original tune the boost would come on over 3000rpm. He definitely lowered the threshold all the way down to where now the slightest touch of the pedal will begin drawing a little boost.

"PD" is "positive displacement"- this includes roots (Eatons, ie M90, TVS) and twin screw blowers (Lysholms, like the Whipple and Kenne Bell). They make power fast and hard compared to centrifugal blowers (like Paxtons, Vortechs, etc).

Your tuner probably adjusted your drive by wire settings to allow the throttle blade to open faster, and MORE, at lower throttle pedal positions. Since your boost bypass valve is vacuum activated, the increased throttle open angle at lower RPM is resulting in vacuum dissappearing faster and you getting into boost faster.

 

[Blackbird1084]

Sweet deal man. Can't wait to see some improved et's.

 

[11secLX]

your graph really flattens out the hp at 5200. I'd short shift it. If the car isn't making significant power beyond a certain rpm then you should be pulling the next gear to get back into the meat of the powerband where it accelerates the hardest. Powershift at 5200-5300 and see what happens.

...for comparison my car is a stock version of yours and runs consistent 13.2s at a little more than 104mph. That's on a 275/40R17 MT ET street drag radial. I launch at 5000rpms and powershift each gear near redline. I can do that 'cause it accelerates hard to redline. Oh yeah, I have to shift into fourth.

 

[skwerl]

I think it's pretty obvious that he had my original tune dialed back a little bit. Maybe I didn't impress him much as an operator at first, maybe he was skeptical of my car with the used blower installed by a mechanic that he didn't know. But he's got a lot more fuel going through now. My in town mileage has dropped from 15 to less than 13 according to the fuel calculator in the dash display. I've got about 35-40 miles on the new tune already. It doesn't even feel like the same car, it's fun to drive again.

 

[11secLX]

well either you can dyno it again and see how the power curve is and adjust your shifts based on what it shows or mess around with shifting points at the track. But you were definitely wasting valuable time by waiting to shift at 6000rpms.

 

[Racingtheburg]

The DR's he bought are perfect for his power level. The 60 foot needs to change. You have almost a .5 a sec to improve on if not more. You should be shifting around 6200 or so not bouncing off rev limiter this will kill your MPH and ET.

What is your regimen at the track?

Give us a walk through when you start up your car heading to the water box until you pass the 1320 line.

We can guess all day or we can state the facts and try one item at a time before buying things to get a lower ET....or you can keep buying stuff and run worse or about the same.

 

[skwerl]

With the new tune I got yesterday I'll be able to shift at 6200 now. Before the rev limiter was set at 6250 so I had to shift near 6K in order not to hit it. Now it's at 6500.

Chris, I'll answer your other question after Friday night. Let me see if I can do a little better with the tune fixed, then I'll have a better idea of where my driving faults are.

 

[Racingtheburg]

Sounds good man let us now what your are doing at the track to best help you.

 

[Xporter]

Good luck on friday. The car definately seemed like it should've had alot more in it. I watched it going down the track and it seemed like the power just wasn't there.

P.S. The sausage patties were good!

 

[skwerl]

Hah! Glad you enjoyed them. I wasn't hungry, just bummed because of how slow the car was and ready to find someplace air conditioned.

 

[iRoush]

Glad you can be nice to some people....

Good luck.

 

[joshwfl]

Glad you can be nice to some people....

Good luck.

Agreed

 

[RetroGT2006]

Glad you can be nice to some people....

Good luck.

Agreed

+1..

 

[blue streak]

I am interested in what you run tomorrow. Also, I would go with MT 275/50/15s. I have a 4.10 gear and the same power level but NA. Im on stock 235 17s and I average 89-91mph with a 2.0 60ft.

 

[Redfire_WNL]

Im saying, Agreed!

 

[iRoush]

I am interested in what you run tomorrow. Also, I would go with MT 275/50/15s. I have a 4.10 gear and the same power level but NA. Im on stock 235 17s and I average 89-91mph with a 2.0 60ft.

Those are KILLING you bro. Throw those MTs on there and it will feel like a new car!

My chick's '11 V6 traps at 101-103 with a 13.7 on 20's. So, it's the 235's killing yours. As for the OP, we already told him he needs to lower the PSI in the tires. What good does lowering to 20psi do? Once you do a burnout, you're back up to 22+psi in the tires. When I ran 275/45/18 555R's, I went 15psi in my tires. With that, I was cutting 1.6-1.7 all day.