insomniac

iTrader: (3)

suprised nobody did that yet...


anyway for our 3rd gens I love keeping it true to the generation and sticking with the Long Tube Runner L98

insomniac

iTrader: (3)

on a side not anyone else notice that on a show on speed channel called "two guys garage" the logo of the show in the opening credits is an L98....

Orr89RocZ

iTrader: (20)

L98's are quick stock in the short distance but easily get out paced by the latemodel stuff Bolt ons they pick up a good bit of performance but after that, stock heads and cam just hold everything back.

Great little motors, I've always liked the torquey powerband on the street... just left alot to be desired on the top end. I had a good time racing alot of cars on the street and even bikes. Lost most but surprised a few.

SDTransAM

iTrader: (5)

My favorite part of the TPI engines, is well the TPI itself (appearance) Other than that, the only TPI engine i've had in the 5 f-bodies I have had, was my 91 Trans am ws6 car, I spent 6 months porting and polishing everything, BBK throttle body, Headers, roller rockers, cam, **** load of stuff, and I lost to a stock LT1 car. I was horribly disappointed.

BLT

I had an 87 iroc a few years back with a 350 tpi... headers and 3" exhaust. I loved that car for cruising around and having fun but it did run out of breath very quickly at about 4500rpm. Almost always would I take the leader off the line but I would get beat up pretty bad on the top end.

Now I have a crate 350 with 210cc intake heads which seems the opposite. It starts to make good power after 4000rpm.. both are fun but a happy in between would be perfect. I'll never forget my TPI

Orr89RocZ

iTrader: (20)

I used to roll race and dig race my buddy's mild bolt on LT1 car. His had full exhaust, 3.73's and stock auto, stock stall. Mine had all the bolt ons. HSR, 1.6 rockers/tune, full exhaust/full suspension, built auto with 2800 stall, 3.42 gears lol

I ran 12.95 he ran 12.96...mine was 103mph his was 107. I was on slicks/skinnies, he was on street tires. Roll racing he'd pull me every time and from a dig most of the time, he'd have a car or 2 on me by the end of the 1/4.

evilemokid94

iTrader: (6)

Does a carb breath better than TPI?

Orr89RocZ

iTrader: (20)

Depends on which carb intake you use and what carb but a performer rpm type intake and a 650 carb or so will out power a stock TPI setup... But I dont think it would do much better if not the same performance as a stealth ram, miniram or full aftermarket base/runners TPI on stock cam/heads.

88fastgta

iTrader: (9)

im doing the same man... staying true to the engine generation built up L98 + T56 equals a super fun weekend car... thats what im shooting for....

danziger

Yep. L98s are pretty slow bull anymore, but still fun...love the throttle-response!

89rs454

Yeah i had a choice to get an l98 or lt1, i wanted an old school torque monster but could not justify the performance, overall stock the lt1 is far better sbs overall, the Ls1 is even better ofcourse but the lt1 is everything i need and more .

Sojer

yall super funny i didnt stay true went HSR but its a LB9 soo im planning on trading mine for a stock 4th SS t56 and swaping lsx 454

89rs454

LSx 454? Care to elaborate?

ninetyone

iTrader: (2)

how does your 83' compare to a stock LT1?

Sojer

Well I have a bit of mods on my car with a little more and a paint job I hope to catch a guy who use to have 1 and want to trade. When I get it I plan on building it around the lsx 454. If u never herd of it look it up and iron block alm ls7 heads 620 hp out the box the long block is about 10k my ls1 will have the intake to feed it on I will have it on the side. The lsx 454 is the same size as any ls motor just with 454 bore and stroke. To reach the 1k ph goal super charger and worked heads and cam. It sould be about 25k to do it

89rs454

Lol i don't have to look it up, just to hear the Sh#t spew out of your mouth is enough. Prove me wrong please.

UnstableAviator

I've never driven an L98 car, but always wanted to just to experience the "low-end torque" everyone talks about. As for throttle response, for years driving carb'd engines I just didn't get it...now with the LS1 I see what all the rage it about, makes a car infinately more fun to drive.

evilemokid94

iTrader: (6)

how are carbs different? the reason i keep popping up in here and asking carb questions is that im trying to build an l31 vortec for my car and i cant decide if i want carb or TPI. im hunting for 400 RHP so from what i can see the TPI wont help me much...

WolfmanTA

I know my car halls A$$. Cheers...

Thirdgen89GTA

iTrader: (5)

The low-end torque is what people talk about, but that isn't where the TPI shines.

Its the MID range torque. TPI's produce mad amounts of torque from 3500-4000rpm, and peak power in the 4400 range. The tuned length intake causes the torque peak to swell like a wave near 3500rpm and it holds it there till 4000rpm or so.

The throttle response is also excellent down low. On the highway with a 6spd a L98 would feel effortless in every gear. 6th gear wanna pass somebody? No downshift needed, just give it a little more pedal and the car will accelerate quite well.

