A fun but disappointing first trip to the track

[leemozoid]

Originally Posted by crazydave

Nope, that will help with consistency if want to help bracket race the car. You need to figure out where all your HP went and the only real way to do that is data log. You can see where your timing, IAT2s are relative to your position on the track.

I would also advise against running the car if you are low/out of meth. If you tune is aggressive and depends on it and it runs out it can be a very bad day for your engine.

I was running a 50/50 mix of E85 and E100. Even absent the methanol there was enough alcohol to prevent detonation. I'm not going to track the car again until the system is back up to 100% but in the meantime I need to figure out the issue with it spinning at the line despite the drag radials. Lower psi seems to be a key (18-20?) and possibly better burn outs. Other than that it's flash vs. torque load the converter and what rpm to launch at. I need lots of practice rolling into the throttle to make sure the tires hook. That's a given. I'll put the hp issue on the tuner to fix.

[STUNNAH]

Originally Posted by leemozoid

I need lots of practice rolling into the throttle to make sure the tires hook. That's a given.

You answered your question...

[Can'tHave2MuchHP]

Try to run in less than 1000 DA if possible...

Get a better tire (18" NT05Rs suck in my experience with a C7Z). Get some Mickey Thompson or Hoosiers. You'll launch so hard your seat mounts might break LOL.

No 2000 RPM launch, I agree with Ted. That is hurting you more than helping you. The quickest times that I've seen on Cam/Bolt on A6 ZL1s is roll into the throttle through first gear, should be WOT by the end of first/beginning of 2nd gear. I mean heck even Nick was getting 10.2-10.5 at 660 RWHP just rolling into it on 20" NT05Rs. He went slower when he "brake boosted" it. As soon as you spin and get out of it, you might as well cruise the rest of the pass, no point in subjecting the drivetrain to the abuse.

Also, log them IATs and make sure something isn't wrong. Running full E85 and Meth should keep things very cool and certainly very manageable for just 1/4 mile runs. Your pulley setup is very manageable too...if it's getting hot enough to be pulling serious power and running 12s/high 11s even after fixing/helping the other issues, then you have problems.

[leemozoid]

Originally Posted by Can'tHave2MuchHP

Try to run in less than 1000 DA if possible...

Get a better tire (18" NT05Rs suck in my experience with a C7Z). Get some Mickey Thompson or Hoosiers. You'll launch so hard your seat mounts might break LOL.

No 2000 RPM launch, I agree with Ted. That is hurting you more than helping you. The quickest times that I've seen on Cam/Bolt on A6 ZL1s is roll into the throttle through first gear, should be WOT by the end of first/beginning of 2nd gear. I mean heck even Nick was getting 10.2-10.5 at 660 RWHP just rolling into it on 20" NT05Rs. He went slower when he "brake boosted" it. As soon as you spin and get out of it, you might as well cruise the rest of the pass, no point in subjecting the drivetrain to the abuse.

Also, log them IATs and make sure something isn't wrong. Running full E85 and Meth should keep things very cool and certainly very manageable for just 1/4 mile runs. Your pulley setup is very manageable too...if it's getting hot enough to be pulling serious power and running 12s/high 11s even after fixing/helping the other issues, then you have problems.

1000 DA?

[EvilZL1]

Lower tire pressure for sure

[acammer]

Originally Posted by leemozoid

1000 DA?

Density Altitude. You have some reading to do. Short version, the ambient temperature, barometric pressure, and humidity have a lot to do with how much oxygen is in each "gulp" of air you engine ingests. The lower the DA, the more oxygen your engine can ingest and the more power it can make.

1500' of extra DA can easily knock two tenths and two mph off my bolt on car.
Boosted cars are less impacted than NA cars by Density Altitude, but still will see a swing in MPH and ET based on the DA.

These guys are on point with the tire pressure - you're gonna need to be sub 20psi to get any work out of the NT05Rs. I have that tire (305/45/18) on my bolt on car, and it barely works at the 400rwhp level out on the street, so I would imagine with your power level it's not gonna prove to be your best option. Doesn't mean it can't work, but there are better options. That tire won't take the hard flashes, you're gonna have to roll it on.

