35th LE SS

iTrader: (1)

My first time to the track after I installed Yank SS3800, ET Streets, headers and cut-outs. The best 60' was a 1.82? That seems pretty bad. I did pick up 5mph in the 1/8. Previous best stock was 81.5mph to 86.7mph. The track was a little greasy and the weather was hot, density altitude of 2500ft, but car didn't seem to spin. I left the first two runs at 2000, and last to at a little above idle. Seemed to make very little difference. Details below.

1st run

60' 1.8266 (no burnout/best '60) Left at 2000rpm
ET 8.272 86.78mph

2nd run
60' 1.837 (good burnout/left at 2000rpm)
ET 8.293 86.64mph

3rd run
60' 1.8404 (only 1 tire spun on burnout/left at 1000rpm)
ET 8.309 86.89mph

4th run
60' 1.864 (good burnout/left at 1000rpm)
ET 8.298 86.85mph

It just seems like the car should 60' better than a 1.82. I have no suspension mods, but with the ET Streets, I think I could cut a 1.82 with a stock stall. I did autotap one of the runs and the car was running very rich, but still I think the 60' should be better. Going back to the track on Sunday, so any help or suggestions would be helpful. Thanks guys!

gator's 99TA

iTrader: (2)

practice and a decent prepped track and you will be in 1.6 land easily. try going off idle and upping it till the track cant hold it anymore. most auto cars dont need much suspension to get to atleast 1.7x with that stall. oh and stock stall, you would be LUCKY to get high 1.9x on et streets. i bet you were spinning a lot more than you think, esp if you had dual cutouts open!

AL SS590 M6

iTrader: (1)

It is my experience that Yank converters like to be stalled up. The higher that I stall mine the lower the 60' numbers. I'm stalling to 2900 and pulling consistant 1.66-1.69 60's with a totally stock motor at 3585 lb. race weight with the DA in the 1000' range.

unit213

Ya, stall that mother up and drop the hammer.

35th LE SS

iTrader: (1)

Thanks for the replies. I tried to stall it up higher than 2500, but it seemed to start slipping the tires. Maybe the track was just too greasy to even hold that rpm. Like I said above, my best 60' was with no burnout. Maybe by heating the tires up I just made trying to hook up worse. I used 20psi on the ET Streets on the first two runs, and then dropped it to 18psi for the rest of the runs.

I'm heading out to another 1/8 mile track on Sunday, so I'll try your suggestions. Stalling to 2900 woud be great. I'll see what I can do.

Thanks!

MysticZ28

Well there are 3 things here that I see ...

First, tire pressure. You should be down around 14 to 15 lbs, at least. Maybe 13.

Second, first time on new tires, I have to smoke the living **** out of them, probably a good 10-12 second burn out the first half dozen times or so. After that 5 to 6 seconds will suffice.

Last, suspension mods ... they do make a difference. First and formost in consistancy, a well set up suspension and your 60's should all be in .05 range. Once you have it tuned in, your suspension should give you about .5 on average.

Good Luck

Spellbound

Yank ST3500, ET Streets, bonestock rear suspension,3.73's, Bolt ons, launching off idle, 1.58 60'

alexWS6

Drop the tire pressure some, I usually start at 15 PSI.


If that doesnt work just get some 4.10s :p

35th LE SS

iTrader: (1)

Thanks for the suggestions. I skipped going to the track on Sunday, but this Saturday I'm heading down to Virginia Motorsports Park (1/4 Mile IHRA track) to run their test and tune. Should be able to get a lot more runs that the 4 I got the other night. The only bad thing is weather maybe in the high 80's, but track is usually much better than the local track.

I'm waiting for a custom tune for my Predator, so I hope this will help solve some of the tunning issues as well. My O2 readings on EFI Live were between .980-1.100. Obviously super rich. Had previously done some adjustments with MAFT and Predator, and got some .920-.940 readings, but that was without opening the cutouts and weather was less than optimal. Hopefully, I'll get the tune, make some runs on Saturday, and get it on a dyno next week with wideband o2 to get it dialed in.

Ragtop 99

iTrader: (7)

Pressure depends on the size ET Street being used, mods, weight, and prep. I use 26x11.5x16 and normally do just fine launching my boat at 16 - 17lbs. Only at a crappy track have I ever dropped them to 14lbs.

