Dirt track dsm rookie needing help

[Dirt Eagle]

Hey everyone, I'm new to DSM and I decided to run a 92 talon 2.0 n/a @ my local dirt track. Rules are pretty simple there's no modding to pretty much anything but NO ONE FOLLOWS THEM. I'm getting whooped by cavilers and would appreciate suggestions on what I need to do to beef up performance. Im also having a problem not running high enough rpms in 3rd. So far all I've done is gutted, modified the springs, removed the air box & hollowed out the light hole to allow more air directly on the filter, bracing bars on the strut towers, adjusted the throttle, lightest cage possible. The car when I bought it had headers and an after market down pipe, came to find out that was illegal and to obvious to not change so made a stock header fit the down pipe and cut it off about 2 feet after the engine so header to pipe w/ no mufflers or cat.

 

[Teancum]

It's a bit involved. But delete the balance shafts. Less rotational mass = slightly faster revving and minute power gains.

 

[VtecvrsTurbo]

Do a non-turbo to turbo swap and tell them it's factory. I'm sure they don't check Vin numbers to verify. Can you even put dirt-racing tires on it?

 

[BogusSVO]

Up the compression, either by a piston swap, or find a Hyundai 1.6 head and a set of regrind cams.

I say regrinds so if they do look, it will look stock.

 

[Dirt Eagle]

@ the guy who said turbo haha they're surprisingly pretty in depth with their pre race inspections. One question i had was with a piston swap or injector swap, do you have to change the computer to account for the difference?

 

[1996Eclipse420a]

@ the guy who said turbo haha they're surprisingly pretty in depth with their pre race inspections. One question i had was with a piston swap or injector swap, do you have to change the computer to account for the difference?

Piston swap no, but for injectors you will need a way to control them. You can keep the stock computer and run a piggy back.

 

[Dirt Eagle]

Piston swap no, but for injectors you will need a way to control them. You can keep the stock computer and run a piggy back.

Ok so what if I bought larger injectors then installed a 2g maf (if so how many ccs)? would it even out? Running a piggy back would be too obvious for the inspections... also the claim rules are 1500$ and I dont want to drop an extra 500$ on a piggy back and then get claimed out of it

 

[eDeclpse92]

You said you cut the exhaust off two feet after the engine with no muffler/ cat; that will severely decrease torque, especially low end torque because you have the scavenging effect. I know only because I had to drive my 2.0 N/A to an exhaust shop with only headers and a down pipe. I really didn't feel any torque until I got into about the 4,000 to 5,000 RPM range, which sounds like why you are having trouble getting high RPM's in 3rd gear. I would put a muffler on or something that will create "back pressure" so you get torque back.

edit: http://www.carforum.net/exhaust-systems/9709-myth-back-pressure.html

This explains it perfectly what I am trying to say. It's a little reading but very informative. Good Luck!

 

[Dirt Eagle]

You said you cut the exhaust off two feet after the engine with no muffler/ cat; that will severely decrease torque, especially low end torque because you have the scavenging effect. I know only because I had to drive my 2.0 N/A to an exhaust shop with only headers and a down pipe. I really didn't feel any torque until I got into about the 4,000 to 5,000 RPM range, which sounds like why you are having trouble getting high RPM's in 3rd gear. I would put a muffler on or something that will create "back pressure" so you get torque back.

edit: No Specific Make The myth of "back pressure" - CarForum.net - Car Forums, Automotive News and Community

This explains it perfectly what I am trying to say. It's a little reading but very informative. Good Luck!

****************************When I had the muffler and reducer on previously i had the same problem. I could try it with some form of restrictor plate in the where the turn down bolts in at. How much should I decrease the diameter? Current exhaust is at 2 and 1/4 inches.*********************

 

[eDeclpse92]

What muffler did you have on it before? Have you checked compression lately or do any tune up to it (i.e. spark plugs, wires, oil...)? I would try a stock muffler to see if that would work before you spend a lot of money on it. Also, when you adjusted the throttle, what exactly did you do to it?

 

[Dirt Eagle]

I bought the car from a guy who put headers and exhaust on the car. No clue what was originally on it as far as muffler as his aftermarket muffler was just a fake muffler. Had to remove the headers and put stock exhaust manifold back on. Ported the manifold so that it would run smoothly into the aftermarket exhaust then a turn down at the end. However what ever exhaust pipe he put on is only 2 1/4 so it looks as if he just took out the cat and ran the same piping.

I haven't checked the compression but over the last week I put in 275cc injectors (up from the 240) and doubled the spark plug burn rate from 6 -> 9. The MAF is the honey comb design so not the nasty earlier maf. Oil of course! I ran prolong through while doing so to clean up. Also ran fuel system treatment when I first bought it.

The engine was a transplant and he didnt tighten everything up. The throttle was 10 degrees from being able to go full throttle so I adjusted the peddle stop and throttle cable to allow full throttle.