little help with FWD

[tgriffith]

Ive got a 89 cavalier that I just cant get to hook up consistently,,,,,60`s are only around 1.90.....as long as the track is great, so is the car.....soon as the track gets marginal, the car will spin.......any help would be appreciated

its a 173CI chevy,,,,24 tall slick,,9 wide,,,the rear is solid so there is little to no weight transfer

need some help if anyone has any ideas

thanks

tim

[Fred Popov]

Have you tried a ballast weight in the front? I would mount it as far forward as possible like in the front bumper. Also removing weight from the back should help.

[Steve Stockton]

Tim,

The more I think about it, the more I think it has to be something with the trans or converter. That is the only big thing that is different from when you had it before. I didn't have that many runs with it the way I got it from David with the stock gears in it to really know if it was more consistent or not. I just knew that it wasn't going to be quick enough.

The gears in it now are the same as what you had in before if I remember, but it has that Engineered Performance limited slip in it.

The same time that was put in the converter was done by some local guys here and they were all excited to try some new things with it. They were going to build me another one to play with, but nothing really happened with that. I know they did take the lock up part out of it, which they said took a LOT of weight out of it, and it ended up not stalling quite as high as it did before.

If you know what the converter was like in it before, I'd probably get another one of them and try it.

[art leong]

What tire pressure? Sounds like you have a lot of final drive ratio. I run a 20 inch tall tire and have 3.73 final drive. Plus the car is only 2600 pounds. Have you tried taking out some low rpm timing?
1.90 doesn't sound that bad. The best I had with my stockers was mid 1.80's running mid to high 13's
With my superstocker My best so far is 1.85 and the norm is 1.90 and that is going 13.1's

[Mark Yacavone]

Tim, that sounds like an awful lot of tire, height and width. Those tires will slow you down, all the way down the track. Not so much in the 1/8th though. Does it have a 3.73 final drive?

[tgriffith]

I have it VERY nose heavy and there is only about 1 inch travel in the back,,,,,,,,,,Im puzzled by a few thing on this car

1st-----it doesnt like the 20 tall tires,,,,,I have excessive spin and only about 67mph at the 1/8,,,,,the car seems to be quicker with the 24`s after the 60ft mark,,,,,,now Im sure that some is becasue of tire spin but with the 24`s,,,the MPH @ the 1/8 is nearly 70,,,,,,this also is at 2900lbs,,,,,,,,,the 1/4 MPH is @ 87 VS about 83 with the 20`s

now I know this isnt anything to write home about BUT this was at Bristol dragway,,,it ran 15.57,,,,,again, nothing to write home about but considering this is at bristol--.35 under is darn good for an actual stock motor with a cam

2nd---the 60 is way quick for the ET,,,,,,I could understand this IF this car was lite,,but it isnt,,,,,,,the digital MSD took a dump and with the stock computer, it isnt possible to retard the timing............I did try to find top dead center and mark it,,,,,threw a timing lite on it and it reads 40+ degrees at idle,,,,,,it goes to 50 at reving it up BUT I do want to POINT OUT,,,,this is very unreliable ( at best)---but it would explain all the short time ET and it not matching down track numbers

the gearing in the car ( I think) is only about an actual 3.40 or so with the 24`s,,,,,this is the actual tire size that came on the car--(215/60/14),,,,,,with the 20 tall tires,,gearing should be about 4.10,,,,,(.83% of actual size)---

After I had sold the car in 2002,,I had learned something I had did very wrong ,,,,,never thinking to try this again with a FWDer,,,put the info on the shelf and forgot about it,,,,

6 years later,,,I own the car again,,,,,so dug out notes and changed some things,,(about .30 worth),

last year at a test session,,,I was about the 5th or so pair out on a fresh sprayed track,,,,with the 20 inch tall tires,,,,,it slightly shuttered but had a 1.77 short time,,,,,,and needless to say,,,that was all of of that. Next pass, wouldnt pull out, and so on with the next 2 or so passes..,,,thats why I tryed the 24 tall tires,,,also with the 20`s on the only pass, it MPHed only 67......this was all at MM dragway in radford,,,,good track with no traction issues

with the 24`s ,,,,I had tryed 16lbs of air,,,,,.hooked fair,,,went to 18,,it was better,,,,went to 20lbs and seemed to hook better...all the numbers reflected it........the rims are stock and the 24`s, at the time, didnt seem to want to seat very well so I didnt go below the 16 mark with out drilling the rims for screws

examined the a-arms,,struts,,,the lower a-arms are alum,,,and are bent all to hell,,,,looked nearly warped

any help is needed,,,,tire pressure just may be way to high,,,,,,havent got any REAL info.....I had contacted the tire company and they said 22 to 24lbs,,,,,,,Im not going to swear to this but I think it says " do not inflate over 25psi"......whatever it was,,I got frustrated the tire company didnt have a clue

