87TPI350KID

This week we had a local Fbody gathering. Some nice cars came out as well as a bunch of my friends. One of them got a new Lt1 car, beautiful. It has an Auto, 2.7x gears, LT1 and 76k miles. I was curious to see how I could match up so we ran it on the highway to about 80 mph. It was from a 10 mph roll or so and we gunned it, my gears and torque helped me pull a quick 3 car lengths, then his lt1 started reving pretty high and caught me at about 40 mph, then i started to pull ahead a little bit and put a fender on them where he stayed till about 80.

He would have DEFF had me if he had some better gears. Not bad considering it was an LT1, all stock though.

ShiftyCapone

iTrader: (7)

Good run. His car was plagued with the A4 and lame gears. Those two items alone can put an LT1 car on par with an L98.

IROCThe5.7L

My buddies 95 Z28 Convertable with the highway gears ran a 14.2 bone stock.

cas0484

Nice kill. Lt1's with 2.73's are dogs. Woulda been different with some 3.23's or 3.42's. Good kill though!

87TPI350KID

It was certainly a good race. With his power band and gears, he pulled on me like a mother up top. From a dig, TPI still owns the road. On the highway, LS1, but LT1s still hold thier own.

phoenix305

i was unaware that a car that runs 14.3 stock was considered a dog.

89IrocZ350TPI

14.3 is pretty quick in my book

Street Lethal

iTrader: (16)

On the street, 14.3's is honestly pretty quick. But on the track, after running some 11 & 12 second passes... it's like watching'em race in slow motion.

urbanhunter44

iTrader: (3)

From a stop the 2.73 gears aren't very helpful but they are nice for commuting lol

A set of 4.10s helps alot in an LT1 car, ask me how I know

But it sounds to me like his car needs a serious tune up. From a 10 MPH roll his car should have been in first gear at WOT and with the highway gears he should have had no traction issues. And with the auto it should have shifted perfectly. That was actually an ideal situation for a stock LT1, im extremely surprised that you pulled that hard on him, as I know for a fact that a catback only A4 3.23 '94 LT1 (fully loaded at full weight) with 145k will pull a ZZ4 cammed/full exhaust/chipped L98 IROC with 1500 miles on the engine through the whole powerband.

I'd tell your buddy to do a complete tune-up. And he might want to think about replacing the optispark. He's probably got another 25k on that one, but it's pretty old if it's the original.

And I wouldn't quite say LS1s own the highway.. but if you were talking stock vs. stock then yes LS1s are decent motors. However the SBC 350, the LT1, the LS1, and even the LS7 block all have pretty much the exact same potential, with the SBC 350 and the LT1 having ever so slightly MORE in virgin bore/stroke form. Pet peeve of mine.

89IrocZ350TPI

My car has 3.42's when it had 2.77's it wasnt that much slower. Maybe the 2.77's on the TPI cars work better than they do on the LT1's....

87TPI350KID

Well his car was owned by an old lady (go figure ) and has NO mods, even a paper filter. I will suggest telling him to get a tuneup, he's still learning the LT1 style motors since he left TPI. Once he gets it running good he gonna buy some 4.10s, LTs, and an LT4 conversion package

cas0484

Everything sounds good except for the Lt4 package....tell him to stay away from that. Look into Lloyd Elliot H/C packages. More bang for the buck. LE1 packages put you around 370-390rwhp for 1100

urbanhunter44

iTrader: (3)

Yep, tell him to stay the hell away from the LT4 package. it's a WAY overpriced pile of sh*t. Basically.

His first mods should be a catback, headers, 3.73s/4.10s (4.10s are a bit much for a daily driver, although I do it and I'm fine with it), and a 3200ish stall converter. Along with some good drag radials. Those mods will easily put him at mid 12s.

As for heads/cam, as said above, Lloyd Elliot is without a doubt the BEST choice for the LT1. For a little over a grand you can have 380 RWHP using stock casting ported heads and a mild cam that passes emissions and is daily drivable. www.eportworks.com

First off, 9-bolt cars had 2.77s, 10 bolt cars had 2.73s.

