i went to the track again with new stall and 8 point roll bar i also changed the govoner weights got the trans to shift at 6700 into second and went through the top end in second at 6600. spun about 10 feet off the line got a best of 13.01 at 105 im thinking about going with the 4.11's with 26" tire would this raise the mph i want to go through the top end at about 6500. if i can get this thing to hook could i get it in the 11's or am i stuck in the 12's

 

13.01@105 even with wheel spin is nowhere near 11 sec time slips. seems you are running the correct et/mph. now if you ran 13.01@ like 115mph then we could say you had traction problems

 

no im saying if i got the new gears a bigger carb and got it to hook up if i would be close to 11's beacuse isnt 105 good for mid 12's

 

105 mph is good for around a 12.50 et but to go from a 12.50 to 11.99 is a big jump. I just looked at your combo you should be able to tune it to bottom 12s for shure change the gear and the carb change will help also.

 

ET reflects how well your car hooks and accelerates. MPH reflects and indicates how much horsepower your motor is making.

Your mph (105) is a little low for the power you'd expect from the engine parts you have. Should be around 108-110mph.
The fact that you're going thru the traps at 6600rpm in second indicates that your converter is slipping a lot in the traps. If you had no converter slippage your rpm thru the traps should be 5480rpm. Your 6600rpm indicates over 20% slippage. A good hi stall should have not more than 10-12% slippage.

Part of the problem is the rear gear ratio. IT's way way too low.
This alone can cause the converter to seem to slip excessivly in the top end and kill the MPH. A high stall converter must be matched with a high rear gear ratio or it is very ineffecient.
Once you get some gear in it you can re-evaluate the converter lock up.
4.10's minimum 4.56:1 best.

Your big dart heads could use a lot more valve lift. The cam duration +/- is fine. (I have this same isky cam and the net measured valve lift with lash is only .482" @ the valve.) {good for me, not the best for you}
What is the actual compression ratio of your motor?
A non-blueprinted 355 build with typical rebuilder flat tops on a undecked block, could be as low as 9.3:1 or even lower if say the heads are not exactly 64cc.
Should be 10.3:1 to 10.5:1 for pump gas and max all out performance.

11's is going to require 80 more horsepower than what you're making now.
You should be well into the 12's @108-110MPH with a gear change, some traction tuning and carb/ ignition tuning. I'd suggest some rear airbags ( Air-lift) to help equalize the right/left wheel traction
(improves the "limited slip" posi traction lockup, pinion angle and lower control arm geometry on launch)
What are your 60ft times and 1/8th mile et and MPH so far?

 

Do a compression test and a leak down test on your motor.
Your cranking compression test (with a fully charged battery) should be 180PSI +/-. A compression test much less than this with a acceptable leak down test indicates that the actual mechanical compression ratio is likely too low for maximum performance on pump gas. (92 octane).

 

60" 1.911
1/8 8.365
1/8 84.16

ya i still have alot of tuning to do theres 68/72 jets in the carb not sure if thats to small. spark plugs are clean it is a stock deck block. im just hopeing i can get low 12's with whats in the motor right now. is the 650dp ok or should i really look into a 750.

 

After you replace the gear then look into a 750 DP. carb. I have used a 650 DP that I worked over for years had it on the 380 ci motor also with dart heads it went 11.30s I replaced it with a carb shop 750 gained 10 hp avg at the track I did not see any better times.

 

I would go up to a 76-77 sec jet. I would lock out the timing (34-36 full time)
get the 4.10's or 4.56's and drag bags and work from there.
Do a compression test. If the block was not decked and you used a H345P piston and .040" gasket, the cr will be too low.

 

i just found out that i had a broken pushrod when i ran the 13.01. I went to the track tonight with all the cylinders and ran a

60ft. 1.771
1/8. 7.721 88mph
1/4 12.10 113mph

still shifting at 6700 out of first and going through the trap at 6600rpm in second.
second and third runs the car was breaking up down the track not sure why yet think its electrical. tires hooked alot better this time. girlfreinds first time running the camera lol

http://www.youtube.com/watch?v=ps6rBqJeeZU

 

Good deal now change the gear high 11s for shure. Did you run uncaped before?

 

yes

 

Wow, big difference. I guess having al the pushrods in the motor helps a lot
Now based on your numbers you converter is within the usually slip range (12%).
Will likey improve with 4.10's. Should put you solidly in the 11's.

 

Also i was woundering if the mph is correct for my time. ya alot more fun having all the cylinders work when i seen that 12.10 i had the biggest smile on my face.

 

Yes it is. Its is average for your chassis prep level.
if you multiply et x mph you get a result in the 1300 range. (1300 to 1400)

A lower result indicates a good et (good launch and acceleration down the track relative to the MPH.
As the launch improves this number will be lower with the same horsepower. A very low result can also indicate a top end power problem where the MPH is lower than you would expect from the et.
If you take all your et slips from that day and multiply the et's with the mph's and find the lowest (best) result. then divide the average mph into the lowest result, you'll get a best potential et for the day.
That should be your dial in.

Your car also has a few tenths in it with jetting timing tuning. But seriously needs the gear.
that isky cam with its modest valve lift is working very well for you. Better than I would have expected.
I've never seen a car yet that didn't run well with an Isky cam in the motor.

 

I would say u seem about right my cars best with the old owner(friend and was there too see) is a 12.90@107MPH so 13.00@105MPH seems good.

My Roc weighs in at 3250 without a driver.

This is on bald MT Ets...mods in sig

Jay

 

what do you think my mph will be with the 4.11's in it. would it go up or stay just about the same.

 

**** if you can do a 12.10 with 2.73's and a 355 on motor your doin damn good. slap in those 4.11's and say hi to 11.70's and some air under the front tires.

 

4.11 with 28 in tires maybe

 

im going to try my hardest to do it on 26's

 

how quick can you go on a 26x10.50 slick tire? i can imagine with proper setup that tire will be enough there are guys in the 8's and 7's i believe with drag radials

 

i've got buddies in the 10s on 26" slicks without too much trouble, but they aren't as consistent as the 28" slicks.

 

what kind of mph am i looking at with the gears and if i throw some .015 headgaskets on it over the stock ones would it make much of a differance.

 

head gasket may give you a few more ponies due to mild change in compression and tighter quench zone

gears should give you 2-3 mph i'd say on that combo since 2.73's are very tall for that combo. i know i picked up around 1-2mph average from 2.77's to 3.27's on my L98, its just responded abit better to more gear