I raced my 92 GTA on Friday and Saturday with the hope of hitting a high 13 second timeslip (bare minimum of a low 14 second slip). Much to my surprise, my car is now slower than when it was bone stock.

It ran a 14.62 @ 94.32 mph with a 2.211 60 ft on street tires (I did get a 2.158 60 ft once)

With ET Street Radials it ran a 14.43 @ 94.65 mph with a 2.045 60 ft

My best ever 60 ft was a 2.01 stock with ET Street Radials.

I added CAI, ASP crank pulley, and TPIS air foil and ran a 14.38 @ 94.63 mph with a 2.03 60 ft. The temperature was pretty hot outside so I felt the car ran pretty good for it being so warm. If it was cooler out, I think I could have easily run a 14.2 possibly even a 14.1.

A little while ago, I added a SuperRam intake manifold (with the stock intake runners and plenum), TB coolant bypass, Holley APFR, and 180* T-Stat. With this combo, the best I could do was a 14.91 @ 91.98 mph with a 2.167 60 ft on a prepped track. I was not happy about this at all.

The car has a smooth idle, and it feels like it runs pretty strong. After the SuperRam install, my car now shifts at 4600 rpm from 1-2, and 4900 from 2-3. Prior to the install it was 4900 for 1-2 and 2-3.

When the timing was set on the car it would bounce from 4-8* and it looks like it was set at the stock timing which is 6*.

The TPS at idle is .54 and WOT is 4.39. Fuel pressure was set at the stock setting which is 46 psi. I have put on the following new parts within the past 1500 miles:

AC Delco CR45TS plugs gapped at .035
GM plug wires
GM distributor cap
GM rotor
GM 02 sensor
GM EGR valve
GM fuel filter
GM PCV
GM IAC

A friend scanned my car and he noticed that is getting up to 5* of KR in first gear at WOT and none in second and third. I have always filled up with premium gas since I've owned the car and there are no trouble codes showing up.

I am not sure what is wrong and I would appreciate some input. Thanks for the help.

 

well for one i think .035 gap is suited for nitrous setups..not great for naturally aspiration..but i dont think thats the problem.

do you have any leaks with that superam? vacuum leaks, fuel leaks, coolant leaks?

also make sure your TV cable is adjusted right, it coudl be off now and causing your trans shifting problems

but the knock retard i'm not sure why your seeing that.

the bouncing timing kinda raises a flag, your timing shouldnt be moving that much. mine is set at 8 degrees timing and doesnt move around when checkin it with the light.

Check to see that the fuel pressure regulator is holding pressure and delivering the right pressure without a vacuum line connected. I have heard some holley regulators failing and causing poor performance.
Also feel that with your power, you shoud be trapping alot better than 94mph. most stock L98's are 95-96. with mods they hit 98 or so. with those drag radials i also feel you should be 60 footing better than 2.15+. I dont know the altitude where your at tho so that could explain a few things.

But this is besides the point, it shouldnt be running worse after superram install.

 

I don't have any fuel or coolant leaks. I am unsure about vacuum leaks. The TV cable is adjusted properly. I can check out the FPR on the weekend.

The track I race at is 1700 ft above sea level. If I was closer to sea level, I the car definitely would have trapped higher when it was stock.

 

I had an issue with my other car where the timing was bouncing around. It turned out I had two vacum leaks causing the problem.

 

Vacuum will not affect his timing. He does not have a vac. advance distrib.

If you have stock injectors, lower your fuel pressure to 42-43 PSI at idle with vac line disconnected. 46 PSI will make your motor run richer than it needs to which will kill some power.

You need PROM tuning to get the full benefit from your Super-Ram.

5* of KR is not too bad beings the factory PROM is capabale of pulling out 20*.

The best thing you can do is put it on a wide-band o2, collect a reading during a WOT pass and then have a chip tuned accordingly.

You may want to look at your plugs and the ESC module on your distrib.

Hope that helps.

 

Thanks for the ideas guys. Keep em coming.

My fuel pressure was 46 psi stock, it varies from year to year so I just set it at 46 psi. Just to clarify I didn't install the full SuperRam, just the intake manifold...I am only getting knock retard in first gear, not in second or third which is odd.

 

Ok, when you say you installed a SuperRam intake, to us that means the whole thing. Intake manifold, runners, and plenum. If you just installed an aftermarket intake manifold, then say only that.

Since you had the intake apart, there could be any number of things wrong. A vacuum leak in the gaskets, a vacuum line hooked up wrong or not connected, spark plug wires crossed, etc. Go back over everything visually and look for something out of place. Installing an aftermarket intake manifold will not require a custom chip. That's only needed for larger injectors or a larger camshaft.

 

I was under the impression that he had a full super-ram.

 

The exit ports in the Super Ram lower intake are larger than the intake ports on the stock heads. This step decrease in area really hurts flow. I wouldn't be surprised if the overall flow potential measured past this ledge was the same as or less than stock in the case where the Accel intake is installed without opening up the intake ports in the stock head.