BUT,. over the years, in many racecars Ive learned that there is no "one size fits all" tire pressure number,,,,,I knew better even to waste time on the call, but was reaching....sometimes the biggest problem`s solution is the simpliest fix,,,,,,,

can I get away with about 10 or 12lbs of air on these 24`s ????..Is this my problem???.....the car performed absolutely awesome sat night UNTIL the track got marginal,,,,and that was all she wrote......


I appreciate all the help !!!!

[GarysZ24]

Originally Posted by tgriffith

Ive got a 89 cavalier that I just cant get to hook up consistently,,,,,60`s are only around 1.90.....as long as the track is great, so is the car.....soon as the track gets marginal, the car will spin.......any help would be appreciated

its a 173CI chevy,,,,24 tall slick,,9 wide,,,the rear is solid so there is little to no weight transfer

need some help if anyone has any ideas

thanks

tim

Tim,

I'm glad I saw this thread, because I race a Z24 Cavalier ('86) in NHRA's DF/S class (which is equal in index's to IHRA's EF/SA class), with (almost) the same engine yours has (mine came with cast iron heads and a lower hp rating). I agree with Steve & Mark about your not needing the spool with your automatic. However, I wonder (as Art did), what final drive do you have in your tranny. I run a nearly equal weighted car as Art's, and I have a 3.73 plannetary from a 4cyl J-car. That and an 8" converter from A1 (thanks Marv Ripes), that stahls to 3600 rpm, plus a set of Competition Engineering 3-way adjustable shocks, helped get my car to hook up great on good tracks even with the 20x8x14 MT slicks. Art, Steve, and Mark (amongst others on this thread), mentioned other aspects of your car that could be hindering your performance. I had a friend of mine help me ditch the pwr steering system (and the A/C as well). I gave up on the factory computer, and put an Accel Calmap in my car 13yrs ago, because I couldn't find any one who could burn performance chips that could give me the throttle response I got from a 350 V8 chip I tried from idle to 2400rpm (if someone could've burned me a chip that went to just 5600rpm's my car would've been a flyer, and I'd probably be running BF/S (NHRA's version of IHRA's BF/SA class off of the 14.95 index) still!!! For ignition success with your Chevy, I feel Performance Distributors makes a great (long lasting), coil that's high voltage and performes better for the dollar than the MSD unit I tried back in the 90's (sometimes you don't always get what you pay for). My tranny was converted to a non-lock-up to accomodate the converter, and my cam timing was retarded 3 degrees since the cam was so mild (.218 degrees duration). Although my car has the factory exhaust manifolds on it (headers for $1000 bucks...what happened to the Hooker header casting that created the headers that Linda Sherman used on her former Chevy Citation 173 V6 (now being enjoyed by the current car owner Randy Hyman)? Oh well, I have an X-pipe exhaust system that helps make up for the lack of the headers (somewhat), but if ever I can get a set of those on my car (w/o breaking my bank account), look out!!!

I'm surprised that 24x9" slicks fit in your wheel wells, because they don't in mine...thus the biggest tire size I can use would be the 22x8x15's, but I'd have to find some aluminum 15" wheels, and I can't afford them yet. I run my 20x8x14's on Cragar 14" wheels, at 20-22 psi. I'm also wondering if your car would grip better if you left the line just above idle (like I had to last weekend in Fontana, at the Jegs Pacific Sportsnationals), because I had tire spinning issues as well, but once I stopped stahling my converter, and did that, my 60ft's dropped by .13sec to 2.00-2.01 and a quarter-mile of 15.505 (which was -.395 from my 15.90 DF/S NHRA index), in crummy air of 3300ft @ a track that was 1100ft actual elevation (with a 5-8mph head wind)! I'd be scared to run as little of a tire pressure as you do with these smaller slicks, but if your engine tune, your tranny gearing, plus your rear suspension are more in harmony (if your cars back end drops when you take off, you need stiffer shocks to keep your car level...mine used to do that really bad, until I put the Competition Engineering shocks in it), then I think you'll pick up even more et., and have a better performing car...I wish you the best (from the west), with your Z from the east!!!

