Went to the track again to maybe get my last run before winter sets in. There was a faint drizzle and 53 deg. Ran 7 passes, each one quicker as I was trying different strategies. My last being my best with a 4500 rpm launch, 7k shifts and 11 psi.

1.76 60 ft
11.84 @ 115mph

Decent 60ft but none the less I felt a fair amount of wheelspin in 1st and 2nd!

Drier track, higher launch, earlier 1-2 shift, I feel an 11.5x for sure. Seat time being my biggest friend tonight.

 

Good run man. Glad to see your times improving. What rear tires are you running?

 

Thnx, MT et streets 28x12.5

 

Awesome run! Were there no problems with shifting into gear at high RPMs? My Boss is being built next week and this problem that others are having is really bugging me, as my Boss will see the dragstrip too!

 

Great times! But why did you shift below the hp peak of 7400? I think that shifting right at 7400 would be good for a .10 or .15??

 

No shifting problems at all this time. I'm starting to think it was me pulling the shifter more towards me than straight down. I made an effort to go straight down and I never missed.

As far as shift rpm, on my previous runs a few weeks ago, I couldn't get better than a 12.2 shifting at 7400. It was suggested on this forum to try different shift rpms and it worked. Drag racing is more about torque than HP.

 

Congrats. Great time.




Regular GT's tend to have those problems; haven't really seen them with Boss.

 

Incorrect

 

Very nice time. Good to hear that you have no shifting problems. I do agree that seat time is a huge factor.

 

Time over a given distance IS horsepower. I think that with what seemed like a awesome drive mod that if you drove the exact same way but shifted 400 rpm higher you would have run .10 or slow faster. Either way I am glad you are getting the shifting down, I personally never had an issue with the MT82 and agree with you that you have to be concious of your shift style and it makes a world of difference. BTW I am too much of a pu&&y to take mine donw the track

 

I didn't want to bore you guys with all the details of my runs, I hate those wordy posts. My first run was shifting as 7400 and a good chunk of wheelspin. and it netted me a 12.2 @ 117. The next couple of runs were better due to 60ft and same shifting rpm, just higher launch rpm best I got was a 11.979 @ 115. My last two runs were identical launch of 4500 but with earlier shifts (200rpm) incremements until I got my 11.84. My first visit to the track I did a few runs shifting around 7600 and I got 12.4. When I said "seat time" I didn't mean learning how to drag race, I meant learning what the car liked. I am never one shy of spinning an engine to moon if it means lower e.t.s trust me. It was mind boggling to me why I was seeing other "more stock" cars turning quicker e.t.s than me. So I took the advice of a forum member and shifted earlier, it worked for me and I can't argue with that. I will definately keep trying different rpms, most likely higher and higher launches. I am hell bent on a sub 11.5

BTW: after a few runs I realized I hadn't set my rear shocks to 1, fronts are already at 3, I did that and it really helped my 60ft.

 

So were you still in 4th gear going through the traps? So setting the shocks 3 in the front and 1 in the back worked best for you? I would've guessed the reverse would be best. Thanks a lot for sharing your experiences at the dragstrip.

 

Yes it worked best, remember you want the weight to transfer to the rear wheels as soon as possible. Drag suspensions are typically "softer" on the rear for that purpose.

 

That's some great driving, keep practicing!

 

SoFLO5GT, yes I did cross in 4th. I keep forgetting to check at what rpm though.

 

Nice times!

 

True in a sense, False.

A drag car's suspension is stiffer in the rear than in the front. In fact, going to a stiffer (rebound) setting in the rear will help with wheel hop. Squatting is generally bad for a drag car (loss of forward energy). Similar in the front albeit a nice looking wheel stand. A softer front setting will help weight transfer to the point of full droop. The fronts shocks are not dampened correctly to take full advantage of weight transfer regardless (need less rebound).

In general: Stiffer spring in the rear, lighter spring in front, reduce rebound in front, remove front sway bar, add a heavier adj. rear bar, add a little preload to the right rear, adjust pinion angle, etc. There is plenty more by maximizing IC and CG (adj. LCA/UCA).

Shocking the rear tires too fast or too hard will net wheel spin. Too little or too late, the car might initially hook, but unload shortly after.

I recall a few people on this board setting the shocks at 5r and 1f, then adjusting the rear if needed. As several stated, peak horsepower is your friend, not torque, especially with a manual. With a 117 mph trap, your leaving a little on the table. Try 7,000 rpm 1-2 shift, 7400 2-3 and 3-4. The short shifting might help reduce wheel spin.

Dave

 

Interesting and good experienced info. The thing that I noticed is that when I went to a 4500 launch I got wheel hop, that's when I went to the rear 1 setting and it went away. I am seriously trying to to the 1-2 shift at 7000, but at the 4500 launch and slight wheelspin I was getting I was at 7400 quick! the other shifts I was able to manipulate until I saw the drop in e.t.'s. I have no dyno #'s to back this up, but is it possible that being that my car has an aftermarket tune the power peak dropped a few hundred rpm? I know I definately have a lot more under the curve than it did stock. The street tires will fry at any stab of the throttle through the first 4 gears, where on the factory tune it was a very subtle, controllable, acceleration.

 

I like this discussion. The wheel hop stopped with it softer in the rear. I would probably soften up the from some also. Weight transfer should be great this way. One thing you guys have to remember is that the Boss wasn't intended for drags. Geometry set up is intended for road racing. So softer in the rear may be right for dig racing. Drag car will run stiff rear but they also run slicks that don't break free as easily. A little more working on shift points should bring up that mph back up a couple and et. If you can get that good of a launch and trap out at 7400 in 4th with no spin, that's the best it's gonna get. And I'm really surprised that the Boss will do that well on the strip. Just needs a blower.

 

It used to work on my previous Vettes. I always ordered them with the Magnetic Selective Ride control feature and I would switch to soft for drag racing and I would cut 1.5x 60 ft.! I would leave it on sport mode and the tires would spin and hop (slightly) my 60 ft. would change to around 1.6-1.7