circle track racing SC2

[MeSpdRacer]

ok so I have been reading the threads about some of the mods to do to this 1994 SC2 but many of them go back to being streetable. I don't need to worry about this because it is only on the racetrack. I will be deleting most of the exhaust (including egr system and O2s gone) and looking to get the stock header from an ealier model to 2 or 2 1/4 pipe to mid car. I am prob going to look for a bigger throttle body from a Geo Storm and not running an air intake system since it is only on the track. Does anyone else have tips or tricks for me? Thanks for any help!

[SaturnFix]

Mozez1975 is a dirt track racer.

[MeSpdRacer]

I will check with him but I am running a 3/8 mile asphalt track. Thanks for the reference though!

[AlexofNazareth]

Originally Posted by MeSpdRacer

I am prob going to look for a bigger throttle body from a Geo Storm and not running an air intake system since it is only on the track.

so what, youre gonna run just a throttle body and run no intake whatsoever?

[MeSpdRacer]

Originally Posted by AlexofNazareth

so what, youre gonna run just a throttle body and run no intake whatsoever?

lol sorry yeah I guess thats sounded a bit odd. I am running the stock intake with a Geo throttle body to try to get just a wee bit better performance

[proveniebam]

I'm running a 2000 SC2 on 3/8th mile asphalt oval.

[Speedrc99]

Wouldn't you still want to run the o2 sensors so the engine can run properly? I'd think that in itself would maintain your engine's initial performance. And a "straight piped" exhaust will kill horsepower.

[MeSpdRacer]

proveniebam- Awesome! hit me up if you have any tips or questions!

Speedrc99- The GM 1 wire 02 sensor does not do enough to hurt my performance, and why do you think it will kill horsepower with a straight pipe?

[klemsjasen]

Running an open header will hurt HP but in most cases a straight pipe exhaust is good for power at least that's how it works on V-8's

[Recycled Saturn]

Straight-piped exhaust won't hurt horsepower as long as it is the right diameter to improve scavenge. 2 to 2 and 1/4 is about right for our cars, go bigger and thats when you start to lose power

[PlasticCarsRock]

There is only one O2 sensor, and you certainly should not get rid of it... do you even know what it does...? What does "one wire" have to do with anything? With no heater, it takes a few more seconds to start working, but that's all; it's just as accurate as any other narrow-band sensor.

Also, blocking the EGR is also a bad idea. It won't give you any more power (the valve is completely closed at WOT), but it will cause higher combustion temperatures by not opening at other times, which will make pinging more likely (loss of power and risk of engine damage), as well as increasing your chances of burning an exhaust valve (fairly common on Saturns).

Open header vs straight pipe vs full 2.25" exhaust won't make much difference (if anything, the full exhaust will probably be better). At least run enough pipe to get the exhaust out of the engine compartment and behind the driver.

The mods you've talked about may gain you 3-5 horsepower (perhaps less). If you want to get any significant power increase, you need some way to tune: full standalone is preferred, but is very expensive, and requires you to know what you're doing... You're best bet is a WBO2 senor and piggy-back tuner (SAFCII is preferred, but certainly not the only option). Both are relatively cheap on ebay (used SAFCII, new WBO2).

Weight reduction is probably the most beneficial thing you can do--take out everything you can spare (spare tire, seats, a/c if applicable, trim, dash, stereo/speakers, HVAC system, etc).

Even with tuning, you will not see much more power than stock. If you want to make any significant difference, you need engine work: high compression plus cams will wake it up a bit...

[Recycled Saturn]

Originally Posted by PlasticCarsRock

Weight reduction is probably the most beneficial thing you can do

This, which is why I say don't run full exhaust. Run header to cat then dump it a foot or two after the cat. Getting rid of the muffler and extra piping will make a good difference in weight savings

[MeSpdRacer]

Wow over a year later after my original post and this thread comes to life! This is the second season I have run this car and ran this season on the rebuild on the engine. I have been running great with the setup I have. As for tuning I have been looking at it but if my plugs are burning very well and clean then will tuning actually help?


Many of you have seen what I have done on my car but for those that don't it is a 1993 SC2 full racecar (not street legal) Shaved .030 head, Geo TB, 4-2-1 header to 2" pipe down to a 1.5" dump behind the passenger seat area (as per the rules), totally gutted except for cage and my seat. Yes I blocked the EGR as most of my throttle is 50%-100% most of the time anyways. As for the O2 sensor, it is there and hooked up but again with how it is driven it I don't think it has enough control that it makes a difference in the way it will perform. Also have KYB-2 struts on H+R race springs for handling.

Going to redo my cage and stiffen the suspension, as well as new bushings all around for this season and see if I can pick up a few tenths of a second with handling.

[proveniebam]

How did you do in your seasons?



Next season will be my first ever race season. I'm driving a 2000 Saturn SC2. Bought it off the season's #2 driver. I had the chance to go into 4 heats and 3 finals. Limited seat time.

It's a strict street stock class. The car is pretty near the limit of acceptable alterations :-)

I'm wondering what sort of settings you're running.

