I managed to sneak out to Capitol Raceway in Crofton, MD last night.

1.79
11.78 @ 123.54

I ended up turning a little more RPM on the big end that I thought I was going to and wound up bouncing off the rev-limiter the last 150 feet of the track.

I was pretty happy with the MPH. The ET still leaves a lot to be desired, but it's coming along. A couple more track trips and I should be able to get the short times back where they need to be.

Street tires all the way around, my normal 275's up front and 315 nittos out back.

Impressive numbers!

congrats!

Very nice numbers. Is that on a 150 shot?

No bottle, it's all motor. It should go pretty close to 140 MPH on the 250 shot.

fuck me running that thing is haulin ass.

I know alignment is critical on our cars. I think a positive 1 degree camber and zero toe will help your 60' time.

Ya, the alignment can be a big deal on our cars. I don't know about everyone's car, but on my car with it set up at .5 negative camber for normal driving, I can achieve my .5 positive camber by tightening the monoleaf bolts about 5/8 of an inch. It's an easy adjustment to make at the track, and you don't sacrifice the tire wear and handling of the more stockish alignment setting. I used a paint pen to make 2 marks on the spring bolts so I know where to set the nuts for .5 pos or .5 neg.

I'm not having a problem with traction (the damn thing will dead hook, lurch, and bog with anything less than a 3500 clutch drop... On 315 nittos wtih 35 PSI in them) my problem is fear of breaking the rear end. As I make passes, and get more comfortable with the car I expect to find the limit of the nittos at about 1.65 or so.

Great times!! How in the world is that hooking on street tires? I cannot get mine to hook at all, unless on drag radials or slicks. Have you done anything to keep that beast on the ground?

If the N2O system is progressive, your rear should hold, but you are pushing it...

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It is on drag radials, the nittos. Granted, those are probably the least sticky drag radial out there.

Anyone whose followed this forum or the other forum for awhile has seen the trouble I've had with the rear end in my car. I broke quite literally everything there was to break (with less than 300 RWHP). In going through that painful (and expensive) process I was forced to learn about the rear ends that our cars have.

The alignment is one trick I posted about years ago on the other forum, along with extending the snubbers, and pre-loading the passenger side of the rear sway bar with a turn buckle instead of the clevis that GM put on there. There's a dozen or more little tricks like that to get these cars to hook, but to be honest I only use a couple.

There's no front sway bar on the car, so that helps.

The car won't dead hook it from a standing start on the street, only on a smooth and moderately prepped track. On the street the nittos do pretty well for me, they'll hook the car at any speed; first gear at any RPM, a 1-2 power shift, etc... On the street I usually bring it up to 2500 or so and use a slower clutch release. Once the clutch is all the way out, I can basically wood the car without going into wheel spin.

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It's not really the power that I'm afraid of, it's the way it's applied to the rear. I broke everything under the sun with almost stock power, so the idea of pure power breaking the rear (while certainly possible) isn't as likely as popping something because the rear end got hit with power before it had a chance to settle down.

From your trap speed, I think our cars have very similar power output, but I still don't think mine hooks as well as yours. This could also be that you are a better driver. Any other tips for setting up the rear? Can you link the write-up that you did? I'd love to read it. How does those tires do on the street?

I don't shock the drivetrain when driving for fear of breaking things. WOW, breaking everything on a near stock motor? Did you shock the drivetrain in the past?

I never did a write up or anything. A good portion of what I know is just regurgitated Jeb Burnette stuff, so nothing ground breaking. The biggest thing I've learned is that you have to apply the power to the rear over time instead of all at once. It can be a very short amount of time, but you must give the rear end time to settle in before smacking it.

A good friend of mine goes pretty consistent 1.5's (with a best of 1.51) in his nitrous powered 96. It's an M6 car, on slicks,comes out on a 150 HP shot, and doesn't have a problem getting about 3 inches of daylight under the front tires. Other than the 4.09 gears, the rear end is completely stock and he's never broken anything.

If you can get the car squatted down and get the half shafts leveled out, the D44 set up is probably as strong as an equivalent solid axle. Hitting the rear with power with some kind of angle in the half shaft / u-joints is what breaks stuff in my opinion. The dual mass lets the car start to move and gets the rear diff moving down before full power hits the rear end.

I ran a McLeod twin disk clutch for awhile when I was making about 275 RWHP. I could break outer stub axles (or spindles as they are usually called on the web) from a roll if I wanted to. The clutch engagement was so instantaneous that the parts just broke. It's like a speed break in a martial arts demonstration. Suspend a board with a rope, allowing the board to hang freely. You could probably hit the board with a sledge hammer and not break the board, it'll just swing away from the hammer when you hit. Have a skilled striker punch or kick the board, and he'll be able to break it without the slightest hint of the rope swinging. Does he hit harder than the sledge hammer? Of course not, he's just much faster. That's my theory behind keeping the rear alive. Hit it with a sledge hammer instead of the ninja kick.

So, my McLeod clutch was like the speed break. My weak motor (275 RWHP) smacking the rear end instantly was more than enough to break everything back there. My buddy with the nitrous 96 (which makes 500 RWHP) and a dual mass flywheel is like the sledge hammer. I'm sure he could break stuff if he wanted to, but his launch technique combined with the dual mass has kept everything together so far.

We've veered off course a little, but if you want we can discuss making a C4 hook up. Why don't we make another thread, titled appropriately, and then the whole board can share what they know. It'll be easier for new people to find it using the search engine too.

Here's a thread I made:

http://www.corvette-guru.com/modules/ ... hp?topic_id=12871&forum=1

Great trap !

In my mind, 123+ mph in a C4 is a good indication of a solid 500 flywheel HP.

Comes to mind to compare that to a C6 Z06..... anybody know what they trap in stock configuration ?

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11.8

I think they show the average stock Z06 on the other forum with a 11.5 @ 124 mph on stock tires..... but something like 10.9 @ 127 mph with aftermarket tires.

I've seen a handful of 06+ Zo6 stockers run at the tracks around here and in NC. 128 MPH isn't out of the question for a well driven car on a nice day.

Ranger went into the 10's on the stock rubber with a stock car, and some other dude went 10.8's with a stock car on stock rubber.

Those cars are making about 450 RWHP stock, in a lighter package than a C4.