They are essentially the same gear, the difference in the two cars is the powerband. A tpi car can seem fast still because it's not revving out of it's powerband as quickly with the numerically lower gear. A TPI car can very easily be over-geared, I.E. I believe a set of 4.10s would be WAY more gear than you would want to ever get near an L98. An LT1 cannot as it pulls very easily to it's redline. That's why the 4.10s in my car did nothing but make it much, much faster.

89IrocZ350TPI

So for L98 cars are 2.77's decent gears for the powerband? Why else would GM use them in a performance car I wonder. I remember the 2.77's pulled really strong threw the gears.... I hear 3.23's,3.27's are great gears for L98s. Nothing over 3.42's is what I was told.

Street Lethal

iTrader: (16)

Not at all....

Think of it from a sales perspective... it's all a balancing act for GM. The LB9 had to keep up with the F-Body L98, but couldn't surpass it (for obvious reasons, otherwise the L98 purchaser would be complaining)....

Think of it this way, if GM decided to produce the Iroc and GTA with L98 power, five speed, posi rear (w/3.45 cogs), there would be no reason to even look at the Corvette....

... a balancing act.

I'll have to diagree with whoever is telling you this, as TPI makes its power down low, under 4500-RPM, so the lower the gear (higher, numerically), the better (racing wise)....

urbanhunter44

iTrader: (3)

And I'll disagree with that. It seems to me that L98s would benefit most from 3.4xs if they're an otherwise stock street car, keeping the rpms low and not making them rev like hell. I could see 3.73s in a street/strip car with all the bolt ons to the TPI unit.

I've ridden in a 4.10 equipped L98. The owner of the GTA swapped in a 4th gen rear that already had the gears - his previous gears were 3.27s. The car was slower than before the swap - strip proven. He lost .2-.3 tenths and 1-2 MPH. It would get off the line really fast, then just slowed down as the revs climbed.

Have you ever ridden in a 2.7x/3.0x/3.2x equipped car, and then changed the gears to 4.1x cogs? It winds up MUCH MUCH faster. Plus when you're already at a roll, the rpms are much much higher, which is bad for TPI.

If I had a street L98 I'd put 3.4x gears in it for sure. Of course I wouldn't even bother with gears before I swapped the TPI for an HSR, but that is hypothetical.

Street Lethal

iTrader: (16)

"Keeping RPM's low"? It's apparent that you are relying on the L98's torque to win you're arguement. The sad truth is, even with 3.4x gearing, you're still in the 14's with an otherwise stock L98....

Reiterating on the "balancing act" concept, I'll bet you any amount of money (friendly, so don't take it the wrong way), that I'll run a lower ET, naturally aspirated, in an otherwise stock L98 with 4.10's, than you can with 3.42's....

Of course, the stock 700-R4's internal gearing will hinder the potential a 4.10 cog can provide down low, but this is nothing a TCI "Saturday Night Special" converter, and lower set of transmission gearing can't fix (mainly first and second)....

If I implied that 4.10's will do wonders on a relatively "stock" L98, then I apologize, as my point was to balance it out, of course.

Well, this also has much to do with the driver.

urbanhunter44

iTrader: (3)

My keeping rpms low comment had to do with the fact I was speaking about a street car and keeping the rpms down on the highway is a plus for a daily driver.

Maybe you would, however I'll bet that I'd run better with 3.73s than you would with 4.10s, based on my personal experience with L98 cars. I even said this above, in a strip car I'd put 3.73s, not 3.4xs.

No one was even talking about changing gearing in the transmission. I bet less than 1% of TGOs members have gone that far.

Also, imo, TCI converters are for people who want to cheap out on their build. If you want a real converter, go with a Vig or a Yank. But again, that's just my opinion.

And my friend with the GTA, his 60 ft/330 ft times were very comparable between each run and his et/mph was very consistant, only varying with temperature. He is an excellent driver. The tranny was a 700R4 with stock gearing but built up a little, and he was on DRs (nitto 555rs I believe). He has since changed to 3.73s.

Street Lethal

iTrader: (16)

Come on now, 4.10's being backed by an automatic overdrive, isn't that bad. I myself run 4.10's in my 86, and even before my gear swap (tranny), it was fine out on the highway.