_______________________________

BTW, as someone who has posted in the Drama of that 305 thread, your thread title made me laugh out loud.

evilemokid94

iTrader: (6)

but don't they hit a wall around 44000rpm? Iv heard that they don't breath well in the upper rpm range and aren't good for alot of power like someone like me is looking for

Thirdgen89GTA

iTrader: (5)

The only engines I know that don't hit a wall at 44,000RPM are tiny .21 cubic inch 2 stroke nitro-methane engines.

55,000rpm 2 stroke engine: http://www.youtube.com/watch?feature...&v=BRKDfNN_MnY

But, they don't hit a wall at 4400rpm. L98's just fall off FAST after 5000rpm, there is no use spinning them that high unless you start modifying as several members here have done. Do a search on this sheet for Dyno sheets from a near stock L98 car. They still produce power past 4400. It just falls real fast.

TPI isn't one of those intake you can just slap bolt-on intake parts at and get results. It needs careful consideration, more so than say a short runner intake like an LT1 would.

The best "bolt-on" solution would be the First TPI intake, its expensive but well worth it as far as a bolt-on TPI solution.

Sojer

Its a dream car didn't say next week *** bag ureally **** me off. I sware on my life the races I did were real I nevered lied about not 1 thing I cat w8 to track my car
https://www.youtube.com/watch?v=Bkl1...e_gdata_player

Thirdgen89GTA

iTrader: (5)

You guy's should keep this stuff to the 305 thread and not let it spew into the 350 thread.

Lvgta

I had an 84 Trans Am with a carb back in 1996 when I replaced it with a 1988 L98 GTA that I just dropped a low budget GM crate motor into. The 84 with a carb was spirited for its time, but got blown away by anything sporty with fuel injection. (I remember being embarrassed one night by a Beretta GTZ!) The L98 did jump off the line, but would usually get beat in a race at right around 60-65 mph. The crate motor I just put into it my GTA that I've had for 16 years comes on a bit differently and sounds a bit meaner through the Magnaflow exhaust than the L98 did. Neither motor compares to the LT1 I had in my 97 Camaro, that was my daily driver from 2001-2005, though. It was good off the line but didn't top out until around 150mph. The L98 was redlined on the automatic at 135 mph.

Thirdgen89GTA

iTrader: (5)

I like the way my LT1 feels in my GTA. Plenty of get up and go. I give plenty of stock or near stock LS1's a surprise. The B-body LT1 with its tiny camshaft sounds so tame that alot of people mistake it for a TBI car with an exhaust.

I like the way a L98 feels too. And I loved the 85TPI 5spd I drove as well.

But every generation of small block GM has made since we came out of the performance dark ages has been better and faster than the one before it. The Gen 3 and Gen 4 LS based engines are as revolutionary as the Gen 1 small block once was. There is a very good reason people stuff them into as many things as possible.

kmcn47

if you want good info listen to the experienced guys in your thread and message some of the mods, stay far away from this thread, its the detroit of thirdgen.org

87SLEEPER

Nice vid dude!!!

It's obvious you got mad love for thirdgens. I wanna see it though once its fired up and tearin' up the streets. Keep me posted.

SDTransAM

iTrader: (5)

Haha, my '83 is pretty slow. I got beat by my buddies sn95 mustang that was a stock 5spd. My '83 is a 5spd. I am sure an lt1 car would waste me, but I havn't tried.

My '83 is slow, but I absolutely love driving it.

89rs454

I feel sorry for you, about everything.

Street Lethal

iTrader: (16)

Why does everyone jump on the LSX bandwagon? If you want a 454 just go with a Motown 454 SBC, and reuse your Holley Stealth Ram with it w/larger injectors...

J91

Yeah, please keep this crap talking back on the 305 thread. We should try and stay on topic here: L98, not fantasy LSX or LB9s.....

InfernalVortex

iTrader: (4)

That has a factory deck height and a 4.000 inch stroke, meaning the wrist pin is gonna be all up in the compression rings... and it's $11k. How much does a 454 LSx cost? I really dont know. It may have its wrist pin all up in the compression rings too though.

Street Lethal

iTrader: (16)

The overall package is pricey, but who needs to buy a crate, just the assembled short block. Also, you might have missed where I was going with this, as the whole point of what I was saying is that there is no need to jump to an LSX engine, or any engine above 350 cubic inches, for that matter. Cost? Well speed doesn't really come cheap, not unless guys know how to do their own porting and welding, then it does. As for the wrist pins, these 454 small block engines from Motown have been made since the 90's, and if it was really that detrimental then their own individual warranty would do more harm than good for themselves as a business...

89IrocZ350TPI

I dont understand why you try so hard to get people to believe you. Who cares if they believe you or not.

89rs454

I feel bad for putting it the way i did, i believe he can build whatever he wants. He really needs to mature up a little bit.

RockJay81

iTrader: (1)

I have both a lsx in my 84 and a L98 in my gta. It's like night and day. I'm not impressed at all about the tpi one bit. I'll be swapping it out for a lsx stroker. Anyone want a boat anchor?