You may not be able to brake stall above 2500 because you'll overpower the brakes. However, if you had problems with spinning on launch when you stall up to 2500, then traction (track prep) was probably your culprit.

98TAauto

iTrader: (2)

why do ya'll need to run below 16psi in your et streets?? Mine hooked awesome at 21PSI!! The lower you run them the more you loose on top end. I cant stand that swayin crap up top from having the tires below 18psi.

i guess im just so use to leaving on nittos and plain street tires that I can make 21psi in et streets hook like a bat outta hell

but ive cut a 1.74 on 275/45/17 dunlop 8000's at 25psi
1.58 60 on 16inch nitto drag radials at 19psi
and a 1.55 on et streets at 21psi

but its no point in dropping below 20psi if you can hook there. Start at 22 and drop untill you hook

also running below 15psi usually needs screws in the rim/tire

if you cant hook at VMP then try MIR. You shoulda came to our shootout may 3rd 1.74 60 cam only on street tires That track bits awesome!!!!

35th LE SS

iTrader: (1)

I went out today on street tires and stalled the car to around 2800. I would think I should be able to get up to 2800-3000 on ET Streets with a properly prepared track. If I can do it on asphalt and street tires, the track should be able to hold more. At the track last weak, the tires started to break lose around 2500 or so. So maybe a 1.82 on a poor track in hot weather wasn't as bad as I thought. Again, thanks for all the suggestions. I'll try them on Saturday.

Pro Stock John

iTrader: (34)

This is one of my favorite subjects.

I'd:
-put the ET's at 17 psi cold to start.
-do a 7-8 second burnout for your first burnout ONLY. If you have stock tires in front, then drive around the water, and back into the water. Spin the tires once and then pull the front of the water box. Do your burnout and when you get out of it, just get off the gas as you roll out.
-Yank stuff likes to be footstalled high.
-If you are running super rich it can make your throttle response soggy. You might want to lean it out to at least 900-925. Running rich as you know with your other cars will load up plugs and hurt performance.
-Shoot for a low 1.6 for now.

98TAauto

iTrader: (2)

id just stall to 2000 and go from there... mine will start to pull ahead around 2400-2500

just cause the verter is a 3800 stall doesnt mean you can stall it up to 3800

wallstAL

Exactly, I power brake up to ariund 2800 and stomp on it! I have yielded times of 1.6's constantly.

gator's 99TA

iTrader: (2)

98TA if you are hooking 1.7x on reg street radials, then you have an AWESOME track! no doubt and not normal compared to the rest of us in teh country!

second, only manuals need to lower the tire pressure that much. i noticed i slowed down BIG TIME when i was at 15 psi but i also am a cam only car and run a big 28x9 slicks! it is best at 17 cold, about 19 psi warm! i have pulled 1.61 and didnt footstall it. i cant wait till i get time to hit the track and stall it up!

98TAauto

iTrader: (2)

oh i agree 100%.. only prob is others that go there have traction issues Guess i just know that track well.

Most M6's i see run 16psi in there et streets and alot of A4's run 18-22 in there. I believe its a few that run 24psi in them and cut 1.5's on here also

just a simple rule of thumb is to start high PSI and drop untill she hooks. You shouldnt have to drop below 16 though

Lane

iTrader: (1)

I agree with 98ta - I NEVER go below 18psi on my Hoosier slicks, and a friend has QTP's, and runs them the same way. Any less and I get wash down the track. The more pressure the better, unless spinning.

98TAauto

iTrader: (2)

thank ya... I just figured if nittos hooked at 18-20psi and Et streets being 3 times as sticky and having no sidewall that they shoulda damn well hook better at 20-22PSI. When i hooked to a 1.56 on my first pass at 21psi i know it was no point in lowering the PSI. I had some of my stang friends tell me I shoulda still lowered them to 12 or some crap. Im like, WTF for cause I hooked at 21?? Bunch of idiots

gator's 99TA

iTrader: (2)

mn6 cars wont hook for the most part above even 17 psi at all, esp if you are lowered like many. i used to go to the track with a lowered 6 speed and 4.10 gears. no way would it hook above even 15 psi. they hit the tires way too hard, esp launching at over 5000 rpms.

different strokes for different folks.