Let's also remember that the stock TPI is an absolute dog at higher RPM's, so the only real benefit out on the highway is gas mileage. Which if this is the case, fine, 3.42's win over 4.10's.

Same here....

.... and still, the majority of them 'wonder' why there car's can't seem to hit 12's.

.... and still, the majority of them seem to 'give up' after a few months, than go the Mustang/Import route.

Well, I only mentioned the "Saturday Night Special", because it's stall is right around a "stock" L98's peak. If a Vig, or a Yank is right up you're alley, I'm all for it....

I was not insulting you're friend, it's just you can't swap to a taller set of gears, and expect to immediately drop a full second. Much like a cam swap, things need to be modified to compliment it. Much like a cam swap, YOU'LL RUN SLOWER IF YOU DON"T BUILD AROUND IT.

ShiftyCapone

iTrader: (7)

You want to pick a gear that will keep your engine operating over the longest part of its powerband. Going with a numerically higher gear can slow you down if your motor has a narrow powerband. A TPI motor has a narrow powerband and you want to pick a gear that will allow you to accelerate through that narrow band. A higher gear will reduce the amount of time you spend in each gear thus keeping you out of the of the usable powerband. Going bigger does not necessarily mean you are better off.

Street Lethal

iTrader: (16)

... so you're saying a 2.77 through 3.42 gear will benefit an engine that makes it's peak power between 2500-4500 RPM, better than a 4.10 gear can? Exactly how long do you want each individual gear to last (through that particular RPM)?

Funny how most of the guys running Pontiac engine's (low RPM, torque motors) at the track elect to run with 4.56's. I guess they haven't heard about the potential of those 3.42's yet....

Much emphasis was already placed on the fact that 4.10's will not drop you're "stock" L98's ET by one second. Yes, the TPI has a narrow powerband. But so what? Who here is is honestly building around the stock L98's cam, and TPI system?

... and even if they were, port out the stock TPI's intake, plenum, throttle body, and throw in a much more aggresive cam, and the 4.10 shines over the 3.42. Which is pretty much what my point was all along.

Usable powerband? Since when were stock L98's even considered "powerful"? I think you're making a mountain out of a mole-hill, as 4.10's aren't that much of a real difference from 3.55's, and/or 3.73's....

Don't take this the wrong way, but are you yourself running in the tens yet? If not, most of these words are completely fluff. It seems that almost every guy that I meet (not you), while waiting in the lanes at the track, talk tech like it's second nature, then they leave from the tree... and throw down a whopping thirteen second pass.

I can go to the track this Wednesday night, reiterate everything that I just read here, and this still won't change the fact that in 1/4 mile racing, the guys who are running sub-eleven timelsips, are the guys running much taller gears (naturally aspirated, of course)....

Nate86

I think you missed the point that we're talking about a stock L98 here.

I highly doubt any of those sub-eleven timeslip racers are using TPI as their choice of induction, either.

ShiftyCapone

iTrader: (7)

This is my point exactly. Those same 11 second racers make power from 2k to 6.5k thus making the most of a tall gear. It doesn't matter how much peak power we are taking about here but instead over what range. The actual value of power for this debate is negligable. I am not rying to say a 2.XX gear is better than a 4.XX gear. That is not the point I am trying to make. The point is to match a gear that correlates to your engines powerband. Bigger doesn't always mean better E/T's. Matching a gear to your engine does.

Guys who run elevens most likely have a motor that makes flat power over a 4k rpm range between 2500 and 6500. Since the motor makes power at such high range, using a numerically high gear gives them the most mechanical advantage while maintaining increased acceleration. This theory applies to any engine no matter what power it makes. A stock L98 has roughly a 3k power range from 1500 to 4500rpm. You therefore want a gear that is going to give you the most mechanical advantage and acceleration. A gear that is too tall will not give you this. You will have tons of mechanical advantage at the cost of decreased acceleration. You will waste usable powerband. You want to select a gear that gives you both. The gear you choose isn't some NASCAR gear by default.

87TPI350KID

All I know is if you run 4.10's with TPI, you better have mad crazy 60 ft times.

