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

[TexasKyle]

So you think I should stay with the taller tire and stay in third gear?

No. 26" will do good. If you cross the line at 4500 in 4th, then you need a shorter tire. Also, that tall tire is killing you off the line. I ran a 28" M&H for a long time.

I don't agree that your trap speed is all that low. I only trap 114 @11.8 in the 1/4 mile. That's 1.8 seconds faster than you, but only 7mph faster.

If the car is a dog unless you go WOT, then I would say your tune is not optimized. If the tuner didnt get that part of the tune right, it's fair to say he didn't get the rest of the tune right.

Lastly, practice. Get some tires that will hook, and practice your launches. That's gonna be a huge factor for you. Drop a 1/10 in your 60ft, and pick up 2/10 in the 1/4 (roughly) Get down to a 1.7 60ft and you will feel alot better about how you're running.

 

[Brezick]

Yeah, if you are already getting into 4th, the shorter tire will do you good. In my example, I was crossing the line in third at 6k, almost perfect, but with the shorter tire, it screwed me by causing a shift to 4th.

 

[fdjizm]

I don't agree that your trap speed is all that low.

He has 385rwhp... that trap speed is definitely low.
I am trapping higher with 320rwhp, that doesn't even make sense.

 

[Swarzkopf]

Yes. His trap speed is horribly low. I likely make near the same RWHP (maybe just a little more) and I'm trapping 7 MPH higher, and I consider my trap speed bad. 105 traps from a boosted 3V is terrible.

A 2.0 60' is bad, but it alone doesn't account for how terribly bad his ET is and has very little impact on his poor MPH. Hell, I managed 12.40 with 2.0 60s.

It could be bad shifting combined with heat soak- I hot lapped my car the track a few weeks ago, and my MPH went from 112 on the first pass to 108 on the second one! Heat soak is a bitch, so it's definitely possible.

Nail the shifts, run the car when it's cooled off, and I bet the traps come back up.

 

[Brezick]

I am pulling 11's and only managing a 109 trap speed...(of course I know my tune is causing it)

 

[skwerl]

I thoroughly appreciate all the honest feedback, guys. Sounds like my next two steps are to figure out how to raise my redline back to 6500 (the tuner dropped it from 6500 to 6250) and then try again on Friday night. Before I buy new tires I want to try once again on these tires while shifting at higher RPM and crossing in third. And my launches will only get better with practice.

 

[fdjizm]

If you can reload your tune you can change the redline.
before you load the tune it asks you if you want to change options, select yes.
you can use the left and right arrows an scroll through the options till you see rev limiter (unless the tuner locked those options out)

 

[skwerl]

How do I get to the screen to 'load the tune'? And how do I identify which tune?

 

[fdjizm]

first what kind of tuner do you have?
SCT?

 

[benjytps]

datalog it, see where your timing is actually at and see if your IAT's are getting high and pulling timing.

 

[skwerl]

Datalogging is not possible until I can find somebody who knows how to use the SCT tuner. I just looked at the instruction manual included on the CD in the package and it wasn't very detailed. I'm getting ready to go out and plug this thing into the car and see if I can figure anything out. Hopefully I don't end up disabling my car since the guy who tuned it is so damn hard to get hold of.

 

[fdjizm]

plug in tuner.
go to load tune.
go to custom tune.
you should see a list of 3 items, one will be your custom tune, don't know what it's called.
load tune.
it asks you to change options, press yes, see what you have to scroll through.

 

[skwerl]

OK, I'm back. The good news is that I successfully changed the rev limiter. The bad news is that my engine's low end performance is now even worse than before. At 2500rpm in third gear I can floor the pedal and the car barely moves. If I hold it floored while the RPMs gradually creep up, the boost begins to kick in above 3500 and at 4K the car snaps forward. It was noticeable before but much worse now. I checked for codes and just the P1000 (which has been there for months and won't clear).

Looks like I'm back to getting hold of my tuner guy. I don't want to mess with the tune any more until I speak with him.

edit: My tuner's phone went to voice mail saying he's out of town until the end of the month and do not leave a message. Now I'm getting a little bit upset.

 

[fdjizm]

Did you let it relearn the idle?

 

[skwerl]

Huh? Relearn idle what?

 

[Vapour Trails]

At 2500rpm in third gear I can floor the pedal and the car barely moves. If I hold it floored while the RPMs gradually creep up, the boost begins to kick in above 3500 and at 4K the car snaps forward

That's what I would expect to happen when using 3rd gear from a low speed (out of power band, poor torque multiplication).

Mostly I think you just need a lot more practice, you are leaving really slowly. What rpm are you shifting at?

The P1000 code shouldn't have any affect on the way the car performs.

 

[fdjizm]

Huh? Relearn idle what?

After you load the tune you have to let the car idle for two minutes, then two minutes with the AC on.
Also, nobody else goes anywhere here flooring it in 3rd at 2500 rpm, not sure what you expected from that. lol

 

[skwerl]

Well some more good news! I finally got hold of my tuner guy on the phone and he's going to email me an updated tune. We'll see how that works out and I'll update this thread later.

 

[JeremyH]

To go a different route, plugs?, slipping clutch?

 

[skwerl]

My tuner emailed me an updated tune this afternoon and he went from one extreme to the other. It's definitely better but now the boost gauge starts moving the instant I touch the go pedal, even from an idle. All boost, all the time.
I repeated my earlier test of accelerating from 2500rpm in third gear and it threw me back in the seat. Now I have to be super gentle with the go pedal because 1/4 throttle is the same as flooring it. I'd prefer a happy medium but sometimes people tend to go to extremes. Like when you ask the girl at the drive thru window for a napkin and she hands you a two inch thick stack.

I'll consider the tune 'fixed' for now and live with it like this until I get the pulley swap and retune in October. I'm thinking that my next trip to the track on Friday night will show at least a half second improvement though.

Thanks for letting me rant, guys. I'm looking forward to some more practice on the strip and implementing some of the suggestions posted here.