28x11.50 16lt et streets on my lx..starting air pres at the track??

[93notch]

trying these tires out on my fi lx tonight at milan. does anyone have a good idea of what a decent starting pressure might be? if it matters to the decision im making 525rwhp. tremec 5 speed..launch bags set at 10 psi...southside lift bars , 4.30 with a detroit. thanks for any help.. i want to launch but stay stable at the top end too!!

[RIXXX93GT]

Depends on track and your suspension. Do you have adjustable shocks? To be safe on your first pass so you have no surprises on the top end I would start at 14-15psi and see how the car reacts on the launch and more importantly from 1000ft to the traps. Dont slam on the brakes from full throttle, just ease off the throttle and let the front suspension load back up before hitting the binders.

[93notch]

started at 16# and 10# in both bags and had no launch. blew off the tires and had a 211 60 ft. ...next pass dropped the tires to 12# and 4# in the bags and dropped the 60 ft to 174. much better. had a little tire shake at mid track but it smoothed out fairly quick and the top end was decent. hurt the clutch leaving off the linelock @5000 though..lol it didnt care for that much after about 3 passes. ill be putting a c4 in it with a brake. hung both fronts out of the hole though...looked cool...lol

[93notch]

by the way...it has 50/50 lakewoods in the rear with southside lift bars and bags in both sides with eibach drag springs and 5 way adj. konis in front set at at 90/10

[93notch]

........and i think the 28" talls hurt me a bit... 26's would have been a better choice im thinkin

[Goober]

How high are you twisting it thru the traps on a good launch?

[dedpedal]

26s might cause you to run out of engine in a 1/4 mile track. I had 4.10s with 26x10s and trapped 11.30s at 120ish. The rpm was 6500 or so. (My shiftlight came on just past the trap on a 6600 pill)

[93notch]

id be guessing because thats one of the things i failed to keep a close eye on but id say between 5 and 5500 and i was shifting around 6300 because i couldnt find my 6800 pill


i never got the launch i wanted. it stuck good but my r's dropped too fast dead out of the hole to get too excited. it recovered quickly... i was killing 9 to 10 sec big blocks out of the hole no problem but you have to twist a sbf to make power and i think it should have been better. im considering some fairly big changes. first a c4 with a brake. then i need an intercooler on that v1. lastly( and the straw that might split the block) a 100 shot at the top end. then the 28" might work. ...im thinkin. the auto i can leave higher off the brake and the squeeze will keep it pulling hard through the trap. ...any input? its either that or ditch the s/c 306 and go 408 with 2 stages. the latter is way more $$$... thats the only thing holding me back. the 306 needs to be re rung but at 13# the best pass i made was a mid 12 @ 112 and that doesnt seem right at all to me.its not making 525..im sure of that. am i chasing a unicorn if i try to hit 10s with that 306?... if so, ill call dart and get my new block coming for the 408 cuz i know i can hit that number with the stroker and juice..

[93notch]

any thoughts?

[Jeff88coupe]

I never used my line lock on the starting line for launching. Line lock is for the burnout box.
You were making alot of changes on each pass to really tell what hurt or helped. I use to run ~15# in the passenger side rear airbag. With a stick and launching on sticky tires...5500-6k would be around where I launched (or higher) depending on how well the track was working.

[93notch]

yah ... i know where to use the line lock.lol .. it really bears very little relevance that i also used it in between the beams other than that instead of snapping the clutch pedal from the floor, i was holding it right at the point of engagement and using the linelock to keep me from creeping at the tree dropped. at launch i just let the button go at the same time as the clutch. the only thing i did wrong there was that i had the driveline loaded too much and burnt the clutch boosting at 5000 rpm on the line. as far as changes go i only made two..bag press and tire press. dropping the 60' from 211 to 174 with that being the only change seems right to me. if youre leaving with daylight under both fronts and the rear isnt rebounding id say the suspension is working ..wouldnt you?