I love my 3.27's, they wind up real nicely. Bangs into 2nd around 45 and 3rd at about 74. Havent hit the OD shift yet at full throttle. I've rode in a TPI car with 4.10, unless all of your races are 0-40, forget it.

Blu91Z28

If you want to see how great 3.73-4.10 gears are for a stock TPI, try running the combo thru Desktop Drag or something similar. This about sums it up . Beyond the fact that you'll never hook up on the factory 245/50/16's, you'll also run out of powerband. Ideally, aren't you supposed to cross the finish line at peak power? Keep in mind that built TPI Vettes, I'm talking heads, cam, ported plenum, ported base, big runners and TB are running low 12's with 3.08 gears. The TPI intake design simply will not flow enough air above 4,500 RPM to satisfy a 10 second N/A car.

IROCZZ3

One Vette guy swapped from 3.08s to 3.42s and did not gain anything. Keep in mind it's a Superramed 383 that already ran mid to high 11s at 116-117 mph, IIRC.

87TPI350KID

All 4.10s are good at doing is drinking gas.

urbanhunter44

iTrader: (3)

Maybe for an L98, but in my LT1 I retained decent gas mileage with my 4.10s, and they compliment my powerband extremely nicely.

Yeah I think street lethal missed the point that we were talking about bolt-on L98 cars here. Most people on TGO will never open their motor.

3.492rs

hey my car didn't have full exhaust/tuned chip and it had 2.77 gears and it only had 650 miles on the motor when we raced,it blew up at 1200miles u should know that, its been sitting in ur shop for 7 months now

3.492rs

naaa there pretty hideous for gas mileage on the free way

87TPI350KID

True, if you ditch the TPI (which 99 percent of the people wont) then you can run 4.10's.

4.10's + TPI = Tire Shredder or Fastest 40 mph drag car.

mustbeatmopar

my friend had a 4.10 in his 88 t/a when he got it. its a 305 tpi. he tried to pass me from about three lenghts back one time, by the time he got up to my door, his car was winding out. i just kept accelerating. thats the only time my 3.1 bird beat him! lol. he swapped it out for a 3.23 soon after, now his car dosent shut down at 80.

urbanhunter44

iTrader: (3)

it had shorties, a new cat and a catback, how is that not full exhaust? and it had a chip, albeit a crappy one.

And my gas mileage is fine, its about 23 mpg highway now.

urbanhunter44

iTrader: (3)

exactly. I wouldn't really go beyond a 3.4x gear for a street L98 car.

Maybe for a ported out/siamesed runners/chipped with better shift points L98 then I might consider 3.73s.

Under no circumstances 4.10s.

3.492rs

shorties yes, stock cat, stock 2.25in pipes, blowmaster muffler= not full exhaust. chip hypercrap=stock tuning

urbanhunter44

iTrader: (3)

Those aren't stock pipes under your car, wtf are you talking about?? They're 3" pipes. And even if they were stock pipes, the stock pipes on an L98 IROC are 2.5", not 2.25" smartie.

And yes, headers and a catback is full exhaust.

Hypertech, while being crappy, is better than stock.

87TPI350KID

Call me crazy but the hypertech is much better over stock..

Still need a prom to run super well though

89IrocZ350TPI

I got better gains with Hypertech than a chip from TPIS.... I dont know why so many people bash Hypertech.

ShiftyCapone

iTrader: (7)

Because they add fuel and spark where it is not needed. It is a stab in the dark tune based on "guessed" parameters. You wouldn’t do mail order surgery so why would you do a mail order tune? Hypertech isn't that good but they have enough naive customers to keep them in business. Modern closed loop fuel injected systems need to be in the hands of the tuner to be properly re-calibrated.

3.492rs

2.5, 2.25 whatever its still not 3inch dumbass

89IrocZ350TPI

Hmm idk man it works for me.

