Ok, heres the deal, me and my friend went to the track last friday night with our Camaro's and did some runs, he bought his 91 RS 305 TBI about 2 months ago, and since then i have helped him install a 94 LT1 cam, edelbrock torker II intake, March 3 piece pulleys, flowmaster 2 1/2 exhaust, holley 670 350 TBI unit, 160 degree stat, and 14 x 3 open element KN. He basically has about the same engine mods as i do in my 350 TBI RS, but stock my car ran a 15.6, his ran a 16.3, now last friday night, i ran a 15.27, and the best he could run was a 16.047. Shouldnt both of our cars been much faster with our mods ? But especially his. He was really disapointed, i was too, but my car wasnt tuned quite right so i think thats where i lost my time. He said his car seemed to run great. Our time slips are posted below if that might help, but im lost, because to be honest, i drove his car and it seems to run good, no hesitation or anything, so i figured i would ask the "experts" here for a lil help on this problem. Thanks guys, hope u can help us both out.

Timeslips - his -
temp - 84
humid - 77
light - .709
60 ft - 2.411
1/8 - 10.990 @ 69 mph
1/4 - 16.047 @ 86 mph

mine
temp - 85
humid - 82
light - .506
60 ft - 2.398
1/8 - 9.983 @ 74mph
1/4 - 15.27 @ 93mph

 

oh, i forgot to ad, he also has the 3.23 gears, i gave him my old ones out of my v-6 rear end, thanks

 

exhaust and tuning

 

Traction???
Those 60's are really hurting you guys. Do you both have posi's. LCA Relocation brackets will help alot. Or consider drag radials or slicks. Also, you should expect to run a little faster with the humidity being much lower. Hope this helps.

 

Definitely needs some tuning. Messing with the FP, and custom proms.
We can't give you a cookie-cutter solution, because all cars are different. It will take 2 things to tune these cars:
1) A new prom,
2) and Joby's WinALDL to monitor the engine.

 

i was at the track the other day and ran a 15.97 with a 2.24 60' ( had no traction problems) with the mods in my sig. I have just done the Ultimate TBI mods, the TC lookup switch, and hopefully with some fuel pressure tuning and a timing advance (ordering a summit fuel pressure gauge this week) i can get at least 2-3 tenths before i have my 3.73 gears and SLP take off posi installed.

 

If I had to guess I'd say your buddy have a weaker fuel pump than you do. Otherwise....

3rd gen Fcars, w/350 and Fcar LT1 cam..... hummm, 4th gen Fcars with LT1 run in the 13s, so you both should be running high 13s at the very least.

I saw all the mods, which really should make you close to equal with a stock 4th gen LT1 Fcar --- except you never mentioned fuel tweaks (pressure), nor modding the ECM. And modding the ECM is almost entirely aimed at computer-controlled fuel delivery tweaks. I could have said "tuning" as others have, but I wanted to be more specific.

You appear to have done nothing to increase the fuel delivery on a speed-density computer controlled car. So THAT's the big problem.

You aren't running quick/fast enough to warrant big suspension changes (yet), the problem is you are not supplying enough fuel. Don't waste your time messing with the suspension. And yes, improving the launch to 60' will help, but not enough IMO... the launch isn't really the problem and that'll get fixed with more seat time.

You need to read the old posts on this forum concerning what to do. Hints: simply raising the fuel pressure will help a little but it won't solve the problem. Using the vFPR (or vaFPR) should help more because you'll be making load-dependent increases in fuel pressure, but that won't fully solve the problem but it's better than just a straight increase in FP. Doing the vFPR and custom ECM is the only way of finally getting it right and optimized.

If this post sounds like old stuff -- it is. Many people before me have said the same thing about modding speed-density vehicles, and they're probably tired of answering the same question again. Maybe there should be a permanent sticky topic on the need for more fuel in modified speed-density vehicles, that's closed, and written by the moderator.... because this issue comes back over-and-over again.

