Improving Racecar

[RacingMan]

I have raced asphalt oval for several years in a dodge shadow with a 2.5 non turbo engine. I currently have the head shaved 30 thousands and the flywheel shaved. I am looking to pick up a few more tenths on the track.... What other ways are there to either improve performance or help traction on the car?

[cordes]

While staying N/A? Going to a turbo would create a whole new world of power for you at a relatively low cost.

That said, there are several DC cams which were offered for the cars. IIRC there was also a header. You could have the head ported too.

I'm not exactly sure what type of racing you are doing so I'm unsure as to where you would be best off traction wise. The oval makes it sound to me like tracking down some Koni struts and shocks would be a good idea.

Welcome to the site. :)

[BadAssPerformance]

Welcome to the forum!

As Cordes said a turbo would add a ton of power capability BUT I am guessing they do not allow those in your class?

If you can provide some more information on your build and what the rules limit, we should be able to help you.

[RacingMan]

sorry, our class is limited to fwd, 8 valve 4 cylinder, sohc non turbo. The car is supposed to be stock but they let plenty of gray areas in so everything is always seeing how far you can push it until they don't allow it. I was thinking about maybe a shorter shock on the left rear? I don't even know if that is possible but it was a thought. I know I can heat and collapse the left rear spring.

[RacingMan]

I did remove the balance shaft and it really gave it a lot of power. Can I block off the heater hose going into the intake and just make it go strait to the head or would that mess something up with the computer?

[cordes]

I did remove the balance shaft and it really gave it a lot of power. Can I block off the heater hose going into the intake and just make it go strait to the head or would that mess something up with the computer?

You don't need the heater hose going to the intake.

[RacingMan]

Ok so would I block it off coming from the water pump or just make it got straight to the thermostat and head?

[cordes]

Ok so would I block it off coming from the water pump or just make it got straight to the thermostat and head?

I take mine from the water box at the head to the water pump. I have read that the circulation is necessary.

[RacingMan]

Alright I will try that.

[RacingMan]

I had a question to anybody who has an idea. I put the engine in my car and have all the timing set right. The car will run really good as long as the temperature sensor is unplugged but when it is plugged in the car starts to miss fire and like it floods out when i press the accelerator. Is the sensor bad?

[turbokid]

Yes most likely.
Have you set the ignition timing with the sensor unplugged?
You can play with the ignition timing. A tbi car tends to run better with a little advance

[t3rse]

Very possible. If the sensor is sending a too cold signal the computer will add fuel...in the same if the sensor is sending a too hot, as in overheating, the computer will add fuel as well. Does it do this with the car warmed up? Cold start enrichment doesn't last very long is why I ask, but temp adjustment is always made. I should note that my comments are not based on the mopar computer, because I don't know that it actually operates in the manner I described, but my experience with standalones leads me to assume all fuel injection compensates in this manner for extreme temperate readings. Also forgive any grammar errors i may have: just got my eyes dialated and I can't read very well at the moment.

[thefitisgay]

You can play with the ignition timing. A tbi car tends to run better with a little advance

timing adds lots of power specially if you are running in an rpm window be careful with it though you could melt a piston quick

maybe a 2 piece and mpi would help out

[sy2206]

What other ways are there to improve traction on the car?

Is a limited slip differential allowed in your class?

[RacingMan]

I did set the timing with a light and advanced it to 15 degrees. It has a lot of acceleration and runs great as long as the sensor is unplugged. I am going to try another sensor tomorrow. I haven't tried to let the car warm up to much yet to see if it starts to run right. I did add falken rt615 tires and some better shocks. I am going to add some camber tomorrow as well. I'm not sure about the slip differential but I doubt it.

[jl93sundance]

are you currently tbi or carbed?

[RacingMan]

currently tbi

[ATaylorRacing]

What limitations are there on rims and tires? I can get you some 0 offset 16x8 rims with 4.5 inches of backspace...this will allow a lot more room for a wider tire around the strut, but everything is pushed way out towards the fender well openings...can you open the fenders up? Can you run a DOT drag tire with lots of tread like this one?

http://www.tirerack.com/tires/tires.jsp?tireMake=BFGoodrich&tireModel=g-Force+T%2FA+Drag+Radial+2

35 time NHRA/IHRA Drag Race Champ
05 SRT4 / S2 / 12.87 @ 110 / DOTs
05 Mustang V6 / wifes / 15.17 @ 92 BONE stock
96 Geo Metro / 3 cyl - 1 ltr - 55 hp / 19.84 @ 66
84 Horizon / used to run 13's no power adders

[RacingMan]

Here are the rules of the track I race:


