[67chevelle406]

Ok the track opens next week I would like to see the Chevelle go 11.9s. I think I am asking a lot but I want to try my best pass was [email protected] with a 1.74 60ft. On anothe pass I did get a 1.69 60ft but car wasn't running rite. My combo is in my Signature I just want to tune what I have and not change any parts. I have the timing at 36 total,jetting is 75s front and 82s rear I have a 2inch open carb spacer to try and was thinking of going to 84s in the rear. I run 17inch Nitto drag radials at 20psi I am going to play with tire press. And also press. In air bags. I have been leaving just above idle and easing into it to keep from spinning. I think lower press. And more heat in the tires I can leave harder. Also going to play with shift RPM and see what I can get. I think I got most of it covered but anybody has suggestions that may help or something I am missing I would appreciate the help. Thank you

 

[Dave427]

60 ft.
I know the whole race isn't in the 60 ft but it sure does help.
It takes alot more horsepower to pick up ET with a lousy 60 ft.
You want to concentrate on getting your 60 ft in the low 1.6's to high 1.5's to overcome the lack of top end your engine doesn't make because of your smallish cam.
Putting larger jets in the back of your 750 Vacuum will just cause the secondary's to open slower, the engine's air flow is what causes them to open, and making it richer might slow them down.
I would find some other 15" rims and put a bias slick on it and launch it and not worry about it spinnning too easy with your 17's.

Dave

 

[67chevelle406]

60 ft.
I know the whole race isn't in the 60 ft but it sure does help.
It takes alot more horsepower to pick up ET with a lousy 60 ft.
You want to concentrate on getting your 60 ft in the low 1.6's to high 1.5's to overcome the lack of top end your engine doesn't make because of your smallish cam.
Putting larger jets in the back of your 750 Vacuum will just cause the secondary's to open slower, the engine's air flow is what causes them to open, and making it richer might slow them down.
I would find some other 15" rims and put a bias slick on it and launch it and not worry about it spinnning too easy with your 17's.

Dave

Thanks Dave I know the cam is way to small I have posted several times about changing it and still have not. I didn't realize the jet size would efect the carb that way I just assumed I would get mor fuel and run better up top maybe I should try jetting down a little. I also know I should go with some 15s for some extra sidewall and a better tire then some skinnies on the front but for some stupid reason it think the car should be ran the way its drove on the street I know its pretty dumb but I've always been that way. I also think that with ther rite press. And proper launch the car will 60 in the lower 1.6s when it went the 1.69 it pulled the left front a little. Thanks again

 

[crazydavey]

Hey Kevin,

I agree with Dave, your best opportunity is in your 60'. The problem with the Nitto's is aggrivated by the fact they are 17" which gives you no flex in the sidewalls. '67's have a long wheelbase so getting the weight to transfer is very important.

As Dave said borrowing a set of bias slicks would allow you to use the suspension better. I would suggest 10-15 lbs. in the right rear bag, little if any in the left. Make sure you unhook or remove your front swaybar, that will help loosen up the front end. I would play with your launch and try different rpm's. Off idle is going to give you the hardest tire hit, as you go up on the converter it should lessen the hit by pre-loading the suspension, at least that's the reaction I get out of mine.

You said you have played with shift points, can you share that? I don't mean for this to be a stupid comment but remove any weight that you can. If you are running a similar tire in the front (wide 17") that's not helping either. If you can put something that's as narrow as possible on the front and air them up.

Wish I was closer, I have a spare set of wheels and tires that would probably take close to 2 tenths off your car. If you really want that 11 second slip make an all out attempt and I think you can get it!

Go for it Kevin, 67's rock....:thumbsup:

 

[67chevelle406]

Hey Kevin,

I agree with Dave, your best opportunity is in your 60'. The problem with the Nitto's is aggrivated by the fact they are 17" which gives you no flex in the sidewalls. '67's have a long wheelbase so getting the weight to transfer is very important.

As Dave said borrowing a set of bias slicks would allow you to use the suspension better. I would suggest 10-15 lbs. in the right rear bag, little if any in the left. Make sure you unhook or remove your front swaybar, that will help loosen up the front end. I would play with your launch and try different rpm's. Off idle is going to give you the hardest tire hit, as you go up on the converter it should lessen the hit by pre-loading the suspension, at least that's the reaction I get out of mine.

You said you have played with shift points, can you share that? I don't mean for this to be a stupid comment but remove any weight that you can. If you are running a similar tire in the front (wide 17") that's not helping either. If you can put something that's as narrow as possible on the front and air them up.

Wish I was closer, I have a spare set of wheels and tires that would probably take close to 2 tenths off your car. If you really want that 11 second slip make an all out attempt and I think you can get it!

Go for it Kevin, 67's rock....:thumbsup:

Thanks man I have looked at pics of your cars. You and your wife have nice rides that run very well. The only thing I see that you are wrong about is when you say you wish you lived closer to me I would rather live closer to you the wheather is much better by you than what we have in Ohio LOL. I have thaught about finding a set of welds to use at the track. I have tried a few different shift points I started at around 5400 and went up to around 6000 seems best at 5400-5500 I finally have the car running good and staying together so I will use this year to tune it seems pretty close but I think it will do better. Maybe with tuning and the wind going the rite way I can get a 11.9999.

 

[crazydavey]

thanks Kevin....yeah I spent a lot of time at our facility up in Troy when I was still working, it was always good to get back to the sun during the winter....

I think you're right there with shift points, I was going to say around 5600. Good luck on your quest, I think you'll get there...

 

[67chevelle406]

thanks Kevin....yeah I spent a lot of time at our facility up in Troy when I was still working, it was always good to get back to the sun during the winter....

I think you're right there with shift points, I was going to say around 5600. Good luck on your quest, I think you'll get there...

Pretty small world I'm not even an hour from Troy.

 

[66 BRONZE]

60 ft.
I know the whole race isn't in the 60 ft but it sure does help.
It takes alot more horsepower to pick up ET with a lousy 60 ft.
You want to concentrate on getting your 60 ft in the low 1.6's to high 1.5's to overcome the lack of top end your engine doesn't make because of your smallish cam.
Putting larger jets in the back of your 750 Vacuum will just cause the secondary's to open slower, the engine's air flow is what causes them to open, and making it richer might slow them down.
I would find some other 15" rims and put a bias slick on it and launch it and not worry about it spinnning too easy with your 17's.

Dave

Long wheel base car with a low profile drag radial is not the optimum tire/set-up, as said before you need a taller sidewall slick to get your 60ft times down.

 

[67chevelle406]

Well I may end up putting 15s on the Chevelle with M/T drag radials or ET streets. we might be buying a 68 Camaro for my wife and if so we will put the 17s on it. We have been trying for a couple months to get it but had to sell her 51 truck first guy just left from looking at it and supposed to come pick it up tomarrow hop it works out also thaught about putting the 406 in it and biulding a motor for the Chevelle but not planning much til he puts $ in my hand.