I still think you need to get the car running right before you get too worried about making it hook. Once it's making the power it should, it's gonna be wildly different anyhow - get it right, then figure it out.

[Can'tHave2MuchHP]

Originally Posted by acammer

Density Altitude. You have some reading to do. Short version, the ambient temperature, barometric pressure, and humidity have a lot to do with how much oxygen is in each "gulp" of air you engine ingests. The lower the DA, the more oxygen your engine can ingest and the more power it can make.

1500' of extra DA can easily knock two tenths and two mph off my bolt on car.
Boosted cars are less impacted than NA cars by Density Altitude, but still will see a swing in MPH and ET based on the DA.

These guys are on point with the tire pressure - you're gonna need to be sub 20psi to get any work out of the NT05Rs. I have that tire (305/45/18) on my bolt on car, and it barely works at the 400rwhp level out on the street, so I would imagine with your power level it's not gonna prove to be your best option. Doesn't mean it can't work, but there are better options. That tire won't take the hard flashes, you're gonna have to roll it on.

I still think you need to get the car running right before you get too worried about making it hook. Once it's making the power it should, it's gonna be wildly different anyhow - get it right, then figure it out.

Solid info.

[ODB Racing]

I agree the tire pressure needs to be lowered and you need a better tire for track use. A M/T is superior to the Nitto. I run 17-18psi in my M/T tires.

Try leaving at 1000-1200 rpm. With a looser converter your rpm is rising much quicker than with a stock converter and can cause tire spin because you don't have a drag suspension. I build converters and I'm not convinced our cars need one after doing some logging. With the older N/A cars and 4 speed auto's you will see a .6-.7 gain in just a converter swap because the car gets up into the rpm range very quickly. With these 6 spd auto's, your at the top of 1st gear at 6000 rpm by close to the 60' mark so getting it there even quicker will require a really good tire and suspension upgrades. There may be .2 gain in et with a converter but the car will need a serious drag tire on it to see the advantage.

[leemozoid]

Originally Posted by ODB Racing

I agree the tire pressure needs to be lowered and you need a better tire for track use. A M/T is superior to the Nitto. I run 17-18psi in my M/T tires.

Try leaving at 1000-1200 rpm. With a looser converter your rpm is rising much quicker than with a stock converter and can cause tire spin because you don't have a drag suspension. I build converters and I'm not convinced our cars need one after doing some logging. With the older N/A cars and 4 speed auto's you will see a .6-.7 gain in just a converter swap because the car gets up into the rpm range very quickly. With these 6 spd auto's, your at the top of 1st gear at 6000 rpm by close to the 60' mark so getting it there even quicker will require a really good tire and suspension upgrades. There may be .2 gain in et with a converter but the car will need a serious drag tire on it to see the advantage.

This is clearly one area where the most gain can be had. We don't need hp. We need to make efficient use of what we have through driver practice, better tire and better suspension. I am extremely grateful for all of the input so far. Now I'd like to hear about what I can do in this regard. Keep in mind this is a convertible, and will always weigh a lot. I'm not going to gut it just to make it a drag car. It's still a daily too.

[leemozoid]

Bump for suspension input.

[leemozoid]

Originally Posted by leemozoid

Bump for suspension input.

Silence is deafening. Nobody?

[JANNETTYRACING]

Originally Posted by leemozoid

Bump for suspension input.

Originally Posted by leemozoid

Silence is deafening. Nobody?

Suspension is not your problem.

[WoodBoss]

I would suggest once your car is running good with your meth install to drop the tire pressure to 16 psi and get in a good burnout. Hold your brakes on at the tree and keep it about 1200 rpm or so. If track prep is good you should be able to launch pretty hard. See how other cars are launching to get and idea of how the track prep is. If track prep is bad it will be hard to hook. At your power level your car should be in the 10s when everything is working right.

[frankwjr]

IF you REALLY want to spend sum $$$ since the rear suspension is already pretty stout...you could add sum chassis stiffening braces(BMR, Hotchkis, etc.)...what I really liked was when I changed out my motor mounts for Prothane..made everything feel tighter, shifts more precise and now I can feel the cylinders firing away...awesome!


good luck and FYI don't be afraid to HAMMER the crap out of it...lol.


peace.