wariat87

Greetings all,

I was having a heated discussion with a friend of mine about this. He has a bone stock 97 z28 with LT1 (engine is a little tired). The only mod to the car is the rear end (4.11 I think).

I told him that I'll run him next spring with that setup. My car is an 87 IROC with 305 TPI. The car is mostly stock... except for flowmaster catback and airfoil... but I tell him that I plan to put in high flow cat and bigger cam.... as well as 100 hp shot of laughing gas.

Needless to say... he still believes that he can take me with that setup. I disagree. Any other opinions?

thanks,
Wariat

Nitrous Al

If you ran the cars now, I think it would be very close. Once you do the high-flow cat, the cam swap and nitrous, you'll rape him. Wariat, run him now, heads up, no BS, for sheets & giggles and post the results!

ShiftyCapone

iTrader: (7)

We will assume his car is running the way it should.

If you run him now he will murder you. With a full exhaust he will still murder you. With a cam you will hang better (asuming you do the chip work) but he will still beat you. With a 100shot you should win that one.

When I had my stock '95Z I never lost to a cammed 305 of any kind.

Driving skills and vehicle condition could put any race in your favor though.

urbanhunter44

iTrader: (3)

I agree with shifty here. You're going to need H/C/I to beat him N/A. On the juice, with the cam and exhaust, you should have it.

Ray87Z

I just posted the results of my old modded 305 TPI IROC (now my younger brother's) vs my new bone dead stock 94 Z28 A4 a week or so ago.

The 305 has a mild cam (204/214 dur, lift of .420/.442) , ported plenum/matched runners, homemade cold air setup w/ K&Ns and a airfoil, TES headers/hi-flow cat/flowmaster catback, rebuilt tranny w/ 2200ish stall converter w/ 3.42s out back.

My 94 Z28, again absolutely bone dead stock at the time down to a paper airfilter whipped it pretty decently, had a full 2-3 cars or so on the 305 and was still pulling in a little under a quarter mile run.

I'm assuming your buddy has a 6speed with the 4.1x gears out back, and the 97 should have a rated 10 extra horses over my 94. Those gears with the 6spd cars are supposed to be pretty nice and would probably be noticeably faster than my 94 A4. He SHOULD be able to get into the high 13s driven/running well, 14.0ish at worst. Off the spray I'd say your dogmeat by at least a second in the quarter, and since you don't have alot of the regular bolt-ons on your car yet and I'm assuming 2.73s, I think you may still lose on the spray even with a mild cam. That's assuming the LT1 is running decently though... Who knows, the spray may allow you to eek him out, it should knock right around a second off your quarter time so...

I think you would almost for sure win if you had all the supporting mods of headers, ported plenum and maybe some aftermarket runners, along with some good gears to go along w/ the cam and spray... Without them, ehhh.......

87TPI350KID

Just put a 200 jet in and win. Nuff said

wariat87

wonderful feedback... gives me some ideas... the majority from my circle agree that I would probably take him... but I think the proof is in the whooping!

BTW, he's running an auto not 6spd. I think he can shift it pretty good. he is claiming 13.8 time slips.

Either way, I think it would be close. I'll be doing a little port work on the Heads and intake (runners plenum) in addition to the cam swap and haha stuff. I don't know about the rear... but I'm not sure if I'm running the current 2.73 in there but will definitely check that. Anywho, got big plans for this machine... about three years will start a motor build up that will come in all aluminum 7.0 liter flavor and I may throw a huffer on it just for good measure. Till then, however, I'm gonna have myself some fun and maybe shutdown a few unsuspecting weekend warriors.

Thanks again guys,
Wariat

mickman

The only way you'll take him is with nitrous. If not you'll lose. I had a sound 305 tpi in my car before we put the 93 LT1 in it. There is absolutely no comparison between the two, to even try to mention them in the same sentence is just silly! Regardless of ANY of your mods, you will lose. Unless you have the NOS on tap, then you've got a shot but still doesn't mean you'll win. I think you will with nitrous but if not your 305 will be exposed for what it is, a 305! The LT1 pulls waaaay harder than your 305 and with those gears you could be in trouble. I'm not trying to hack on your setup, it use to be mine. But if you asked me my car before VS. after engine swap the tpi would need binoculars to see my tail lights. Good luck!

fly89gta

iTrader: (1)

Riiiiiiiiiiiiiiiiiiiiiiiiiiiiiiight

Mcdamit

Your car= Meat..... you run mid 15's
You would have to drop at least 2000 to even think of racing him. To race him N/A you would need a cam, gears, heads with heavy springs and self aligning roller rockers, intake, injectors, a chip, rebuilt dizzy, timing advance to about 15* @ base, 93 fuel, and some nittos.