1980 or later American made front wheel drive only (Ford,
GM, Chrysler).
Maximum wheel base of 105”.
Completely stock for that make and model (body, frame,
suspension, steering, pedals, brakes, etc.)
No bracing or body modifications.
Stock ride height for car being run.
All insulation must be removed.
Stock carburetor/fuel injection system for that make and
model.
No turbo or super-charged systems allowed.
Factory stock air cleaner system with no modifications or
removal of sensors.
4 cylinder only. No quad-4’s. Engines must remain stock with
a 0.020 maximum allowance of clean up of head.
All electrical componenets must remain stock for car being
run.
No dual overhead cam engines allowed.
Power steering belt and pumps may not be removed.
Battery must remain under the hood in stock location and be
well secured.
Passenger cars tires only. All four wheels and tires must be
the same and be stock for that make and model of car.
Right front must have oversized lugs for safety.
Low profile or performance tires are not permitted.
Stock wheels, stock suspension in stock position.
Camber may be adjusted as much as stock adjusters will allow
up to 3 degrees maximum plus or minus on front wheels and
up to 2 degrees maximum plus or minus on rear.
No alterations or camber bolts allowed.
Stock transmission and differential (no locked differential).
Broken windshields may be replaced with 3/16” lexan. No
plexiglass.
72
Removal of AC condenser and pump is allowed.
Revoval of inertia switch is allowed (fuel shut-off Ford).
Removal of rear seat allowed, but must cover rear firewall
with aluminum or steel sheet metal.
Electric engine cooling fans may be wired to run constantly.
No adding weight of any kind is allowed.
Minimum right side tire air pressure will be 25psi before race.
UCARS are not required to run track gas and may use pump
gas. No additives.
Quick release steering wheels may be installed. They must be
properly installed and be acceptable to track officials.
UCAR TIRE RULE
Passenger car tires only.
14” and 15” tires only.
All four tires must be the same size with similar tread pattern.
All four wheels must be the same size and style.
No low profile or performance tires allowed.
No tire lower than 60 series allowed.
Only Q-R-S-T-U and H speed ratings allowed.
Only tread wear ratings of 200 or higher allowed.
No altering of tread pattern by any means allowed.
No altering of tire compounds by any means allowed. No
armor-all, tire dressing, tire conditioners, softener, etc.
No removal of tire name, size, or rating by any means allowed.
Tire must have brand name, size, and ratings present.
No tires will be allowed that do not have tire speed rating and
tread wear numbers present.
Speedway and/or officals reserve the right to ban
any tire if deemed a competition advantage or unsafe.

[contraption22]

Find an Omni. Its lighter!

[WLKivett]

80's Imperials came with 14" aluminum wheels that looked like steelies. They have wire wheel covers

[RacingMan]

Omni's haven't had much luck at our track so far. They have a hard time handling in the corners. I have to many shadows to switch models. You are right with lighter is better. I need to try to get some weight off of my car and get it lighter. That would help a lot.

[RacingMan]

would the Imperial wheels fit a shadow?

[PBODY]

The wheels should fit your Shadow.

What about running a spacer under the throttle body?

Or is that not allowed?

[RacingMan]

I haven't heard of anyone running one. I don't know if they could say anything if you just had two throttle body gaskets.

[WLKivett]

You may want to look at the handling more than the power..... If you can mix and match stock parts you could try and get some some springs off a Shelby CSX. They'd be stiffer than standard shadow springs and lower the car about an inch.

[RacingMan]

That's a good idea. Are there front struts better too?

[135sohc]

Unless you find NOS ones, anything used is going on 20+ yrs old and worn out.

[Vigo]

Yeh, i wouldnt worry about the struts difference because all the stock stuff is soft enough that any good strut is going to work with it.

There were 3 factory front springs that i know of.. base, mid-level, and shelby stuff. Those are sort of my names for them, not anything official.

i think the 3 rates are something like 95 lbs/in, 120, and 145.

The stiffest rear springs are 125 i believe.

putting stiffer springs in the back will definitely help, and might help the front.

You can find the stiffest factory springs on anything that says shelby, including shelby daytonas, along with some special packages such as the Daytona C/S package and AGS packages, iirc. Ive been able to find many of these cars in the yards over the years, though it is drying up slowly now. I used to pay $9 for a coil spring, so i always picked em up because i have a bunch of cars.

There are also bigger front sway bars, and the rear axle is a torsion beam that has different diameter bars welded into it depending on trim level. You could put the highest level springs, swaybar, and rear axle in the car and it would look totally stock.

When my aries was TBI i dropped over 2 seconds off the 1/4 with it, but most of that was in a 5spd swap.

What rpm range are you running in most of the time? Its possible you could gain some power in certain ranges by advancing or retarding the cam. You can use offset keys to do this, and its invisible. The trick is finding the keys. Or, there is a factory cam gear that will retard the cam 4 degrees and is a stock looking piece.

You can also use some alignment shims behind the brakes on the rear axle to help the car turn. Are you turning left? A little toe-out on the right rear might help, and it would also be invisible. You could probably even do this with washers if you had the right thickness.

