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Topic Review (Newest First)
11-04-2012 01:02 PM
Fang16
Quote:
Originally Posted by F-BIRD'88 View Post
I cannot read it. Please type in the data.

Hate to be critical guy, but your lack of attention detail is probabily 90% of the cars problem.
Hard to get to the root of the tuning problem when you dance around it and take the long hard route with
"politician spin" (half truths, bad facts, spin on data, etc)

I hope you take this in the constructive manor, it is intended.

One looks like 89.15MPh and 100.33 mph (1000 ft) 107 in the 1/4"
If I 'am reading that right:

This indicates the car is dieing progressively as it goes down the track
starting at or just before trhe 1/8th point and gets progressively worse.
power loss.

Once clear shows you let off the gas before the end.
To get a valid accurate MPH at the strip you must keep your foot on the gas 66 feet after the finish line.
Or you will get a low inacurate MPH.
The MPH tells the horsepower. The track is much like a dyno test but requires consistant driving.
The more time slips the better. Post only your data, not the other lane..

the car has the potential to run 113.32 mph. once corrected and will
run faster and quicker when you get BIGGER better carbs, mufflers etc.
easy 11's @115-117MPH when fixed up.
I agree with the inconsistencies. I realized after my last track time that I need to forget about the reaction time and concentrate on being consistent with how I launch, shift etc. You’re right about letting off, did that before I was through the traps. Have only made 9 runs after a 47 year absence so have a lot to learn. My main concern at this time was getting an idea of what needs to be done to get the engine to perform which I have now thanks to the suggestions made by you and the other guys. Oh yes! I know you meant it as constructive.
Rt: .1982
60ft: 1.7979
330 ft: 5.1348
1/8 et: 7.9061
1/8 mph: 88.15
1000 et: 10.3382
1000 mph: 100.13
¼ et: 12.4147
¼ mph: 107.53
11-04-2012 12:30 PM
Fang16
Quote:
Originally Posted by F-BIRD'88 View Post
A good suggestion...all these areas need to be looked at.
I've lost a few vavles in the past in cars and motorcycles. Doesn't seem to be any vavle float. Of course if they're not hiting anything. hee hee No really, don't seem to be.
11-04-2012 11:11 AM
Fang16
Quote:
Originally Posted by F-BIRD'88 View Post
Some times you get a funky MPH on drag time slips.
I remember a long time ago my friend got a 130MPH on hs 12sec car once.
It does happen.

But from your numbers the car is wanting to go 113 Mph in the 1/4
but something is killing it.
What about the 1/8th mile data? what is the variance in the 1/8th MPH?
88.83MPH is a good 1/8th mile MPH (its at least in the program)
The car starts out well but flattens out at some point about 1/2 way down.

101 MPH sucks for that car. (there is a problem)

any 1000ft data? All this stuff can be analyzed. You definatly have a top end power robber, to find.
The air fuel ratio needs work. (those carbs suck on a T ram anyway)
(carbs-fuel system, (volume, limitiation))
could be spark scatter/crossfire. (ignition cap ionization, usually from too large plug gap and or too hot a coil, or poor cap/rotor phasing)
could be a fubared transmission or torque converter (no top end MPH)
could be a valvetrain issue.
The mufflers definatly suck- you will see from testing
once you find the other cork(s).

Your car should be running like a raped ape, but its got a problem.

Can you post the complete data from some time slips?
Per ur suggestion in another post I used irfanview to scan, resize etc trying to get this pic readable. Sure you can manage it. lol Seems I told a lie, or "misspoke" as the politicians say "lol" as u can see by the time slips. Hoping next year the track can afford some ink for their printer. hee hee Really apprecate your help.
11-04-2012 10:43 AM
E.Furgal not fer nothing.. but could you all be barking up the wrong tree..
the one lonely 107mph is telling me.. it might not be intake/fuel related, and yes I could be wrong.. as I'm here and his car is there..
but are the valves floating.. just a friendly guess..
11-04-2012 06:17 AM
Fang16
Quote:
Originally Posted by F-BIRD'88 View Post
In a previous thread you said the car ran 107MPH.... Which is it 101 MPH or 107 MPH?
That was a one time thing. Never happened again. Turned a lot of 101's.
11-03-2012 06:55 PM
vinniekq2 what happens to your fuel pressure? 13.5 is lean but acceptable,just wondering if the fuel volume is adequate? low 12s at 101 is not very good horse power wise but very good et wise.Its acting like a very small engine for mph but et indicates it jumps off the line? whats your 60 foot time? cam specs? time on valve springs?
11-03-2012 05:22 PM
wwilliams181 I'd put a couple of nitrous plates on it and let it eat!
11-03-2012 04:06 PM
Fang16
Quote:
Originally Posted by F-BIRD'88 View Post
I would expect a lot higher MPH ( limited choked off horsepower) and the dyno shows that too.

