2.1's for 60' launching as hard as possible, what gives?

My usual launch technique has been to rev the car up to right before the rear brakes start letting loose, then release the brake, let the nose settle, and stomp on it. That was stock.

Since then I have added BMR LCA's and relocation brackets, SFC's, 17" wheels with 275's(Goodyear F1 GS), LT headers, and cutout.

Last time at the track I could barely spin my tires, which would be a good thing except that launching as hard as possible my 60 foots still sucked(in the 2.1 range every time). I would basically rev it till the back tires started letting loose, back off a tiny bit, and then stomp on it(to the floor) as soon as the light went. What the hell is wrong? My times suck considering I ran a 14.0 stock and with all this money in the car my best time was a 13.85!

What could be wrong? I can't launch it any harder but am having no traction problems!

Your wheels are probably taller and heavier than they were before. You have 2.73 gears. Basically you have added weight and increased the diameter of your wheels. Normally, you would go with a smaller rim and taller tire and put some 3.73 gears in it.

That makes sense for my ET's, but shouldn't my 60's be better? My best was a 2.157! I could see sidewall being an issue if I was having traction problems, but I wasn't.

Last year I went from 26" tall tires to 28" tall tires. Traction was not an issue. I wanted to slow my car down in terms of ET to stay above the 12.00 dial in cutoff for Street ET class. My sixty foot times went from 1.56-1.58 to 1.65-1.67. This had the desired result as I was running 11.8's in good weather and now I run 12.0's in good weather. My average mph also went up from 107-108 to 108-110.

JP,

I think we just needed a better night for racing. The conditions were very poor. I had the same problems hooking up, my 60ft times were embarassing. Actually the 2 whole timeslips that I took home were embarassing. I do think that your times are very high and that you just needed better conditions. A good time to go racing is a Sunday at Numedia Raceway. Very easy to hook up on Sundays because of the track prep.

With your mods you should have been in the low 13's and with mine I should have been in the mid to high 13's. 14's just don't cut it for our mods. Better luck next time I guess.

I think your "problem" stems from adding meatier tires, better suspension, and LTs which probably don't do your low-end torque any favors. Ditch the 2.73s in favor of some 3.42s or 3.73s. I guarantee you'll have some traction issues then.

You have 2.73's, so do I.

No matter how I launched, I couldn't get better than 2.0 for a 60 foot :mad:

Gears are just too damn tall!

Spend the money on a 1000 rpm more stall converter and it will work even harder with those hiway gears. Also... if you were using the cutout, you were probably dumping some torque numbers onto the track. WHAT gets a car MOVING hard in those first 60 feet? TORQUE.

Don't forget weather conditions, you cannot compare apples to watermelons! ;) Data... be a DATA noter so you can see why things may do what they do, other than changes you make and be sure to note them too!

HInk :eek:

Thanks guys, I guess I will try another track but I can't see the prep being a problem because like I said, there was no issue getting traction! Weather conditions could have made a difference, even though my last run was in pretty cool weather(and the only time I broke 13.9...). I guess I will have to consider gears, but really hate to lose the highway mileage so I will be exploring other options. And I will try a couple of runs with the cutout closed(or maybe open it halfway down the track) to see what kind of a difference it makes.

Eddie, good to hear from you- where is Numedia raceway? Want to meet up there this sunday or next?

-P.J

Next time out, try crappy tires, or overinflate them.

You want to spin just a little, so you don't bog.

Taking exact note of the BP, DA, Temp, and Humidity is mandatory for comparing results in performance. Heck, I have been at tracks where my times have varied a tenth between rounds due to chnging weather conditions. An 11.8 in April can easily be a 12.2 in July, and the differentce doesn't have to be the temperature, it can be other factors.. Do not underestimate weather, oil temp, tranny temp, and any other factors that can impact your car's performance. Just being 200rpm off on a shift point can cause a significant change in performance, or launching at a slightly different rpm. You need to eliminate the variables in order to quantify performance gain or loss.

P.J,

I don't think I can get to Numedia this weekend but if you would like to go I can give you accurate directions in order to get there. Sunday is most defenatly the best time to go there because all of the pro street guys are there and the track prep is much better. If you go tell them you want to run Trophy and or something else thats like it. Numedia is a great track in my opinion, there are people out there that will disagree. But compared to Maple Grove last Friday it's great.