I am kinda confused on my reults with the new motor. I have posted the combo before but here goes again dart block 406cid 12.8comp afr 227 heads, with cleanup work custom solid roller "nitrous grind" specs 260-277 dur@50 662-662 lift 112ls and 8deg advance all eagle rotating assembly and srp pistons professional products tall single plane intake ported quickfuel 950 carb nx gemini twin plate hooker 1 3/4 headers 3in collector with 2 1/2 duals with dynomax bullets TH350 3800 custom billet nitrous stall 3.70 gears car weighs 3400lbs with me in it. Car ran 6.70's and 6.80's all motor last 2 times out. On spray it went some 6.30's with a 100 shot 60ft was high 1.30s to low 1.40's traction was kind of an issue later in the day. I figuired this car would have gone at least some 6.50's on motor with this setup and some 5.80's on a 250 shot......... Maybe I just need to dyno it and go from there..... im not sure yet.... any ideas??????

I think you need to do something with your exhaust system, unless the "3in collector with 2 1/2 duals with dynomax bullets" was a misprint. I would think 2 1/2" exhaust would be a big restriction on your combo.
You are right tho, I too feel it shouls be a bit faster in the 1/8 mile, generaly nitrous cars run the first half better than the later half.
Did you pull a plug at the end of the run?
Just trying to figure some things out before going into it too deep.
DonB.

with the power that motor is making, i'd say the exhuast is a little bit of a restriction, but not too much of one...

how did you arrive at 8degrees of advance on the cam? was there any engine dynoing of it to determin where it liked to be?

I thought my S-10 daily driver should have gone a 7.50 instead of 7.80 but all we can come up with is the mild nitrous rollers 112 LS is hurting power compared to a 108.I haven't sprayed mine yet but I think you picking up .5 with only a 100 shot at the ET your running on motor is testament to the advantage of the wider LS with nitrous.Put 250 to it and I bet something good will happen!

I think a 6.7 in the 1/8th is extremely respectable out of a 23* headed motor naturally aspirated.

My friends goes 6.40's all motor in a 3200lb car. Motor is a 406, 12.5comp, afr 220's ported, solid roller, and all the rest is the smae as mine except he has a 5300 stall, and a trans brake....

I got the specs for that cam from motor machine "aka" David Vizards Cam Doctor. If you have not heard of him, just ask around. He is the cam guru.

The cam they speced out was 260-277 dur@50 632-662 lift 112ls and 8deg advance ground in the cam.

The only diff in what i had ground was 4deg in the cam and then 4 more with my rollmaster timing set. and my lift is 662-662. The cam guys said it was easier for them to grind it like that due to some lobe specs, and my 1.6 rockers....

Yeah your motor isn't exactly ideal for all motor passes either . Your converter is too tight for all motor passes. I think it is extremely impressive on the motor for a nitrous setup, hell that would be mid-low 10's in the 1/4 :shrug:.

Yeah the plugs look a tad on the lean side on motor, and almost perfect on the nitorus pass. I am going to switch to a 3in system. I need to see some pics though to see how I can run it neatly. It doesnt get street driven to much anymore so ground clearance isint a big issue.....

Oh and on a 200 shot it spun the tires and went a 6.teen at only 114, and on the 100 shot pass it went a 6.32 at 110... my motor passes averaged that day were 6.83's at 102.74

It just seems to kinda stop pulling around 6500. My friends are telling me it seems like it is screaming and going nowhere.... I wonder if just need to get more fuel to it for the motor passes.... man I need a dyno day !!


Nice dyno numbers by the way......

Ahh got ya on the cam definately have heard of him - we had him spec out a cam for a motor at the shop i work part time at.

a chassis dyno i think would help you immensly, and honestly, i think we are all just taking shots in the dark at this point.

could be an exhuast restriction, hell, far fetched, but could be the carb is starting to fail or needs some different parts than what it came with...

How do you like your quickfuel 950 out of curiosity?

all I can say is that it is GREAT!!! I called them to order the carb over a year ago for my old setup. They set up the carb and sent it to me. I went to the dyno and out of the box the af was 12.9 on the motor..... I could not ask for a better carb.....