Those tiny carbs that were never intended for a tunnel ram are killing it.
650-750 double pumpers or two 750 edelbrocks. There may be more,other issues killing off the top end too.
Peak engine HP should be in the 6500-6800rpm range.

Chassis dyno can show issues with trans converter, trans internal friction, trans High gear clutch/hyd fluid issues
common to th700r4's at high rpms. Tires can have a big effect on Chassis dyno HP. Exhaust system Flowmasters are one of the worst mufflers. Cars always run faster when these are uncapped. Again tunnel rams need to breath deep. Restricted carb and restrictive mufflers kill it.

correct valvesprings? fuel system flow volume @ WOT.

Start by ditching those carbs. A tunnel ram needs to breath deep.
Your car should be running 115MPH ++ I build junk krylon rebuild 355's with ported 305 heads that run faster.

Lock out the distributor mechanical advance . It will idle and run a lot better.
You are missing at least 10 MPH. what is the 1/8th mile ET and MPH? 60ft?

For sure ! I knew that 4200 wasn’t right. Lol The tranny is a maddog build with vette servo etc, 3500 stall from maddog also. I rarely get into third on the track. M/T says not to run their tires after being on a dyno so I put some 15’s on that I had laying around. They were a good 2” shorter in height
The flowmasters are the 10 series, still bad? What would you suggest? Comp roller springs, lifters, rocker arms. Running 6 lbs fuel pressure with ele pump and ½” lines. Doesn’t feel like it’s starving for fuel but may be right on the verge? Will uncap the headers at next track time.
MSD 6al and distributer, still lock out the advance? Mechanical - no vacuum advance. To be sure, ur talking bout locking it to full dist advance? What should total be, at what RPM? 2-3 degrees under kick-back?
1/8 mile: 7.8578 @ 88.83 mph 60ft. 1.8 then it took 4.5 seconds to ¼ mile ! LOL
Been away from it for a long time, read a lot of your responses and I’m impressed by your knowledge. Thanks for your help!
11-03-2012 02:10 PM
E.Furgal 900 cfm is a choke with heads that even ported by a pro will be hard pressed to use 900 cfm.. anywhere near the rpm that his power flat lines..
the heads ports are the choke, and the huge intake area isn't helping that fact
I'm willing to bet it'll make more power everywhere with a single plane and one 450 than whats on it now..
then put a 650 on that single plane and make even more..

tunnel ram 4500-8500 rpm..
way to big..
11-03-2012 01:47 PM
E.Furgal not so sure the carbs are the issue...
2 450's is more than enough...
I'd point finger at the camels

and maybe lack of signal to the carbs.. (ie the intakes to big for those heads..)
11-03-2012 12:57 PM
Fang16 Yep, degreed cam at 4. The carbs are race 450's. Kind of thing I'm running out of carb.
11-03-2012 12:00 PM
Greg T Looks to me like it's running out of lungs.



.
11-03-2012 10:13 AM
Fang16
2x4 tuning - Flatlined chassis dyno

Had my 355 sbc 41 Willys on a chassis dyno. Didn’t do any tuning at the dyno, just wanted to see how my ear n eye tune was doing. I was somewhat surprised to find the read out flat lined at around 4200 RPM. Max power is 319.4 and torque is 389.8. It runs good and turns back to back 12.4s @ 101. Specs are: 355 sbc, 11:1, comp cams xr292r kit, roller rockers etc, ported 2.02 double humps, 2x4 Holley 450 cfm, mechanical secondary’s on a Wieand tunnel ram. 1 5/8” gasser headers down to 2 ½” flow masters. Full advance 36 degrees @ 3000, 700r4, 390 gears, M/T et street radials at 30”, Race weight is 3257 lbs.
I’m thinking I need some tuning or even bigger carbs, maybe 650 double pumpers as I feel it wouldn’t have enough vacuum to run vacuum secondary’s at the track. I’ve included a pic of the dyno sheet and as you can see the a/f ratio looks pretty good which is what throws me off and leaves me at a loss as to what to do.
I ordered a LM-2 meter to help with tuning, which raises a question, with a true twin exhaust (no X pipe, etc) is there a need to take readings from both exhaust? Thinking about getting there clamp on exhaust pipe tool also, the one that slides into the tailpipe. Is it needed?

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