Long story short, bought a 91-92 145mph gauge cluster and tach doesn't work, bought a autogage + shift light tach. Problem solved.

Today I ran:

Reaction: .612
60 FT: 2.570
MPH: 109.55
ET: 13.822

That damn 60 ft is killing me, either way, im fricken impressed, all I have are headers, computer tune and 1.6 rr's. .

With the stock tach I trapped 107.xx. Setting the shift point at 5500 on the real tach got me 2 more mph . Just need traction.

 

109mph!!!! Holy crap! With awesome traction thats near a mid 12! Are you sure that LT1 is a stock motor?

I know that headers are a big gain but you are making me rethink my decision to go with a converted LT1 intake and just just buy a LT1/T56 combo!

 

No and the radar wasn't off, the run before it I hit 108 mph. I was shifting at 5200 at first and was still trapping 106-107. Moved the shift point up to 5500 and started to trap at 108-109. Im gonna show the slips to TexasLT1 when I head up there this friday before someone calls . I may even take pictures of the slips.

 

Not trying to take anything away from you, but the tire spin may actually be helping your mph. For a lot of cars, tirespin puts the car in its powerband better than dead hooking, so when you do get moving you mph better. I mph about 2 mph better on street tires than on slicks, and that is going from a 2.0 60' to a 1.79 60' on sticky tires. May or may not be the same case for you, but I noticed your 60' times are worse than the last time you posted with a slower mph :shrug:.

 

what rpm do you think you were shifting at before?....higher or lower?

 

stock tachs read higher then what the engine is really turning... so he was probly short shifting a lil bit....

 

While you could be right,you have to remember that slicks have a growth factor that effectively changes the gear ratio. while normal radials whith the hard sidewall do not grow.He is most likely going faster because he is actulally shifting at 5500rpm's now

 

Buy some Hoosier QTP's and dump the clutch off the line. Hello mid 12s!

 

Yup, try by 800 rpm's. . My tach was way the hell off. Im not offended by saying the spinning might help, that may be the case,, but at least she hit 109.55 .

 

Probably 4700-4800. My old tach would Peg at the 7000 when I floored it, I had to play it by ear.

 

Take a look in my sig, I was solid 106s on slicks, 107s on street tires! The worse the 60', the better the mph!

 

275hp to the wheels and 3300lbs could very well get you 108mph. i think on a good drag radial or an et street you could see a 12.5@111. if your car was an auto with a 3200 stall you could possibly see low low 12's at 109. i think your probly making around 290whp and you probly will run a 12.5@110 on a 1.80 60'. gotta get it to hook and learn when to modulate the throttle. i think your car is pretty impressive. now get some et with that trap!!!!!

 

i thought LT1s had higher redlines?:shrug: like 6000 atleast

 

Thats LS1's. LT1's stock red line I believe is 5500. I just didn't want to nail the motor. It fricken screams at that high. I could probably be shifting at 5700 with the 1.6 RR's I just don't wanna break the timing chain until I put the cam in. I got a double roller goin on .

 

Ok here it is, they mixed the names up on the slip, I ran a Pontiac grand am. For some reason on that run they didn't print my 60'. I went up to the tower and asked them what it was and got the number. They couldn't fix it though. If there is still any doubt I can try to take a picture of my other slip where I ran 108.xxmph.

 

<best Simpson's voice> Ha ha</simpson's>

Not bad though.

 

Great times. There is a guy here in our club with basically the same set-up as you expect he doesn't have the 1.6's. He has a stock 89 IROC with an LT1/T56 and has SLP headers. He runs 12.9's. Not sure what his MPH is though. Sounds like you will be running similar times in a near future.

 

Stock redline on a LT1 was 5750. If it was completely stock, shift it there. Since you are running 1.6 rockers, shift a little higher.

 

Thats where I shift my '95. Right below the limiter.

 

Ahhh cool, now I know, I also know too late since next week im going to be shifting at 6500 with the CC306. This thing makes power all the way to 6800 but im not that daring.

 

eh i was close 5750. with u shifting there u might trap even higher! wow....i want an LT1....:rockon:

 

The stock redline is 5800, it will read 5750 on datalogs since that is the last point that can be logged before you hit the limiter.

My ’97 WS6 has run 106.99mph STOCK, even through the stock exhaust. Well, I did use an HPP+ to raise the redline to 6400 and my data logs were showing 6375 on every shift, and I have driven a second, identical ’97 WS6 that did not want to rev as easily as mine. Considering that it’s easily 4-500# heavier then any of my 3rd gens and considering that I’m sure that you didn’t bolt it up to stock exhaust, intake… I see absolutely no reason that you couldn’t be trapping just short of 110mph.

I don’t think that the CC306 is a particularly good design for that engine, but you will run faster with it…

 

Yep, I was wrong. Just looked up the stock rev limiter for a stock LT1. It was 5800 on the tach but actual was:

1st gear was 5886
2-6 gear was 5805

I pulled several stock programs to make sure. Nice when you have LT1 Edit to look at stuff

Also Mark, if I remember right, you had great mph and short times but your car didn't ET that well? Mine completely stock, the one time I had it to the track like that, ran 13.50@104 on a 2.0. Changing to 4.10 gears ran 13.18@104.9 on a 1.87. All on GSC's. I did have a K&N, HPP+(for speedo), thermostat, and air foil. But everything else was completely stock.

 

Yep, you need traction *bad*. That's a great MPH you are posting, but 13.80s?? I'm not trying to rag on ya, just want to see you get a better ET. :-) You definately have 12-second potential.

I'm a bracket racer, so ET is everything to me -- MPH is completely secondary. ET wins races.

You need better tires, but I assume you know that. You should still be able to manage something in the 2.0-2.1 range. Even with street tires, I can't see why you shouldn't be in the low 13s. You should try doing whatever it takes to get rolling with as little wheelspin as possible. Wheelspin is your enemy. Ease into the throttle instead of just mashing it. Try a different launch RPM. Try short-shifting into 2nd gear. Have you ever experimented with tire pressure? When I used to race on street tires, I'd typically lower them to 21-23 lbs. You have a lot of free ET waiting to be unleashed. It's all in how you drive it.

As for MPHing better on street tires than slicks, I don't think there is a significant growth factor for slicks on a car running 110 MPH. Top Fuelers, yes. Our cars, no. I would argue that street tires offer much less rolling resistance than slicks, if for no other reason than slicks are rarely ever run with more than 15-18 lbs of pressure, where as street tires are always higher. Also, when I say slicks, I mean ET Drag or ET Streets, not drag radials. Once you try slicks and get into the 12s, you'll never want to race on street tires again!

-Dave

 

Thanks for the tips. Im not trying to compete there. I have brand new tires in the back and im heading up to Houston tomorrow which is a good 3-4 hour drive. So you have to understand I don't want to nail the car too bad considering im doing a cam swap tomorrow. Im actually just practicing a bit. Im not a track guy and its only my third time hitting the track. Im sure if I did a burn out and lowered the back tire pressure I could at least get a 2.1-2.2 60'. I'd love to ET lower but it just doesn't warrant the risk for me.

 

Yea don't let all the LS1 hype get to you, they are great motors but they aren't gods. The LT1's are nothing to shrug off, their great motors besides the people who don't know jack about the optispark system.

 

I'm still learning my abbreviations here.... what is a 1.6 rr?

 

1.6 roller rockers. Adds about .30 lift to the cam.