IMCA stock car HELP!!!

[drivingexcitement]

I am having huge problems, its been about 25 straight weeks and it feels like I have no passed a car or even competed for a win. I have a professionally built car, professionally built engine, all top of the line parts, I have searched and searched for jujnk parts, bound up springs, tested shocks, springs, put new wires, coil, cap, msd box, different distributors, tach, fuel pump, lines, different carbs, different engines, cams, everything, I am at the end of my rope. Sometimes I dont think I am fighting a chassis problem sometimes I think its ignition or something holding the engine from peak performance. Its not like I am a rookie, I have won quite a bit and always competed for wins.

Here are some details about the car

ride heights lf 7 rf 7 1/2 lr 7 1/2 rr 8
springs lf1000 rf 1100(have tried 1200) rr200(175 sometimes) lr 225 rear springs are 13"(16 wont fit)
shocks lf 4040 rf 3050 lr5030(sometimes 6010 4010) rr 3030(sometimes 4040) all professionally rebuilt and valved
front wheel weights the rf is about 5# heavier than lf, I have tried 130# bite, usually around 150# but have been all the way up to 300#

the rear end is straight and it sits square in the car, the rr trailing arm is pretty close to level with the ground, the lr is down as far as i can get it.

54% rear
52%cross
52% left

1 1/2 stagger in the front
1/2 in the rear

I dont really know what I am looking for, like i said sometimes i think something is holding the engine back, sometimes i feel its chassis. the reason I feel it could be something holding the engine back is normally I would run a 543 or 537 gear and turn the engine about 6200(when I was winnning), and now I have a far superior engine(and other parts), and am using a 567 gear and only turning 6200(which is all i can get out of it) i get beat off the corners terrible, I get beat into the corners, I get beat everywhere, except the start of a heat race and can pull away for the 1st lap and than fall to last by half a lap.

[stock car driver]

Find a chassis dyno near you and get your car on there and rule out the engine first.

Ive heard of a improperly tuned motor being as low as 140 to the rear wheels in a IMCA stock car, that same tuned motor made 250 to the rear wheels, jetting and timing and lash were all off.

jj

[bushracing67]

check your tire pressure gauge, i just found my 12 month old gauge was reading 3 pounds high... wasted two weeks on the worst handling car i have ever dealt with, it was just undriveable, couldnt get in the corner, wouldnt turn in the middle, sometimes it would drive off, sometimes it wouldnt.... it was just a piece of (not a nice word)(not a nice word)(not a nice word)(not a nice word) lol

[drivingexcitement]

I will check the tire pressure gauge.

As for improperly tuned engine, I have had 6 different engines in, one of the engines I borrowed from someone(and the carb and distributor), and it was terrible slow in my car, I gave it back to them and they ran it up front. The terrible part of that is, I always beat that other car/driver. I even scaled that car. Now I cant get out of my own way. My last 2 engines have been professionally built, I have had the builder set rocker arms, timing, jet it for me at the track(3 plug checks in one night just ot make sure it was correct), come home re-check lash, and it still slow, checked header temp, ohms on wires, i have checked spring pressure, compression, and everything seems to check out great.

Is there any way possible it could be a brake problem. I have removed all the rubber bushings in my calipers, my caliper mounts on my rear end are straight. I can have someone sit in the car push the brakes, and I can go around and spin the wheels. Is it possible that I have a line collapsing while using the brakes at the race track, or anything like that. Something I can't find at the shop, or something I am missing.

[ToddSmith16]

You may have a bad ground or some sort of blockage in the fuel line. Do the plugs look lean? ...or Sticking/binding brakes!

[drivingexcitement]

I have checked all the grounds, made sure engine was grounded, checked battery ground, ignition ground, they are all pretty good. the engine sounds great, seems to run good, the car is just really lazy,(and inconsistent). I don't have a miss, it doesnt sputter, pop bang or anything. Plugs have been checked, they are not lean. Over the last 25 races I have put on new fuel line, filter(its installed correctly), new fittings(the expensive an fittings), all the way from the tank to the pump, I have put new fuel pump, new lines from the pump to the carb. The old line and fittings are on a friends car now(who is a rookie and he can pass me with 2nd rate parts). I have also tried 2 msd distributors, 3 coils, new moroso wires, 3 different caps, a new rotor, new msd box, new tach. Nothing has improved the car other than the msd box which I picked up 500rpm(old box tested weak). I have lightweight driveshaft, light weight gears, gun drilled axles, I have tried 2 different powerglides(for no reason). I have all my wiring soldered together.

Like I said there isn't a miss, no popping banging, it sounds great in the shop, it sounds good at the track, plugs have been checked, lash, compression. But something is holding my car back. Im about to put new brake lines and calipers on it.

