thunderstruck507

iTrader: (18)

Made quite a few passes and played around with shift points some. This was the best pass of the day but it was right after I increased the shifts to 7100 on the 2-3 and even with the rev limit set at 7500 is barely kissed it.

The car was pretty consistently running 95-96mph 1/8 and 117-118mph 1/4.

DA was 1100ft or so.




Previous best was 7.25@95mph and 11.33@118mph. I think that pass would have beat it by a few hundredths if it hadn't hit the rev limiter.

This car just really doesn't want to run out the back very hard, never has.

The transmission is brand new, full rebuild and we set up the 3/4 clutches to .009" clearance wet so they are tight. Only had 350 miles on it at the time of the passes. Hoping there might be some extra parasitic loss there which fades as it breaks in.

I really wish I could get it to run harder out the back. I'm going to try boxing in the air filter and feeding it air from outside the car.

I'm also going to try cutting the cowl block off from the non-function SS hood. I had it done on my old hood and I know for sure it draws air. My thoughts are that downward draw of air might help direct air to exit the engine bay under the car better so it's not as much like pushing a brick through the wind. Might have zero effect but it's free. When I switched hoods and the car had the old cam it never ran as fast after the hood swap (could be coincidence).

I'm running out of things to try. Definitely feel like the car should be a tad faster though.

jhshnh

Get that 60' down. How hard is it spinning?

thunderstruck507

iTrader: (18)

It's not really spinning. Best the car has ever done was a 1.62 and that pass yesterday it might have barely squeaked them.

All my 60fts yesterday were 1.64-1.68 (the slower ones either spun just a hair or got minor hop). The track was completely green from winter and there were a lot of street cars tearing up rubber faster than drag tire cars could put it down.

SS3600 converter, 275/50r15 Hoosier Drag Radial, 3.42 gears

z28241

iTrader: (13)

Nice job Thunder! Whats the car weigh? Have you ever considered going to a steeper gear?

thunderstruck507

iTrader: (18)

Car weighs approximately 3500 completely empty according to CAT truck scales. I weigh around 165-170lbs for a race weight of 3660-3670lbs.

I wouldn't want to go steeper than 3.73 so it doesn't seem worth the bother really.

It's been quite some time since I've been able to check the accuracy of my wideband against another one so there's small chance the afr ratios aren't ideal, but the tune is spot on set to mid 12s around peak torque and tapering to 12.8 in the upper RPMs

SoFla01SSLookinstok

Your car is sweet man! Seems to be running pretty strong. So with the 3.42 gear, & tire size, what rpm are you going through the traps?

6D9

iTrader: (1)

Seems to be running great to me. Only thing I see with these old cars is the poor AERO. Just takes alot more power once in the triple digits to make them move. Also I agree the car would like some more gear. Would help the 60 and trap speed.

thunderstruck507

iTrader: (18)

It's crossing the traps at a little over 6000 if I remember correctly, I'd need to look at a log to know for sure.

Yeah the car def seems to run a lot harder in the 1/8th.

FWIW I was planning on doing gears a while back, at the time I was using a 325/50r15 MT tire which is around 28" I think, went to the current size which measure about 25" tall and it didn't help the 60ft or trap. After that I decided to focus money/effort elsewhere first and come back to gears as a last resort.

I'm not necessarily unhappy with how the car runs at all, just trying to do what I can fairly easy to optimize it. It's still a street car more than anything and gets used for a lot of autox. Hoping to try some road course stuff at Hallet this year. Also planning to drive it to Colorado for vacation. It's def not a 1 trick pony built for the strip.

z28241

iTrader: (13)

Well those ET's arent nothing to shy away from, like i said nice job! I always liked certain restomods and def like yours, I had a couple Chevelles (WAY) back in the day, would love to have one of them back and Do a swap..Keep this thread active Thunder

thunderstruck507

iTrader: (18)

Thanks, for reference do you happen to have one of your slips? Seems your car runs what I was hoping to see mine do, curious how your 1/8th compares. Your 60ft is enough better to get the ET it looks like, but your 1/4 mph is also a little higher.

z28241

iTrader: (13)

trying to upload

z28241

iTrader: (13)

Here see if this works

z28241

iTrader: (13)

I have a plethora of slips i was just looking thru, also for the record im on a 4.10 gear, 4k stall, not quite apples to apples and lil more aerodynamic, ive gone 121mph but the rest of that slip is my best..DA 1151

zzracer

iTrader: (33)

[QUOTE=thunderstruck507;19526090]Car weighs approximately 3500 completely empty according to CAT truck scales. I weigh around 165-170lbs for a race weight of 3660-3670lbs.

I wouldn't want to go steeper than 3.73 so it doesn't seem worth the bother really.

It's been quite some time since I've been able to check the accuracy of my wideband against another one so there's small chance the afr ratios aren't ideal, but the tune is spot on set to mid 12s around peak torque and tapering to 12.8 in the upper RPMs[/QUOT

Every thought about trying a different converter? I have ran the ss3600 ,pt4000 and ss4000. The ss4000 drove around just as nice as the ss3600. The pt4000 I am running now is a little looser driving around but is still fine. I think it would really bring your car alive since we have similar builds and our race weight is close too. You have a little over 100lbs on me.

thunderstruck507

iTrader: (18)

At some point I might get it restalled to a SS4000. I think that would be a higher priority than a gear swap.

I almost did when I had it rebuilt but at the time I was considering nitrous and was concerned about blowing through a 4000.

zzracer

iTrader: (33)

If you are considering spraying it keep the converter you have . It would blow through the converter. A ss4000 would drive almost as good as what you have but hit the tires harder and it would 60 better .

jhshnh

I'm pulling 1.58 60' with a stock engine, but I also have a 4k stall and 4.10 gears... and I spent time dialing in the suspension. But really it depends on if you want a suspension, gears, and stall that radical on the street... to some it's not radical enough! Lol. I'll admit I wouldn't drive mine daily, it just depends on your goals.

Looking at your 1/4 mph your car is very efficient. So from an outsider's view it looks like you've got it dialed in pretty good.

thunderstruck507

iTrader: (18)

Thanks guys,

I'm always chasing the dragon I guess. I'll update again once I've down the mods to the air intake box and hood and get back to the track. Might not be able to do better or even match this once the weather gets hot...DA at this track goes up to 3000ft pretty easily.

About the lowest I've ever ran in was around 700ft. Sometimes there can be a tail wind and sometimes a head wind. It's out in the middle of a large field area near Kansas so you never really know haha.

thunderstruck507

iTrader: (18)

Was going to try to go back to the track yesterday but during a spirited drive Saturday I began having severe fueling issues and barely got the car home from the scenic route.

By the time I did the fuel pump was whining severely. Luckily a neighbor had a Walbro for his LS swap truck project so I was able to switch them out. Problem seems to have gone away but it wasn't nearly as hot outside Sun as Sat so I'm going to hold off until I can put it through some more abuse to confirm before driving 2 hours from home to the track.

Pump is a Walbro 255 external mounted above the rear axle. Managed to get something like 8-9 years out of it so I can't complain.

SSANIMAL

iTrader: (10)

Like mentioned above that SS3600 is too tight for your setup. What are your shift extensions aka Slip between gears? On a N/A setup I usually go for 800 to 900 slip at Wot. My current convertor is a Circle D 4E 4400 and working good on a 383 ls1 N/A