1. Cornering.
I find it doesn't turn in sharp enough and pushes a bit too much on the exit for myself. I've done the

maths and I should have a stagger of 3.25". It currently has a stagger of nearly 5" (made up of mixing

14" and 15" rims, tire ratio and pressures.

It's a 100ft turning radius on a near flat 3/8 oval. Is that similar track to you? If so, what sort of

stagger are you running?

I'm running 20psi LF and LR, 40psi RF and 33psi RR.

2. Tires
Currently running Eagle GT 205/65/15 on right (wear rate of 300, track minimum is 280). Not certain of

lefts but they are on 14".

Looking at getting some Toyo T1R. What sort of tires do you run?

3. Power
I'm about 12hp down from factory.

Running an invisible filter :-). Copper plugs and NGK leads. Battery is suspect so will be changing

that over the winter. Looking at running a race battery (9lbs instead of 20lbs). Short of an engine rebuild (no money nor skills for that), what can I do to get more power and still remain visibly 'stock'.

You mentioned blocking off the EGR and running a GEO throttle body. What gains did you see/feel?

4. Weight.
Not much left to the car. Need to remove the air-con. Have you done that? Any gotcha's?

Also looking at removing the power steering but don't know how that will affect steering. Again you done

this?

Also I'm over the maximum L-R weight distribution. (56%/44%). Where would you put extra weight on the right of the car? I'm well over the minimum weight (250lbs+) but that's mainly because of me but I'm working on that.

5. Brakes
I've got horrible brake fade after 5 laps. Prevents me from braking late into the corners. Switching to an improved rotor (can't run slotted or drilled). This one has better cooling fans inside of it. Also going with EBC Yellow. Flushing the brake system will new racing brake fluid (dry boiling point of 595).

What have you done with yours?

I'm working with the tech director at the track regarding brake venting on the grounds of safety but it's not a easy discussion as yet. Did you do any brake ventilation?

6. Aerodynamics (yeah I know)
Some drivers 'sculpt' the inside rear so that the air doesn't go into the trunk. I don't think the gains outweight the weight penalty, but your experience?

I have problem with fogging with the glass and the lexan windscreens. Also glare on corner 3 in the early evening is blinding. Going to switch to metal mesh. But do you have an alternative suggestion?

7. Quick Release Steering Wheel.
This is more for safety than anything else. Have you done this mod? Do you have any good instructions on HOW to do it. Steering wheel okay. Quick Release unit okay. But how do you attach it to the steering column?

8. Lap timers. Any suggestions?

9. Rims
Steelies or Alloys? I know Alloys give better heat whicking but are there any down sides?

[PlasticCarsRock]

Originally Posted by MeSpdRacer

Wow over a year later after my original post and this thread comes to life! This is the second season I have run this car and ran this season on the rebuild on the engine. I have been running great with the setup I have. As for tuning I have been looking at it but if my plugs are burning very well and clean then will tuning actually help?


Many of you have seen what I have done on my car but for those that don't it is a 1993 SC2 full racecar (not street legal) Shaved .030 head, Geo TB, 4-2-1 header to 2" pipe down to a 1.5" dump behind the passenger seat area (as per the rules), totally gutted except for cage and my seat. Yes I blocked the EGR as most of my throttle is 50%-100% most of the time anyways. As for the O2 sensor, it is there and hooked up but again with how it is driven it I don't think it has enough control that it makes a difference in the way it will perform. Also have KYB-2 struts on H+R race springs for handling.

Going to redo my cage and stiffen the suspension, as well as new bushings all around for this season and see if I can pick up a few tenths of a second with handling.

Spark plugs can help indicate that an engine that is running very poorly (very rich, very lean, etc), but they are certainly no indication that you do not need tuning. Stock, the a/f ratio at WOT is very rich--close to 10:1. Most vehicles are like this (there is no feedback at WOT, so they run very rich to ensure that you are rich under all conditions). For maximum power, you want something more like 13.1:1. With your mods, you may be running a bit leaner than stock at certain rpms (depending on where your power band is), but no where near 13:1 (especially across the entire rpm range). Depending on what gas you're running, you may have some trouble with pinging at 13.1:1, so you may need to run a bit richer (you'll have to see what works with your engine). Regardless, you will certainly gain power with tuning (not a lot--you're not going to get a lot of power without forced induction--but tuning will make a lot more of a difference than bolt-on mods).

As for the O2 sensor. You are correct that it is not used at WOT (anything over like 70% throttle it runs rich, and a narrowband sensor cannot read rich ratios--it just knows that it's rich). However, whenever you're under 70% throttle, the air/fuel ratio is being adjusted constantly (several times per second) to keep it very close to 14.7:1 (it will swing back and forth between slightly rich and slightly lean).

Without the O2 sensor, it will default to a very rich condition at all times, which will foul the plugs, waste fuel, cause signicant carbon deposits, and possibly even wash down the cylinder walls with fuel (no oil=no lubrication=bad).