Here.... First off, Camshaft the peanut wont fly look into lunati's voodoo line the 268 cam might do you well, some nice vortec heads would help as well, get them out of the junkyard and save $$. Long tube Headers, custom dual exhaust look it up, 3.45 or 3.42 posi gears with rear discs. You can find them but it will cost you. TPIS baseplate, AS&M Runners, ported plenum, and a rebuilt t-5 with a centerforce clutch and some sticky tires. Then an aluminum driveshaft . Well go buy a fourth gen @ that rate.

urbanhunter44

iTrader: (3)

13.8 is correct with his only mods being 4.11's, through an auto. I actually slightly surprised they aren't lower, around 13.6-.7. Probably ran a 14.1 or so bone stock.

mickman

A LT1 has a whole lot of torque and those gears only multiply it. Instead of trying to build a 305 just do what I did and drop a Lt1 in your car, or better yet a LS1, than you'll be in business. I don't want to rip on you but need to tell you from my personal experience that we're dealing with two different animals here! Its like having Rolls-Royce dreams with a tricycle pocket book!!!

cas0484

I'm gonna have to agree with everyone here and say you won't have a chance unless you do h/c/nitrous. If he does lose, it will probably because he will have a hard time hooking with those 4.11's through the auto. I've always been told not to go higher than 3.73 in those cars or else traction will be a huge problem. If he's running street tires, he's gonna roast them like crazy. Goodluck though!

urbanhunter44

iTrader: (3)

I wouldn't go 4.11s with an auto just because of the RPMs, unless it was a track only car. The highest I'd ever go in an auto is 3.73s, with a nice 3500 stall converter.

4.11s are okay for M6 cars though.

The rear ends tend not to like it however......

phoenix305

actually i did the caculations and with 4.11's and AOD you would be crusing at around 2300 rpm @ 65 mph with 16 inch rims and a 235 55r-16's. so not that bad.

cas0484

Yeah, the rpm's aren't too bad. Its the traction that becomes a huge problem. I've seen plenty of guys run 4.xx gears through their auto Lt1 and it's kinda self-defeating, unless they are running a matching stall and a good set of tires, they'll do nothing but spin. My friend's full bolt on 95Z orignally had 4.11's and he had the hardest time hooking on a good set of tires, I can only imgaine with an auto.

mickman

It shouldn't be all that hard. I mean, BFG's cand hold like 8 second cars they can hold my Lt1 with 4:10 gears. I'm getting a set over the off season and can't wait to see how hard my car will pull then. Having said that, I have NO traction on my street tires.

wariat87

well it seems that the scales have tipped back in the 4th gen's favor. I have to disagree about the above mentioned time slips. I can bring the car into the high 14's in current trim.

As for the second point. I'm not wasting my time with a LT*. The next engine going in the car will be a one off design that will be aluminum block and heads and forced induction. I doing some research right now but I have had a simulator rate the motor at about 738 hp at 6400 rmp (on pump gas). It currently displaces 405 cubes... but still working on that.. may decide to base it on the 7.0 liter z06 motor that's coming out.

I just wanted to throw a few bolt ons into the current setup to get some idea of what i can pull. I'm not too worried about the race. He seems pretty confident and I think his ego might be his worst enemy. I'm still not sure of the current gears in the car, can someone give me a suggestion as to how i can find out without actually taking the cover off the rear and counting teeth?
If the gears really are 2.73 then that is definitely a quickie mod i might do.

My final tally on the current drive train will include these mods: Heads, intake, plenum, runner port work; higher lift cam(not sure of the grind yet, any suggestions? not too wild please); bigger cat and headers; Nos kit for TPIs; some chip work; some sticky tires. All else will remain the same until the new motor will begin construction.... then the car will be literally rebuilt from the street up.

talk with you guys soon,
Wariat

mickman

Just go to your local GM dealer service center and have them type in your VIN number and all the info will be in the computer! Thats how I found out that my 305 TPI was equipped (if you can call it that) with 2:73 gears. If your getting really GOOD gas mileage I'd suspect thats what they are. A quik gear swap is an easy thing to do! It will wake it up nicely!!!

