MAFT and Nitrous? Timing question

[Pewter2K1]

I was looking at the MAFT from Ramchargers, and I found a guy selling one cheap, I know it wont be able to adjust timing but the A/F is just as crutial.

Right now I am at a 100 shot, and everything seems well, looking to put the 125 shot in and I have upgraded the fuel pump. I know its reccommended to pull 2 degrees of timing out for the big shots, I have a nitrous cam in the car, and I believe the card says -4 on it. Can I safely run the car with just a A/F tune or is the timing really important?

Oh by the way, I will be tuning it on the dyno so i should be able to keep the car in a controlled environment why I check.

[Nachius]

James sprayed a 120 dry shot on stock timing without a problem.

If its tuned properly and you're getting plenty of fuel w/ minor to no knock I think you'll be fine on the 125 shot without retarding timing!

[1998silverbird]

Originally posted by Pewter2K1:
I was looking at the MAFT from Ramchargers, and I found a guy selling one cheap, I know it wont be able to adjust timing but the A/F is just as crutial.

Right now I am at a 100 shot, and everything seems well, looking to put the 125 shot in and I have upgraded the fuel pump. I know its reccommended to pull 2 degrees of timing out for the big shots, I have a nitrous cam in the car, and I believe the card says -4 on it. Can I safely run the car with just a A/F tune or is the timing really important?

Oh by the way, I will be tuning it on the dyno so i should be able to keep the car in a controlled environment why I check.

Your rear end is going to go if you put the 125 shot.. I was spraying the 90 shot for 6 months or so then I upeed it to 125.. I went through 3 bottles.. The last time I sprayed it I let off at 110 and My rear was whining like a 8itch.. Its been whining ever since.. Greg at Street Motorsports said I stretched the rear end Housing.. I have never launched off spray or hit the nitrous in 1st gear.. The last time I sprayed it in 1st gear was on my 50 shot about 2 years ago.. Your going to be making over 400ftlbs of tq to the wheels.. Thats to much for a 10 bolt.. save for a 12 bolt or 9 inch.. My 10 bolt lasted 2 weeks on the 125 and I never hit the track with it..

[12secondv6]

I'd like to see others reduce timing when going over a 100 shot.

To be safe I would run GT 100 race gas with stock timing.

I haven't had a successful run on a 125 wet shot.... EVER so I don't know

[John_D.]

Monitor your knock retard... I was getting 10 degrees of knock retard on a 150 shot. Much less on a 120 shot though. If I had taken out about 2-4 degrees of timing, I believe all 10 degrees of the kr would have come out.

[Pewter2K1]

Jeff, you stretched the housing???? sounds like some BS to me... that thing is pretty thick metal... I will have to get some auto tap to take to the dyno and see what everything is doing KR wise... Thanks for the help... will see what happens soon!

[1998silverbird]

Well we tore the rear apart and the Gears looked fine, diff looked fine, axles looked fine, the pinion was still shimmed right. we replaced all the bearings and shims.. when doing so we noticed a crack In the housing above the pinion.. It goes from the yoke to the gear on the pinion.. John (trymyz) had the same problem.. I am just letting you know.. With a 125 shot the rear is just waiting to break..

[12secondv6]

The rear is waiting to break on a dead hook 100 wet shot!

I SPIN to a 1.58! With weeney 3:23's!

[Shirl]

mine has held up just fine....>>knock on wood>> [img]graemlins/burnout.gif[/img]