Originally posted by Cyberjay:
[QB] .... we did try to heat up the left rear spring, but we found that we had quite a push in the turns at our local 1/4 mile mid banked track, but it worked well at a 1/2 mile flat track.
The front springs can be cut, and supposedly the rears can also if you are careful. Heating, to deform springs, isn't suggested unless you retemper them. You'd be better off cutting them to achieve the desired ride height but don't do it until after all the wgt removal, and better to cut too little than too much.
With the 96, were gonna cut out the cats, as long as it doesnt mess with our o2 sensors, it didnt seem to make a difference on the 92, but it only had one sensor.
It might be cheaper/easier to gut them rather than to cut them.
By the way, a stipulation for our class is we have to pull a plug wire on one cylinder to make it dead, ...
Interesting. Then on the 96, you ought to always pull the plug wire AND disconnected the fuel injector for the same cylinder together. That way you will be more economical and have zero fuel wash in the unfired cylinder.
Just remember to unplug/plug the spark wire and the inector wire together in pairs. I don't know if the PCM will balk if it sees one injector disconnected so what you could do is attach a dummy load to that injector plug (either an injector that's not sitting in the fuel rail, or a high power elec resistor with the right resistance in ohms). Either way you do this, you would make a wire extension on the extra injector/resistor so that the long wire extension can reach any of the 8 real fuel injectors. There is no performance gain in this, but it does make it cleaner.
and even when we pulled it on the side the single o2 sensor was on in the 92, I couldnt notice much of a difference.
The older ECMs never go into closed-loop operation with O2 sensor feedback while you are at WOT, or large angle throttle. There is very little info that the single O2 sensor provides at WOT other than the ECM making sure the mixture is always rich under certain conditions, and that's solely to avoid the engine from ever running lean enough to burn a hole in a piston. So in your case, it's not a surprise that you saw next to no difference because you don't drive on the track in steady-state speed and part throttle.
Even the laptop didnt pick up a rich condition.
It wouldn't because the narrowband O2 sensor used on the 91-93 and 94-96 doesn't have the ability to sense richness other than extremely rich. The sampling rate isn't fast enough and the narrowband O2 sensors are only accurate in the region of the voltage zero crossing. So if you were using the laptop (and WINALDL) to monitor the stock O2 sensor, especially for a racing application, you were probably wasting your time. You would need a wideband O2 sensor to make that exercise useful, and that's true for both the TBI car (your old one) and the new 96 9C1.
we pulled out the pushrods for that cyl on the first motor we ran because we thought it would throw off our fuel mix, but that just ruined that cylinder, so on the second motor we varied which cyl was dead from week to week.
That's a better practice, and on the 96 it's made even easier because you can disable the plug (via plug wire) AND the fuel injector (by disconnecting the connector atop the injector).
The gain in removing the pushrods would be preventing the cylinder from pumping air through it. I don't know why the cylinder was ruined because the intake valve should have been closed... so in theory no fuel should have ever gotten in there. OTOH residual fuel may have leaked it's way into that cylinder if the valve seat -to- intake seal wasn't great.
On the 96, you might still try the pushrod removal (even though it's more work) because you'll reduce the air pumpimg loss of the engine.
We will eventually cut out the mufflers too, I'm curious as to what it will sound like with just the resonators on.
Loud, but the resonators will help quiet things and losing the mufflers + cat innards will help a lot.
... We are not really able to change the cam, legally anyway. The rules are pretty basic, Don't do anything to the motor, but the techs let a lot of stuff slide, mainly eliminating things, but no aftermarket parts. I know a lot of guys do swap cams at our track, but racing takes a lot of $ that we dont have right now since we just bought the car, and time is running out to rebuild it. Maybe next year.
Is it legal to use an LT1 cam? i.e. an LT1 cam from a Camaro? It would give you more lift and duration. Cheap too (as the Fcar LT1 owners frequently do cam swaps).
You should keep the stock air cleaner for the 96 as it isolates the underhood heat from the air intake. Drill the lower air cleaner box on the front and side to allow more airflow. Use the stock paper filter so you can change it after each race. Consider using two if them if you can do the pumbing. The intake resonators can be kept because they really aren't flow restrictions, but the MAF screens are. Your engine can also be PCM setup for speed density mode so it won't use/need the MAF. You could leave the MAF in the car, but gut the screen and resistors, so it would look bone stock.
A 3.42 rear end (the center) from the 92 9C1 will fit into the 96, and the off the line response will be quicker... but on dirt you might not want the extra torque gain from it.
Make sure you do the proportioning and metering mods to the combination valve.