Nelz

http://www.gmhightechperformance.com...ock/index.html

I think this would be one of the better examples of an L98 build up. 416HP, 486 ft. lbs. of torque.

The problem is that everyone else now rev's and shifts somewhere in the 6000+ RPM range, meanwhile, the L98, even built up, we shift change lower because the motor stops breathing above 5500rpm. That's why we beat them off the line (if our suspension hooks up-there's way too much torque down low, even stock.)

Street Lethal

iTrader: (16)

Not too many members know how to build them. This was back in 2003, the LSX got loose up top and got off of it, but both cars were built to run single digits. L98 in the further lane. Not saying that L98's are the engines to build, but they are certainly not dogs. Not too many guys build TPI anymore (they're outdated), just like you hardly see that many turbo regals out there. Time always marches on...

http://www.challengevideos.com/2003/...carmen_103.wmv

budfreak1

iTrader: (7)

First thing I did was ditch my stock TPI and according to my math and the dyno sheet, it made me 43 more WHP and 42 more WTQ from just the intake/TB, 24# inj., flowmaster 80 muffler, and a pcmforless tune. It would have made more, but it was running too rich and needed some adjustments, plus it was 85+ degrees out. I haven't dyno'd since then, but I now have every bolt on I can have and will be doing heads and cam soon.
The pic is how it looks now and the dyno sheet was from the time I just talked about 2 years ago.

Vega

I like the L98s myself, i feel like it doesnt take much to make an L98 match an LT1, honestly the LT1 isnt really much more than a top-end swap on a typical 350, and i know theres a lot more aftermarket out there for 350s than there is LT1s. Honestly dont the L98s actually have more torque than the LT1s? Or if not isnt it at least the same? I wont argue an L98 against an LS1 but id much rather have an L98 over an LT1 myself, the LT1 just doesnt have enough of an advantage to make me want it over an L98, its just cheaper and easier to mod the L98 to make more power than it is to do it to an LT1. Also the L98 cars are getting rare so its cool to have a rare collectors item that can whoop on what was built to replace it haha. Along with that same notion the 87-92 Irocs/Z28s that came with the L98s look soooo much better than any of the cars that came with LT1s that that alone is enough to make me stick with the L98. In my oppinion the old school 350 lasted as long as it did for a reason, its a great motor, cheap, and easy to mod. The LT1 lasted as long as it did by the same notion, it was good, but not good enough. Stick with the L98s guys

88WS-6

I laughed pretty hard when I saw the title of this.

88WS-6

I wish the PO of my IROC hadn't swapped on a carb

TTOP350

iTrader: (8)

Looking at this pic, I'm wondering why you used the older fuel lines that route kinda over the header?? Looks like you could have used/left the newer fuel hard lines and made a quick bracket to properly hold them..

Street Lethal

iTrader: (16)

Agreed, I see vapor lock being a serious problem on 70+ degree days...

89rs454

I'm going to race my brothers l98 tomorrow, He has a holly highrise intake, and Vortec heads and a 600cfm holly carb in his 82 z28 stripped down with boom tubes coming off the headers. I have a stock lt1 with 3inch catback, CAI, I will get it on video.

Thirdgen89GTA

iTrader: (5)

You are correct in that the LT1's don't quite have the aftermarket of a TPI based car.

However a great many SBC parts work IN LT1s, so the LT1 doesn't need as much of an aftermarket since it shares it with SBCs.

The LT1 intake needs no replacement, porting it is sufficient for 9 second cars.

The heads being aluminum and common and there are plenty of people who offer porting packages for the stock heads. Not many packages for SBCs, usually you have to go aftermarket which is an investment on its own. Vortec heads make great bang for the buck though.

LT1s use the same exhaust parts as L98's so if it fit your thirdgen when stock, it'll fit the LT1.

Granted, the Gen3's are better in every way, but if you swapped an LT1 in, you haven't been left out in the cold.

*BTW, Yes, L98's do make more peak torque than an LT1 car does. But an LT1 makes more average torque throughout a larger powerband. Its always give and take with similar engine designs.

kmcn47

well if your just giving it away, i'll pay shipping

89rs454

I think your being a bit disrespectful man, the l98 is a champion in my eyes and it needs a little more respect around here. The 305TBI is the Boat anchor.

kmcn47

i agree, the tpi engines were always what hot rodders aroundher swapped into there rides, i'd like to step up to tpi, and i cant really say that any onf the engines used in thirdgens where dogs, the iron dukes and 2.8 when not thrashed can last forever, aswell as the 305s, i've heard nightmare stories about the crossfire cars but i've also heard there no harder to keep running then say an old honda with synchronized carbs, and the 305 tbi in my eyes was the engine that made the most sense in the cars at the time, i mean it got decent enough mileage (sure its no prius) it had enough torque to haul the car around (how many people race a dd anyway? i dont) and of course it went into camaros and firebirds, best looking, great handling sports cars out there back then, and even now so i mean no disrespect to anyone, (except people who have swapped in junkyard 70s truck 350s and hacked the wiring harness's and not got new fuel lines or a bigger pump (the guys who do it wrong)