MetallicaMatt

iTrader: (19)

going to the track in a week for test 'n' tune

I finally have my 2-step from LPE on the car. On the dyno, the car makes the most torque right around 4800 rpms.

I'm running M/T ET streets, 28x11.5's


So...what'd be a good rpm and psi to start out at?

I'm afraid to go to low on the psi, for the car walking at the top end of the track?

BTW my rims are screwed, so i wont be spinning the tires on the rims this time

LS1Formulation

iTrader: (13)

Honestly, each combination will be different - I have been experimenting with my new combo and I dropped .4 changing pressures and launch RPM. I run ET Street radials tho... so far 16 PSI and a 6200 RPM launch have got me my quickest time. I'd start out at 20 PSI and a 5500 RPM launch and work down on the pressure in 2 lb. increments and work up on the RPM in 200 RPM increments. Eventually you will find that sweet spot that gives you the best 60' time.

MetallicaMatt

iTrader: (19)

i figured to start, launch around 4400-4600 rpms, since i make peak torque at 4800, so i drop down a bit on power when i launch but still have more power band to go before shifting?

plus, i'm not sure how much these tires are going to walk at the top end at lets say, 18 and 16psi if i get that far?

jmm98LS1

iTrader: (28)

Are you running tubes? I run my et streets (no tubes) at 15psi and launch at 6500-6700rpm. It skates around on the big end more than a radial does, but it's not bad at all. I'd prob start out around 17-18psi and work your way down in small increments.

MetallicaMatt

iTrader: (19)

No tubes either. They hold air REALLY well, i'm surprised, my Bogart rims are nice.

define "not bad at all"? lol I'm sure i'll let off, instead of driving through it if it starts to skate

jmm98LS1

iTrader: (28)

lol It won't scare ya enough to let off. Mine doesn't skate around anymore at 130mph at the track than it does at 80 on the highway.

MetallicaMatt

iTrader: (19)

so do you still believe i should start higher than 4500rpms? since mine isn't built like your motor, and i'm starting my shake downs and will need to adjust my suspension i'm sure. I'm having it recorded so I can watch it afterwards and tweak it

jmm98LS1

iTrader: (28)

Every car will be different....I started at about 4500 for my shakedown runs with this motor. Mine bogs hard enough to smack the air dam on the track at anything under 6500rpm......had a few consecutive embarrassing launches that night lol. The key with clutch cars is something has to slip a lil (either the tires or the clutch) or it's gonna bog. My spec 3 clutch will die if I slip it, so I dump the clutch really high and get a few revolutions on the tires to get me going. It's a fine line and takes looooots of practice! I'm still not very good yet, haven't cut better than 1.6x 60' so far.

MetallicaMatt

iTrader: (19)

yeah my Spec 5 is either on or off, so I rather just slip the tires, but I wont know at what point, i'll either slip the tires, or just blow them off!

I have my QA1's set at 5 upfront and 7 outback, does that seem right? Or am I going the wrong way?

maybe 5 upfront, 2 outback?

jmm98LS1

iTrader: (28)

I run my strange SA's at 2 in the front and 5 in the back. You generally want it stiff in the rear, looser up front.

MetallicaMatt

iTrader: (19)

thank you sir

trigger1

iTrader: (28)

Back when I messed with six speed stuff, I would launch at 6400rpm with a TR224 car that made just under 400hp. With ET streets on the car I would start with 16.5 psi cold in the tires and adjust from there. I sometimes could get away with 18psi warm if the track was holding nice. I like the idea of running as much air in the tire that you can get away with.

Run the rear of the car as stiff as the track will allow. Once you accomplish that you can fine tune with your front suspension.

MetallicaMatt

iTrader: (19)

Since i'm super **** about triple checking everything...I'm assuming on my QA1's, all the way "-" is 0? Then 12 clicks "+" will be 12?

jmm98LS1

iTrader: (28)

Should be. On mine clockwise = stiffer, counterclockwise = looser.