ok so i want to race my 1986 irocz 305 tpi i got rid of my air pump have exhaust fresh trans rebuild pretty good tires advanced timing to around 12* ill mostlikely run premium the 87 is bone stock 350 tpi timing is a bit off (spits out a bit of blu smoke) no exhaust both cars have ac who do u think?

 

forgot to mention tht i have a throttle body spacer from air raid

 

it depends on his rearend it mgiht be close thats like a buddy of mine has a 1991 gta with a l98 and i have 92 firebird 305 tbi with 202 hp to the tires and 268 tq to tires he has 193 hp and 272 tq but i have a 2.73 rearend he has a 3.23 posi he should get me off the line to about 30 mph maybe i got more thing done and i have a corvette servo he has a stock tranny both autos it will be a close race. but as far as you go if he has better rearend it goes down to power and tq who wins

 

I'm not sure on the rear could b the G92 option ill have to ask I'm pretty sure mine is the 2.73 I'd Prolly do 2nd gear to drive on the start I find tht there is less of a torque converter lag

 

i dont have that problem with my since i have a corvette servo your best bet is to start in first run the rpm up to about 4200 rpm then shift then 2nd then 3rd then 4th if yall go that fast i know i can do over 120 in 3rd gear

 

Tht would probably work better these pull hard in 1 and 2 and I hate the shift points on the 700r

 

mine shifts like a bad out of hell even with the 2.73 open rear i have everytime i hit 2nd gear i spin tires with it in 4th gear overdrive just from a red light and hold it to the floor your best bet is to get a corvette servo there like 30 bucks on summit it mad a world of difference for me and have your tv cable adjusted

 

Sounds like a good deal how's it shift from park? Mine hits pretty hard

 

it shifts fine from park the 1-2 and 2-3 shift is pretty hard

 

If the 350TPI is in decent running order (bit of blue smoke could just be valve stem seals) then you will get waxed.

86 LB9's are the most handicapped of the TPI cars.

 

tru tho i dont think hes ever raced any one so i got more experience either way it would be a interesting race

 

my bad its the 3.27 rear

 

The 86 TPI only had 190HP. They were detuned for some reason from the 85 model which had 215HP. He has a 30hp advantage, but there are so many variables that this may be close.

 

86 is the first year of the Peanut cam TPIs.

85 305TPI cars got the L69 cam, which aside from slight differences in later years is roughly the same duration as the L98 cams.

30hp and nearly 50lb/ft advantage in torque. Most L98's do about 200rwhp and 300rwtq on the low-end of the spectrum. With Mods those numbers go up. A member here has a spot on tune (not mail order) and he put down like 225hp and 315lb/ft I think to the wheels with a SLP 2otL catback and tune.

I've also seen plenty of dynos of stock cars doing about 205 or so to the wheels and 300-315rwtq. Yet to see an L98 dyno of a stock car with less than 300rwtq.

 

Yea I got the crappy cam but my timing is not stock I advanced it about 6* so if I'm not mistaken it souls give me some kind of hp gain correct me if I'm wrong

 

Only if it doesn't cause detonation. If it does then the ECM will pull timing and you'll be making LESS power because the ECM is trying to save your engine.

Base timing affects it everywhere. If the engine wanted 34* total timing, and you advanced base timing from 6* to 12* then total timing at full advance would go from 34 to 40*. And it might cause detonation issues where you WANT the power. If the ECM detects knock then its going to retard the timing.

 

Hmmm never thought of tht the whole story behind the timing idea was tht I had to detune the stock tuning so I would pass emissions then I took it straight back to the mechanic (GM certified) and had him tune it up as high as I could safely and still run unleaded regular supposedly the timing was advanced 6 so I should b good still runs a bit rich tho

 

Nothing is good until you have a dyno log showing no knock. The knock sensor is far better than the human ear at detecting knock. Most people don't even know what knock sounds like because the PCMs in cars retard the timing till there isn't any left.

If you really want proof, take it to the strip. With the car cool run 3 passes. Put the timing back to stock, and then let it cool off. Run 3 more passes.
If its faster than it was with the timing advanced then you probably have some knock retard.

If its faster with the timing advanced you are probably okay and not experiencing major detonation.

But the best way is to get the equipment and simply data log the car.

My car was detecting knock from my headers until I put the LT4 knock module in. I was seeing anywhere from 6-8* knock retard before the module. After the module I can see it occasionally on WOT runs, but its never consistent and its never more than a degree or two when it does happen.

The one time i had 87 octane in there i saw major retard at WOT. I only knew I had 87 because I looked at the receipt, I made a boo boo when filling the tank. For the next week I basically puttered around and never gave it throttle. I kept filling the tank back up with 93 every time I sucked about 1/4 tank down.

 

Thanks for the info I do hear a bit of clicking on wot idk if its the valves or there's a knock

 

Just talked to the mechanic I was way off he said its at 11.5 or so

 

Remember most of the "mods" you have done have almost zero to minimal gains besides a cleaner engine bay. Even if both cars have the same rear end the L98 will come on top.

Keep on reading I was in the same boat when I had my L03. Went from removing parts to replacing engines..

 

Just as an update I was unable to race him he wrecked his car a couple months ago

 

you would have gotten him anyway, no smog pump frees up sooo much more power!