My car ran no quicker when I swapped the stock base and runners for a Super Ram lower and AS&M runners. I think the mismatch listed above is the reason and could be the same for you. To find out if this is the case I've fully ported the stock lower base to accept the AS&M runners but kept the exit ports close to stock. I just need to find the time to swap intakes now.

 

I will spend some time this weekend trying to isolate the problem. I'm not sure if I'll be able to figure it out but I'll give it a shot. Thanks for the input guys.

 

You need to shift higher then 4600 RPM, the superram works well with 5200 to 5500 RPM shifts. If you want to shift at 4600 RPM the stock TPI tubes will work better.

 

I did some more checking on my 92 GTA a few days ago. I didn't find anymore vacuum leaks except for a PCV hose that had some cracks so I replaced it. I checked all of the plug wires to see if any were burnt - they all looked good. I pulled all the plugs - they all looked fine to me. The timing was checked with a different timing light and it was fluctuating between 6* and 9* approximately (EST was disconnected and the car was at normal operating temp). I also tested the fuel pressure and it showed 23 psi after the car had been turned off for 15 minutes.

I tested the vacuum as well and it was 14 psi at idle and 18 psi at 2000 rpm with the needle holding steady. I sprayed the intake manifold bolts and intake manifold gaskets with throttle body cleaner with the car running and it didn't speed up (I didn't get to the back two bolts on the passenger side though).

Anyone have anymore ideas of what to check?

 

5* retard at launch isn't bad. With my superram I had double that at launch and after the tranny shifted. Combination of too lean/too much timing.

For a short term fix, you could try backing down the inital timing 2* or bumping up the fuel pressure and scanning it to see if it goes away.

Make sure your knock sensor isn't tightened more than 14-15 inch/lbs of torque(not sure of exact number) and that your exhaust/headers aren't touching the frame in the engine compartment.

That vacuum at idle sounds really low, with a mild crane cam I was at 22" and with the LPE219 cam it was at 18".

The superram is a bear to seal, and it will take you a good 4-5 times taking it off and on to really get the hang of it. I had to assemble mine off the car to find spots that didn't seal well/weren't flat.

 

If your timing is bouncing up and down with the EST disconnected, I have to wonder if it might be something mechanical such as a faulty distributor or a sloppy timing chain. If your distributor is worn out, or the module isn't keeping the dwell steady, this could cause the fluctuation. Same goes with a worn timing chain. From what you posted, it looks like you're getting a steady vacuum signal, so that pretty much rules out a vacuum leak. On my TBI car, the timing bounces up and down quite a bit with the EST connected, but with it disconnected, it's steady as a rock. Since you recently replaced the cap and rotor, you might want to doublecheck to make sure the rotor is on good, and the cap is seated properly. A misaligned cap could possibly cause the bouncing as well.

 

i know whats wrong!!! no im kidding, but i have some suggestions, perhaps u might want to turn up the fuel pressure regulator, more pressure equals more atomzation. I think you ABSOLUTLY need to SHIM the distributor. mine was bouncing around from 6* BTDC to 13* BTDC and then back again, check my past posts. I had about .060" endplay/freeplay, i shimmed it to around .011" give or take .002". Also check for arcing at night, and test the coil if you shimm your dizzy, because if the coil isnt working properly then the spark is affected.. and if you do happen to soup it with a high 54,000 volt coil from hypertech or jegs, Then you can file down the the eltrode and gap to i think its.. .052" and the use of champion "cold" spark plugs, i THINK. adjust the tps. might even try after you adjust your TV cable, test drive it, if it shifts early, maybe tediously click it forward one click or back(cant remember which way) but it may help the shifting, if you havnt already put in a shift kit, which is easy. then a new filter a lube change for the tranny. you might want to consider a new coolant temperature sensor, and a MAT relocation is favorable, BUt i was checking out the 180* T-stat???you might want to get hypertech mod, turns fans on sooner.....for example, I placed a 180* t-stat in my ride two years ago, (perma dry gasket the best) and my car still hovers around 220*. yikes? I wanted to put 160* stat but then it wouldnt go into closed loop theoritically speaking, i would need a thermomaster prom then. i settled for 180*. so ya, input. im no specialist
--------------------------------------------------
What im editing...only the following are extended suggestion not related too much

If the car has more than 60,000 miles, and your racing it? eeeeeeee. i suggest you change the timing chain, True roller(not the autozone piece of 21 dollar and flimsy gasket.) get a crane cams, or at least 60 bucks, NEVER use a gear noise gear timing set, bad bad bad, constantly retards the timing due the knock sensor. If you got leaks, around you oil pan, then get a new gasket, invest in a PERMA dry one piece gasket (no sealants!) and while your dizy is out and your oil pan is dropped and replaced with a deep extra quart pan, check the oil pump, maybe a high volume swap? and replace the motor mounts and tranny mount, and torque arm bushing if you replace the tranny, (its right there) a shinny balancer, new water pump, coolant hoses under neith the car.. etc etc etc