ShiftyCapone

iTrader: (7)

RPO codes and build sheets only tell you what the car came with stock. Gear swaps are very common with these cars and the only way to tell is to pull the cover. You are nine or ten bolts away from your answer. If you can't remember the last time the rear fluid was changed than it needs to be changed anyways.

phoenix305

everyone thinks that a nine or ten bolt refere's to the number of bolts on the differential cover, this however is not true, its the number of bolts holding the ring gear to the carrier. But in the gm nine bolt and ten bolt they do have nine and ten bolts on the cover. Just a coincidence.

ShiftyCapone

iTrader: (7)

Where did you hear this? I am pretty sure a 12 bolt doesn't have 12 ring gear bolts.

urbanhunter44

iTrader: (3)

I've never heard that.. I've always been told 9, 10, 12 bolt etc., refer to the number of bolts on the cover. Whoever told you that was mistaken.

DuronClocker

iTrader: (1)

He rightfully has an ego because he knows its going to take a lot of work for you to be able to beat an LT1 wiht 4.11s, even if he is an auto. If that trans has any work done to it (higher stall torque converter, shift kit, etc.), he'll be even quicker.

You better get your car custom tuned if you're going with new heads, a bigger cam, and an opened up intake. Your stock transmission and 2.73s are going to be your worst enemies. I'd say get at least a 2200RPM stall torque converter. A 2500RPM would be even better. Then get something to help that trans shift firmer and last longer. Then get some better gears, like 3.23s or 3.42s.

I ran SLOWER with my mildly worked LT1 heads, LT1 intake, and CC304 (210*/220* .500"/.510"). Then again, my car wasn't tuned at all and was running a stock corvette tune because I didn't have any time before the track date. Needed a TON of tuning, and all of my power was over 3000rpm. Didn't like the lower RPMs much, but it seemed to scream over 3500RPM, even without a tune at all. Ended up spinning a bearing in the process of a 15.2 run. I was okay with the time though considering I had just got the car running and knew it needed a lot of work. Have a feeling the spun bearing didn't help matters much.

Just be careful when you do heads/cam/intake work on a stock bottom end, because it will love to rev, but that stock bottom end won't

DuronClocker

iTrader: (1)

Before that swap, I ran a few 14.7s @ 93mph with 2.3x 60's and 14.5s @ 97mph with 2.4x 60's on a fat 60shot of spray.

Stock peanut cam, stock heads, 1.6 roller rockers (that weren't adjusted 100% at the time), SLP 1 3/4" headers, hi-flow 3" cat, 3" SLP 2otl exhaust, K&N CAI (though I think its there more for sound than performance), stock TPI induction, recent tuneup with MSD wires. 3.23 gears.

If I had traction that night, I would've been running damn close to 14 flats or better. So heads, cam, exhaust, and nitrous should net you 13s.

My above post was more or less saying you don't have a chance in stock form.

EDIT: Changed the above times, I was .2 sec high on each one.

wariat87

thanks for that post... gives me some ideas... both my friend and I agree that I wouldn't stand a chance in current trim. I do have many plans in the works for the current drive train... I was gonna swap rear end gears but wasn't sure about the converter (now I am definitely considering). The goal is for me to be able spank his stocker LT1 *** with a 305 motor. Once I am satisfied the 305 will be pulled and sold and a very new, very light (all aluminum), forced induction, 7.0 liter power plant will find its home under the hood of my little IROC.

thanks for the continued info on this,
Wariat

83 Crossfire TA

iTrader: (2)

there are 12 bolts with 10 bolt covers, but the 9 bolts refer to the 9 bolt covers.

As far as who’s going to win… 13.8 is pretty slow for that combination… my ’97 WS6 (yea, a few extra hp but I’d bet that race weight is a couple of hundred lbs over most), with a 6 speed + just 4.10 gears has run 13.0@107.

A friend of mine got a 87 formula, 305/5speed to run 13.7@101 with a home made intake, edelbrock headers, stock cat and a dynomax cat back. With some careful tuning a 305/auto/3.23 gears should be in the same ballpark with headers, exhaust and intake, of course, all this depends on what your driving is like.

If you have 2.73’s, well, ditch them, but if you have the choice of a converter or gears I’d choose a converter over the gears, a good (like PI, yank…) converter with a 2800-3200 stall speed will more then cover up some too shallow gears. Of course, if you go with a cheaper converter I wouldn’t recommend that high a stall. Also, unless you’re a good driver more converter will probably result in more wheelspin unless you go with some sticky tires.

Inwo

I see one MAJOR issue with your cunning plan.

Don't spend too much money trying if you intend on selling. Otherwise, grab a big shot of nitrous and a prayer and good luck.