[tgriffith]

on my car, I have the back nearly solid so there isnt that notorous weght trans fer off the wheels also,,,,the power steering and other garbage is also gone,,,,I put an electric water pump on mine,,,,,took a moroso belt pump, cut the gear in half, mounted it backwards and it worked percect,,,I think the motor is mounted where the power steering pyump used to be,,,,it fit like it was made for it...its always an eye catcher if Im at a local test where there are other small cars (LOL)---it funny,,I have more lookers at that water pump than my other race car gets


"""I'm surprised that 24x9" slicks fit in your wheel wells, because they don't in mine...""""

they stick out about 1/2 an inch,,,,I was told that they were a littel tolerent with FWDs and Ihra dont have a problem,,,its close enough to strike up a good arguement (LOL)

on leaving at an idle,,,,the big issue I have with that is,,,,,Im really on new ground with counting the lites,,,,rite now, If I torque up to 2k and count 1--2--go on 3,,,,,lites are .03-.04,,,,,its nothing to write home about BUT considering Ive been a "see and go bottom bulb" racers for 25 years,,,,this is really something different and Im pleased.....its super easy to practice on the practice tree,,,,,Ive been told by other lite counters that is the place you want to be-----if I torque to 1500,,,its ..06 or worse-----I couldnt imagine what it would be at an ilde---In the beginning. I was hoping to block and leave on the second bulb,,,that netted a
--.350 and -.352 RED (.000 RT) ,,,just to far out to work with

the exhaust is dual individual that runs under the car and end about where the convertor used to be

are the comp shocks your using struts???
"

[GarysZ24]

Originally Posted by tgriffith

on my car, I have the back nearly solid so there isnt that notorous weght trans fer off the wheels also,,,,the power steering and other garbage is also gone,,,,I put an electric water pump on mine,,,,,took a moroso belt pump, cut the gear in half, mounted it backwards and it worked percect,,,I think the motor is mounted where the power steering pyump used to be,,,,it fit like it was made for it...its always an eye catcher if Im at a local test where there are other small cars (LOL)---it funny,,I have more lookers at that water pump than my other race car gets


"""I'm surprised that 24x9" slicks fit in your wheel wells, because they don't in mine...""""

they stick out about 1/2 an inch,,,,I was told that they were a littel tolerent with FWDs and Ihra dont have a problem,,,its close enough to strike up a good arguement (LOL)

on leaving at an idle,,,,the big issue I have with that is,,,,,Im really on new ground with counting the lites,,,,rite now, If I torque up to 2k and count 1--2--go on 3,,,,,lites are .03-.04,,,,,its nothing to write home about BUT considering Ive been a "see and go bottom bulb" racers for 25 years,,,,this is really something different and Im pleased.....its super easy to practice on the practice tree,,,,,Ive been told by other lite counters that is the place you want to be-----if I torque to 1500,,,its ..06 or worse-----I couldnt imagine what it would be at an ilde---In the beginning. I was hoping to block and leave on the second bulb,,,that netted a
--.350 and -.352 RED (.000 RT) ,,,just to far out to work with

the exhaust is dual individual that runs under the car and end about where the convertor used to be

are the comp shocks your using struts???
"

Nope, they're real shocks that one of my friends from the Denver, Co. area modified the lower mounting part of the shocks (bushing change or something like that), to allow it to fit in my stock housing. They were set at 70/30, and I had the option of 90/10 & 50/50.

[tgriffith]

on the computer system,,,,I havent took the dive for a stand alone system just yet,,,,,I may not,,,it just depends on testing Ive got to do,,,,,,,,,If I understand correctly,,the computer I have (ODB ) decideds what fuel curve to give based primarily on the water sensor so...... I borrowed a high dollar snap on scanner,,,,,unhooked the water sensor and hooked the wires coming from the computer up a 2 step module and started putting in different resistors to see what water temp it thought the computer was seeing,,,,,after i got a few done from 100 to 220,,,,,,I started making runs. I also hooked up an EGT guage to see how hot the exhaust was,,,,,,the reason I used a 2 step module was so later, I could put a swith on the shifter OR use an RpM activator to switch fuel curves in high gear......it seems to work fairly well,,,,,,,the one thing I did notice, at least on mine,,,is that its extremely consistent if and ONLY IF actual water temp is in the 125 range,,,,if it climbs past 140, it slows .10 and does not repeat, even if you try to run it at 140, it wont run the same thing twice,,,,,,,,,also ,,,it doesnt appear that weather bothers the car,,,,last run 2 weeks ago was 15.57,,,,,,,,,1st run this week was 15.57 with a 7 or 800 difference in adjusted altitude,,,,,,,,the egt was reading 1335@ the 1/8 and 1475 or so @ the 1/4 mark,,