[drivingexcitement]

How can I check sticking and binding brakes? I have put the car up on jack stands, put someone in the car, spun a tire, had them push the brakes and let off, than check to see if the wheel spins freely again. I have done it to each tire and don't see anything out of the ordinary. Could it be that once i start using them at the track and they build up heat they could bind than???

[ToddSmith16]

.....is there any discoloration to the brake fluid? Heat could case it, a pinched line, etc.. Any of the brake lines near a header or exhaust(extreme heat build-up)? Is there one wheel more than the other that has brake dust build-up? Check the pad thickness and see if one is wore more than others. Have you disconnected tach while racing or hotlaps? What type of tranny are you running? Auto or manual, Bushore, saginaw, etc..?

[26-62 racing]

Transmission

Is it an automatic with a converter? The impeller fins inside of a converter can be damaged, loosing the fluid drive or torque multiplication of the converter. Which could cause the problem you are talking about. Just a idea.

[SRXSRULE]

Go to a chassis Dyno!!! You will be testing everything under load just like on the track.

You can find problems like a brake hanging up, Rear end bearing(s), Fuel system problem, Electrical problems, trans problems.....etc the list goes on and on.

Bottom line is find out the HP going to the rear wheels. If its inline with what the engine should be putting on (The chassis dyno operator will know) then you can rule out the entire powertrain and start looking at the set-up.

Eric

[drivingexcitement]

The brake fluid looks good, no discoloration or anything. Brake lines are as far from headers as possible. I looked for a pinched line, or anything out of the ordinary, could find anything. The rotors look good, no blueing or anything. I have tried 2 different tachs,bought a new one 2 races ago, same thing. Tonight I took my drive plates and hubs off and checked the bearings, they all looked good and moved freely. Axles look good, I can spin one tire and the other one spins also.

I am running an automatic(bushore). I have tried 2 trannys, both same result. No convertor just the coupler.

I do have a chassis dyno scheduled for tomorrow. I should have done this along time ago instead of just buying parts and throwing money at it. I have extra distributors, caps, rotors, wires, coils, carbs, spark plugs, a gear, fuel pumps. I don't know what else to take. ANy ideas?

[stock car driver]

If a brake was locking up it would likely be very evident when you pull off the track, smoke on that corner and or glowing rotor etc.

If the mounts are bent at all it can not let the piston back in the caliper when hot.


I check jet, timing, lash on the dyno with my motors in that order. Then I do other carbs and jet them.

Depending what air cleaner you run you might want to try a different type vs. it.

[dirt2]

Have you checked the vent on the fuel cell?
If you have the long in line filter with the cone
screen filter is it in with the open end forward
to the pump? If you run headers are they four
tube off the flange to collector or does # 3&5
connect just off the flange then go to the collector
as one tube? If so try another set,seen this problem before.
dirt2

[Dirtrunner35]

Enough axle grease ? Maybe it's trying to lock up?

[stock car driver]

An issue that I had that plagued me on the track only this season was my ford solonoid had broke free from the top in a roll over and was grounding out internally, it took about 3-4 laps to get hot enough to matter but it then lowered my ignition power enough that my plugs would foul and my car had no power, it sounded terrible and was very obvious when this happened, it was really hard to diagnose and caught me by surprise since I support both cables going to and from it right next to the solonoid because this has actually got me before...

[moving violation]

Did you ever compare your timing light to another? Maybe yours is off a little and its not timed where you think it is.

[stock car driver]

Well how did the chassis dyno go yesterday?

Lets hear some numbers? Whos chassis dyno did you use?

[drivingexcitement]

298.63 hp@4750rpm at the rear wheels, idk remember the torque#, left the print out in the shop.

Had a fuel problem, I was holding 8# pressure on the gauge, but the fuel bowl was trying to run itself low on fuel. The 1st pull the bowl dropped 3/16 of an inch. Changed jetting and float level. They ended up going down2 jet sizes each pull, going down 8 jet sizes total(than back up 2 sizes). Also went from 34 timing down to 32(made more power and didn't fall off as much).

I guess my next question is, how many people take their cars to the chassis dyno? And how does everyone jet their carbs? I always jetted it by getting the car up to rpm under load(at track), and shutting it off, etc etc, and than ready the plugs? Is that not correct anymore? And for the people who do use a chassis dyno...do they trust the computer? I would hate to melt my engine down

[stock car driver]

Is that on mid states dyno?

I trust the dyno we put the exh sensor on a tube and clamp it to my header one one side. Weve checked it on both sides with the same result.


If you were that rich you should have felt and heard your car running poorly, really poorly.

[stock car driver]

284-294 hp for me on the chassis dyno I use in Lincoln Nebraska

Mid states dyno seems to read 30 higher than mine, I know a lot of guys that use it and have compared their dyno numbers and motors with mine over the years.