Do a 3rd Gen TBI search using the above fuel-related items, makes some changes, and post back on the results. HTH, IMO, FYI. - Ken

 

both myself and my friend have the holley 670 tb, so we have played with the fuel pressure on those some, im not positive about his, but my car will really only run well at one certain pressure on the tb, if i move it up higher, or lower, the car will either have very slow throttle response, and miss a lil, or it will miss and stutter like crazy at a higher fuel pressure. I have alos played with timing some, but that seams to be a very fine line as well. If i move it too much one way or the other the car will not perform even moderately. I figured a new chip would have to be in the making, but im not sure really how to go about doing that, other than calling up hypertech, or ed wright and getting one made through them, however, i have heard that those chips arent worth the money, and wont give me the peak performance that a real custom chip would. So if anyone knows anyone who could burn me a chip, or where i could get one done, please feel free to help me out, thanks guys

 

Timeslips - his -
temp - 84
humid - 77
light - .709
60 ft - 2.411
1/8 - 10.990 @ 69 mph
1/4 - 16.047 @ 86 mph

mine
temp - 85
humid - 82
light - .506
60 ft - 2.398
1/8 - 9.983 @ 74mph
1/4 - 15.27 @ 93mph [/B][/QUOTE]

Your reaction time is excellent! (your buddy's a little slow)
Your trap speed of 93 MPH sounds more like a 14.5-14.9, so I'd first say that traction is a problem.

You both have mods that SHOULD work and work well together, but you didn't mention the front of your exhaust system. Do you still have the very choking, itty-bitty Y-pipe before your more open cat-back exhaust system?

 

Dude the the only similarity to an LTI is the cam , without the intake , cylinder heads and everything else it wont equal the LT1.

 

Something is definately wrong. I don't know if the Holley 670 is too much for the engine, or the cam was installed advanced/retarted...it isn't JUST chip related.

With a 305 and the mods in my sig, using the OEM TB I'm running in the 14.7's. Someone said the headers/Y-pipe...if that isn't gone already I would imagine with the new cam/intake/open element the engine can't use the better intake and exhaust b/c it can't breathe through the manifold/T-pipe.

Your 350 should also be running much faster...like a second at least faster. Where are you racing at? Is the elevation really high?

Sorry I couldn't be more help...I'd start hooking gauges to it until some flag goes up.

 

93-97 Fcars with LT1 had 275 or 285 (depending on the model year) fwhp stock. His (jc92camaro) mods should at least equal 275-285 fwhp. And the people that referred to 305s running in the 14s is another datum that the 350 should be running at least in the high 13s.... which is what I said.

Yes, the LT1 (or in his case) the L31 heads would work better, but it's not that hard to get 275-285 fwhp from a LO5/L98-type 350. FYI.

 

Haha its alot harder to get 275 from a l05 than it is from a l98 or an LT1 , and the induction system has something to do with it. You cant slap a cam in something with an inferior induction system (yes TBI is inferior to LT1) and expect it to put out the same power. Judging by his MPH his car should be in the 14.6 -14.9 range but it still isnt putting enough power to the ground to be in LT1 range. FYI

 

wow somethings up with that car. I dont really even have that much mods and my car goes 14.9@94mph with a 2.419 60'. Thats also with not punching it hard enough off the line. I was afraid of losing traction and babied the gas to much. Stupid me. Then my starter felt it wanted to overheat so it didnt wanna start and I couldnt race for the rest of hte night

That car looks like it needs a fatter exhaust and some headers. strange though...when my car had less mods it ran 14.9@93

OLD MOD LIST
K&N 14x3 open element, Hypertech underdrive pulleys, FLowtech shortie headers (they sucked), 2-1/4" piping (that really sucked), flowmaster muffler, 3.27 gears w/posi, L98 Cam, ported throttle body, raised timing, and bald rear tires.

Very strange...

 

yeah there's a problem somewhere I ran a 15.043 with a 350 with lo3 heads 305 injectors , 3" exhaust, no cat ,cam unknown was told it was a "towing cam" with some good wheel spin that time 60' 2.4 first run now spinning and got a 60' 2.02 but ran 15.073 in drive

 

You put a Holley 670 350 TBI on a 305 engine... that's already bad... Need to drop the fuel pressure on that thing... they made the Holley 670 TBI 305 for a reason you know...

Next tuning.. can't stress how much tuning will help, especially after a cam swap.. odds are you are hurting in that department.

Those 60ft times hurt... too much spinning no gripping...

 

I'll save my opinions, but I ran a 14.96@93.07 a couple weeks ago in similar weather with the engine at 220 degrees in a for sure heavier car than yours, close to the same 60' time. I think I had a 2.35 or maybe 2.29, dont remember offhand. Anyway, you're at least .3 off IMO.

Oh, its a 350 TPI FYI. The 305, if the heads are stock then I am not surprised he didnt run well, those heads suck. Bad match to that manifold.