SO i went to the track last night. And i started off at a 14.0 @ 100mph/ 60' was 2.3. then progressively brought it down to a 13.8@103 mph. my 60' was 2.23. I have a hard time leaving the line without bogging. I don't want to blow up the 10 bolt so i don't want to dump the clutch. I roll into it and then she bogs to about 3500rpm then comes to life at about 4500rpm. I know i should run 4.10's with the 6 speed, will that help the bogging problem? Also based on my mods should i be in the right range? I am also wondering what i should run for a gap on the plugs? i am running just over .030 gap i was running almost .060 on AC Platinums prior to the Rapidfires i have in there now. When i changed them the car didn't act too much different. What do you guys think?

 

What do you guys think?

 

The 4.10s will help with the launch and get you thru the gears quicker. That cam probably needs more gear too OR More RPM to work in it`s power band, (i.e slip the clutch) to keep it in the proper rpm band. The gap sounds right for the keith blacks, spark plug gap wont effect much at your level of performance but the wider the better as long as your coil can handle it and keep the plugs lite. You are losing loads of ET in the 60` you should have no problem with practice getting 1.7`s 1.6`s

 

Thanks for the info man! Yea i am going to get some 4.10's sometime. Not exactly sure when but i would like to in the near future. Yea it deff needs more gear, i roll into it(i don't want to burn up my clutch thought) but i roll into it and it am engaged and she bogs coming out of the hole. My friends 9C1 Caprice (14.8-1/4, Stock) RUINS me out of the hole but i walk past him after i get into 2nd. That 4300+lb Caprice runs good for how freakin heavy it is! Very impressed with it. But i kinda worry a little bit about my 10 bolt, i do not want to break it with a hard launch...

 

i think you need a lot more carb... your MPH is down. a combo like that should trap at a minimum 108mph. And that would indicate a 3500+LB raceweight...I would think a 110mph should be no problem..

 

I ran a 700 DP for a short while and didn't like it... I have always been told nothing over a 700 on a sbc, its just too much... idk i'm a bad tuner too so maybe it was all screwed up. haha

 

well i was guessing thay you have a 4160 vacuum secondary single feed holley.... or do you have a double pumper?

 

I have a Vacuum Secondary 600. 4160 i do believe.

 

Ok i have an update... I went to the track tonight and i am getting better at launching. I ran a best of a 13.5 @105mph. 60' was 2.22 again. Getting better... Cant wait for the 4.10's lol

 

Your 3.23 gears are not helping but 4.10 may be too much. Back when I had a 9 bolt with 3.27 gears, I was getting 1.7 60' times footbraking a TH350 with a 3800 stall converter and 26" tall slicks.

You need to get the rpms up into the powerband to get a better launch. Going to a deeper gear will probably hurt your 60' time. If you increase the torque multiplication, you can easily overpower the tires. Since you mentioned nothing about tires, I have to assume you're running street tires. Some sticky tires can do wonders for traction.

As for blowing up the diff, if you haven't done it on the street yet, it should survive for a while on the dragstrip. Don't expect it to last forever. If you want that hard launch to get a low ET, you'll need to upgrade to something eventually that can take the abuse. I pushed a beefed up 10 bolt into the 11's before finally swapping to a 9" because I installed a transbrake and knew the diff would never survive.

Your plug gap is fine. Large plug gaps work well at low rpm speeds in daily drivers. If the gap is too large, you'll start getting a high rpm miss.

Your camshaft has a powerband in the 1800-6000 range. You should be launching around 2200-2500 rpm. I believe your 6 speed has 4 gears and 2 OD gears. If geared properly and you're shifting around the peak HP, you should cross the finish line in 4th gear.

Bogging can be any number of reasons. If you're launching at part throttle, when you go to WOT, the accelerator pump shot has already used up some or all of it's fuel and you could be experiencing a lean bog from a lack of fuel. As the rpms pick up, more fuel is drawn from the boosters and the engine picks up power. Increasing or adjusting the pump shot with the accelerator cam may fix the bog. The squirter may also be too small to provide enough fuel from the accelerator pump.

 

I cross the line around the top of 4th gear. probably 4-5k from what i remember. I was told to use the "black" accelerator pump cam. I have the whole set... what do you recommend? I think my POSI unit is starting to die also, my quick clean off the tires burnout one wheel spins then i'll stop and do it again and then both will spin so it probably needs a rebuild.... right? Thanks for the reply!

 

I typically try to launch around 3-4k b/c the power comes on at about 3k. I roll into it i dont dump the clutch. If i dump it the right rear tire spins now, last time at the track i dumped it on accident and the tires hooked and the car bogged really really bad, lol that run was like a 14.4 haha. but my POSi must need to be rebuilt i'm guessing. It one wheel peels a lot more often at the track now....

 

What tires are you running? you shouldn't be bogging down launching at that rpm on street tires, should you? I heard slicks will destroy a stock rear 10 bolt also...

 

Im keeping the Rpm's around 3-4k while letting the clutch go smoothly otherwise i spin. I slip the clutch instead of dumping it. Yes that's why i haven't dumped the clutch lol i don't want to tow my car over an hour home.... i run Bridgestone Potenza 245's. I don't want to run slicks and ruin the 10 bolt.

 

Vid of a 0-125ish run i did for fun today. ( on a shut down road of course)

http://www.youtube.com/watch?v=jYZSEHCikBo

After watching stock/mildly modified LS1 vids, my car is deff slower 0-100... 0-60 is close. Kinda annoying lol

 

Also i have noticed about 2-3 in. of vacuum at WOT. I always heard the carb is too small if you have any vacuum at WOT... any fact in that? Thanks