80smetalfan

I've got a buddy with a 94 Formula LT1 with an A4 and 2.73s who runs 14.2s+ all day long. What's really irritating about it is that he will sit and badmouth 3rdgens all day long, talking about how there's no comparison between his car and an L98, and he's not really that much faster, if any. I'd love to get a nice well-preserved L98 and race him (though considering he has ignition problems out the wazoo now, it probably wouldn't be much of a race). I've seen a lot on here with the right drivers and bolt-ons that run 14.2's or faster. Even if I only tied him with his car running right, he'd be really embarrassed and look retarded, as he constantly badmouths anything SBC that's Gen I.

urbanhunter44

iTrader: (3)

All things given, a well maintained (even high mileage) 94, A4 2.73 should outrun an L98 from the stop onward. If he's trapping low (97 and lower) then something is wrong with his car. That car should trap at LEAST 98 in stock condition.

89IrocZ350TPI

Why would he bad mouth the L98. The LT1 was based on the L98.

IROCThe5.7L

Thats just something you got to deal with. Some LT1 owners talk down about L98's, and some LS1 owners talk down to the LT1. When it comes down to it Ls1 > Lt1 > L98. Unless you get into internals.


Looks and handling are a different story though

Blu91Z28

Yeah, I love racing these guys at the track! They're the type that talk all kinds of smack in the staging lanes and then have nothing to say after they're owned by several cars on the track. You're right about the A4 2.73 cars being a drivers race. My first race with the Z was a 95 A4 2.73 car and I ran 14.43 to his 14.42. Reaction time still got me the win though! This was with 135,000 miles, K&N's and some muffler shop hack job cat-back in 90 degree heat and humidity. I've since added a few minor bolt-ons but I'm still running factory heads, cam, chip and a ported factory TPI intake.

urbanhunter44

iTrader: (3)

Actually all of those engines you mentioned have the exact same potential. Actually if you wanted to argue a little, the LS1 actually has less potential than the LT1 and L98, all in stock forms.

People that talk **** then get owned deserve it, however just because one guy ran a 14.4 in an LT1 doesn't mean they all run that. In fact I bet if you let me drive that car it would run several tenths quicker. The A4 LT1s run typically 13.9-14.1 trapping much higher than L98s.

80smetalfan

oh I know. I'm not discrediting the LT1. If this kid had 3.73s instead of 2.73s, along with traction, I'm sure he'd probably be more in the range of 13.8s or 13.7s. The only thing that irritates me is that he badmouths L98s, when as stated, his particular car isn't THAT much faster. He's not a bad driver, I don't think, as I see A4/2.73s run low 14s quite a lot.

The difference between us and Gen. II/Gen. III is mainly the fact that their cars respond like crazy to kinda basic bolt-ons.

Blu91Z28

Of course they don't all run 14.4. The majority run 14.2-14.7 around here though. Granted that's usually in the hot and humid Summer! They should have no problem running high 13's-low 14's now, stock. Why is it with your mods you're only running 13.9's? You should be low 13's easy! Maybe even high 12's with me driving, lol. And yeah, the A4 LT1's do trap 3-4 MPH higher than a L98 but best of luck finding one that will cut a 1.9-2.0 60 ft. stock like the L98 cars do. That's why they can run similar times with the MPH difference. You LT1 guys get a beautiful view of 3rd gen tailights all the way to the top of the track! My buddies high 12 second '00 SS M6 sees tailights until right around the 1/8 and then I get blown by like I'm standing still.

cas0484

My auto pulls 2.0-2.1 60' with stock suspension on stock 16 inch wheels. My friend's 95 T/A bone stock cuts the same 60' as well as my other friends 95 Z28. So realistically, at least around my area, Lt1's are cutting decent 60' on stock suspension/tires. Also, I've never lost to a thirdgen on the road or at the track. But I'm assuimg none of them were more than stock to minor bolt on cars. And no, they weren't Lo3's
Anyways, not bashing thirdgens, being a former owner myself I have come to love both and appareciate both of their pros and cons. Started with a Lo3...upgraded to a Lo5, had a L98 for a short time, and now I'm at the Lt1 and still craving more. But I dont understand why people believe its so expensive to mod the 4th gens. For the Lt1's anyways, I bet you'd be pressed to find a more cost eficient H/C package for 1100 that produces 370-390rwhp or a cam/bolt on car yielding 320-350rwhp for a thirdgen.