[RacingMan]

so the idle problem ended up not being the temperature sensor. I changed it and the problem still persisted. I decided to check all of the wires near the throttle body and noticed that after the engine change one plug wasn't plugged in. It went to vac on the EGR valve. I had to change pieces because the engine i put in didn't have a plug in. Long story short it is running really good now with no misfires. I need to recheck the timing and set the toe out but I am ready for practice this weekend.

[RacingMan]

I took the car to practice and it only made a few laps before knocking.. Guess the engine wasn't able to handle the high rpms. I put another one in and believe I have it ready. I gutted the power steering by removing the parts and fins inside of it and now just the pull free spins. Just wondering if anyone has a clue to how much horsepower this will give me or if I made a mistake by gutting it.

[Vigo]

I dont think its a mistake because its easily reversible with a $10 pump from the junkyard. Im guessing itll free up 5-10 hp at high rpm 5000+.

[bfarroo]

Have you done any baffling in the oil pan? These engine are notorious for oiling issues with high cornering forces. Also I switched my Shadow over to the PT Lifters with shims and the car runs much better after long high RPM runs. I do oval Ice racing in the winter with a Turbo Shadow. I use to have problems with the oil getting aerated and the lifters collapsing. The PT lifters have air bleeds to let the excess air out. Some think they have a taller collapsed height which also may add in the amount they can collapse. Are you running a auto or manual?

[bfarroo]

I'm not sure if it will help but you could add a second factory spacer under the TB.

[shackwrrr]

find yourself a spirit with the flex fuel package. They pretty much have everything the turbo engines have but are NA. They are multipoint fuel injection and have bigger injectors. You could have a computer done up for it and have some good power coming from it.

[RacingMan]

I haven't done any baffling but I defiantly know what you are talking about with the cornering and needing to keep the oil near the pump. Someone told me to restrict the oil journal in the head to give it higher oil pressure but I wasn't sure about doing that. I thought about just adding another throttle body gasket to make a small spacer. Our first race is this Saturday so hope all goes well and I will let you all know how I finish.

[Mopar318]

I currently have the head shaved 30 thousands and the flywheel shaved.


a 0.020 maximum allowance of clean up of head.

Looks like your already illegal.:lol:

[moparman76_69]

Looks like your already illegal.:lol:

Its not illegal if you don't get caught. :eyebrows: Everybody bends the rules in circle track.

[RacingMan]

moparman76_69 is right on... You have to bend the rules to what isn't so easy to check. If you say have a cold air intake right out in plain view they don't have to look much harder. So the rules are not like a book- black and white. There's a whole lot of gray.

[RacingMan]

The car ran good and I finished 4th out of 20 some cars. I could run the same lap time with the top 3 but I couldn't gain any ground on them. My car seems to be lifting the left rear way up when i corner. I thought about lowering the left rear spring.

I also wanted some feedback on finding a shorter shock just for the left rear. I saw that a 93 dodge caravan has a shorter shock with 11 inch compression and 18 extension. Anyone know if a shorter shock would help? Also what is the shortest I could use that would fit a shadow?

[mrbee64]

shove a rag up inside the right rear shock..this will make a bump stop. leave a tail hanging out so you can remove it if needed. This works on cars with front shocks can't see why it won't work on the rear.

[thefitisgay]

ratchet strap the left rear shorter?

[moparman76_69]

The car ran good and I finished 4th out of 20 some cars. I could run the same lap time with the top 3 but I couldn't gain any ground on them. My car seems to be lifting the left rear way up when i corner. I thought about lowering the left rear spring.

I also wanted some feedback on finding a shorter shock just for the left rear. I saw that a 93 dodge caravan has a shorter shock with 11 inch compression and 18 extension. Anyone know if a shorter shock would help? Also what is the shortest I could use that would fit a shadow?

Sounds like you need a stiffer right front spring if your lifting the left rear shorter shock on that wheel won't help it'll make it lift worse. When you enter the corner hard all the weight transfers to the right front. If you can get away with it you can stick a "rubber" in the right front spring to stiffen it up.

Is the car pushing or does it feel neutral in the corner?

[Vigo]

Well, he said lowering the spring, which i assume means lowering the car, not putting a shorter shock. If you lower that corner you put more weight on it which means it lifts less when presented with the same force.

[moparman76_69]

If you lower that corner you put more weight on it which means it lifts less when presented with the same force.

True but if you look at what I posted it says shorter shock which will only reduce the extended length which will make it worse not better.

[RacingMan]

The car is really loose and the rear is trying to pass the front. Which is good because I like it that way. I just am trying to limit the body roll and save the right front tire. I blistered a new tire in just a few laps.

[moparman76_69]

Ok I have a copy of a book call "The Front-Wheel Driving High-Performance Advantage" It doesn't cover circle track but does cover road racing so the setups would be similar just you're only turning left.

Anyway, it talks about running the rear twice as stiff as the front and running the front soft so you get more body roll and keeps the car from immediately transferring all its load to the tire. It also talks about running 3.5-4.5 degrees of neg. camber and toe out on the front.