Just got back from the track tonight and I am in shock. The last time at the track with F1's I ran a best of 13.00 at 106. Went tonight to try to get a 12 with my ET street and ran a best of 13.31 @ 102.8. The temp tonight was about 10 deg. warmer and the air was on the thick side. I'm sure the lower mph was due to running 16 in vs. 18 in rims. The thing that puzzles me is my 60ft times did not improve at all!! I am still in the 1.90's. I had the air pressure at 20 psi's and when I did my burn out I spun them for a good 30-45 sec before releasing the brake. I made my first pass on the F1's and my time was 13.28 @ 103.5. How is this possible? What did I do wrong? Any help would be much appreciated. Mods are in my sig.

 

Ok, where to start??? Stock stall converter??? If so then stall to 1000rpm and nail it on the 3rd yellow!!! Run those tires @ about 14 -16 psi!!! The burn out should only last about 10 seconds TOPS!!!



Chikin@Charter.net
---------------------
Black '01
Born on 5-3-01
#3603 of 6381
424HP/528ft.lbs @ Normal Temp. w/o N2O
LFP 2600 P.I. Stall Converter
JL Logocaps w/Keychain
JL 3# Lower Pulley
Sean Hyland 2# Upper Pulley
JDM Cold Air
JDM Boost Bypass
JDM/Accufab Throttle Body
JDM Longtubes w/ Silver-Bullet cat-back
JDM Cobra R pump
JDM Eletric Fan
JDM 2” Drop Shackles
PSP 4-Way Autologic Chip ( Tow, Street,Track, N20 )
PSP FactoryTech Valvebody
PSP Deep Tranny Pan
PSP DriveShaftLoop
PSP Truck-Traks
PSP Nitrous Plate
Nitrous Express 50-150 Kit ( Can’t decide which jets to use )
NGK / TR6’s ( .040gap )
Hoosier DOT’s 28 x 10 x 16
NEXT:
Built Shortblock w/Ported Heads
Monster Box Tranny
JDM 166 Blower and 100mm MAF
AND DEFINITELY SOME BIGGER SLICKS

 

Yeah, what Chikin said .

Launch between 1000-1100 with stock covnerter.

You're tire pressure it way too high. ET Streets work best on Lightnings between 16-18 psi. I don't like to run them lower than that, because with the short sidewalls, I've seen the rim bead slam the ground with less air pressure.

Long burnouts just waste rubber. Overheating the tire will cause very inconsistant 60fts. A general rule of thumb is spin them for about 5 seconds after you start seeing smoke coming off them.

Also, if you are running the wider 11.5s, we've found they work WAY better on an 8 inch rim. Many people run the 11.5s on the 10 inch rim, and they don't work as well like that. If you check MTs rim suggestion for that tire, it's maximum 9 inches. That's not a typo.

Hope this helps!!

 

The tires are the 10.5's and I was launching at 1500. I had no wheel spin and it seemed liked it hooked real good. Maybe I should tone down the smoke show a little . I forgot to mention there where 3 other stock L's and they couldn't even get in the 13's. The best I seen was 14.05

 

If the tire aren't spinning, there isn't much more to be gained.

 

Just do what I said and I GUARANTEE that you will drop your 60'...I've asked questions on here and experimented @ the track and you CAN gain more ET even if your not spinning!!!
The problem is that your no letting the stall converter "Flash" enough!!! Launch from 1000rpm and you'll drop at least .1-.15 off your 60'!!!!!! Remember to drop that air pressure to 14-16psi!!!


Chikin@Charter.net
---------------------
Black '01
Born on 5-3-01
#3603 of 6381
424HP/528ft.lbs @ Normal Temp. w/o N2O
LFP 2600 P.I. Stall Converter
JL Logocaps w/Keychain
JL 3# Lower Pulley
Sean Hyland 2# Upper Pulley
JDM Cold Air
JDM Boost Bypass
JDM/Accufab Throttle Body
JDM Longtubes w/ Silver-Bullet cat-back
JDM Cobra R pump
JDM Eletric Fan
JDM 2” Drop Shackles
PSP 4-Way Autologic Chip ( Tow, Street,Track, N20 )
PSP FactoryTech Valvebody
PSP Deep Tranny Pan
PSP DriveShaftLoop
PSP Truck-Traks
PSP Nitrous Plate
Nitrous Express 50-150 Kit ( Can’t decide which jets to use )
NGK / TR6’s ( .040gap )
Hoosier DOT’s 28 x 10 x 16
NEXT:
Built Shortblock w/Ported Heads
Monster Box Tranny
JDM 166 Blower and 100mm MAF
AND DEFINITELY SOME BIGGER SLICKS

 

Thanks for the reply guys! Next time I will try to lower to 16 lbs to start with. I will try to launch from 1000 instead of 1500 also. I thought it was best to launch at a higher rpm if it would hold, Guess I was arong on that one!! I think the weather also played a factor. It was very humid out that night. Almost everyone was bithcing about their times. Hopefully the next time I post I will be a memeber of the 12 sec club!!

 

I found the sweet spot with most slicks was closer to the 10-12 pounds of air range. Not sure how much the Hoosiers vary from the MT's, but low pressure = more sidewall flex = more rubber on the ground.

 

You could also break a seal on the launch due to low air pressure up against the sidewall and wheel. And as Sal stated earlier you could smack the ground with the rim bead on launch. Oh and you could get a little squirley top end.

--Joe

 

Thats why you use tubes and bead screws... and regardless its a trial and error approach, making runs while decreasing/increasing air pressure in 1 pound increments.

Like I said, no Hoosier experience, but I have run the MTs at over 130 mph at 11 #s, with minimal squirrellage.

 

If you have slicks, why wouldn't you want to launch at the highest RPM possible?? Why go at 1000RPM when you can go at 1500RPM without spin?? Did i miss something?


CHIKIN1
The problem is that your no letting the stall converter "Flash" enough!!!

What's this?

 

Its kinda like holding a 5-speed car at 1800rpms and then all of a sudden dumping the clutch and nailing it at the same time...It makes the truck hit the tires harder!!!

 

Ripper, I e-mailed you on those shackles and drop your tire pressure and leave at 1200 on those et strs, that worked wounders for me youll see.jeff

 

Hey RIP,
Several things here... #1, The air temp/pressure difference is always a factor. You can only compare e.t's with different tires on the same day or atleast similar conditions. #2 The overall circumference of the tire is a factor (not the rim size), Stock tire height is aprox. 28", If you went with 26" slicks them you will lower your effective gear ratio and possibly lower you trap MPH.
#3, You need to run atleast one heat cycle on slicks before they will grip properly, if you were racing them right "out of the box" then next time they will be heat-cycled and should be faster, however, as someone already said if they aint spinning your not gonna gain a whole lot more, unless you launch harder!! GOOD LUCK!!!

 

I think i'm still missing the point here.... If you have tires good enough to launch at say, 4,000rpm without spinning, why not launch at 4,000rpm?? Wouldn't that gain you a quicker ET than launching at say, 1200rpm??