1998 LS1s... the good? the bad? the gly?... tell me.

[V]

Why do 98 ls1s get a bad rap when it comes to being compared to later models?

I know people claim "weaker" rod bolts,

diff ecm/harness BUT what is truly different? Is it worth swapping to a 99+ harness ecm?

Metal fuel tank

whole coolant temp is 3 wire?? and fuel sender wont work with newer ecms etc.

heads are diff


--My plan is to use a 98 drivetrain as a swap.

I have 241 heads id be using, Then getting ARP rodbolts, custom cam valvetrain etc. electric water-pump, new intake and TB as well.

I'd basically be using the 98 shortblock, oil pan, transmission(t56), ignition coils and front accessories. I just dont know what I should do about the harness ecm. I THINK i have a 2000 ls1 auto harness laying around I could use and repin the t56 wiring from the 98 harness into it, and then just buy a 99+ ecm.

I just dont know the details about why people really hate the 98s electronics. the motor will be a cam/bolt on, nothing insane, and will be tuned using hptuners.

[NJ Torque]

They cant be tuned as SD... and poorer internals (so Ive heard...) but everyone complanes about the head/valve cover setup that can't be swapped over.

[69BirdX]

I always heard the rod bolts and heads were the problem. But as long as you put new arp rod bolts on there isn't much to worth about.

[WSex]

My 98 is being tuned on sd. And stock bottoms can handle 500 crank all day long

[qwikz28]

Perimeter bolt valve covers is a big complaint I hear. That, and the rod bolts.

[coolmanvette75]

The PCM's are much slower. Try loading a tune into one. Takes 5x as long as a newer one to load it in. If you are using it as a swap just get a 0411 pcm/harness and solve that problem. It seems like after changing the heads and rod bolts, the only thing left you will have from 98 is the rotating assembly and block. Nothing to worry about for a simple build...

[V]

Goal is like 400rwhp, will have a cam and aftermarket intake manifold. Once the car is running tuned and reliable, eventually, the rwhp goal will be 500 but that will probably involve new heads and cam.

I tried buying back my '01 SS just to take the motor from it but the current owner will never sell, he's in love with it.

Anyways, before the motor goes in the car, the following will be done..
-Block dismantled and sent to machine shop to be checked and new cam bearings installed,
-ARP rod bolts for stock rotating assembly,
-241 heads,
-aftermarket cam package(new lifters, pushrods, oil pump, dual spring valve springs)
-rocker arms rebuilt with trunnion bearings
-electric water pump
-Fast intake manifold
-90mm(or +) Throttle body
-long tube headers
-ARP balancer bolt, ARP flywheel/pressure plate bolts
-textrailia clutch

Oh, And i may rebuild the T56 too while I'm at it. Just for peace of mind.

As for the harness, I'll use the '00 one I have somewhere and repin in the t56 wiring from the 98 harness, so i'll have a ls1/t56 harness thatll work with a newer pcm.

[69BirdX]

Sounds like you'll have nothing to worry about.

[V]

Got the car home today. Battery is dead so I didn't bother checking anything, after 8 hours of driving I was exhausted.

The motor is said to make a "faint" tapping. So possibly a rod knock but still said to run fine.
Even the trans was supposedly recently replaced or rebuilt. When I pull it out I'll see if I can tell.

And Chris, I blame this '98 on you... lol. At the meet remember I was saying I didn't want a 98 and you said something along the lines "well if one is put in front of you for 1500 bucks, you're not gonna say no..." well, I obviously didnt say no, haha.

[xrelapse13]

98 ECM isn't a problem to tune until you get above 14-15 psi of boost due to the fact that they cannot be upgraded to 3 Bar SD. They can however be upgraded to 2 bar sd and tuned like that with no issues.

They can also be tuned N/A regardless of set up with no issue. If someone tells you they can't tune your N/A set up because it's a 98 PCM find a new tuner.

[V]

I'll currently be running N/A but always with a future possibility of boost for the car, so I'd probably change to a newer ecm based on that.

I also have a pretty decent start-up tune for my build for an '01 ecm(I have hp tuners) and i'm not sure how that would work onto a 98. I thought there was a file writing difference with the 98s too.

The whole motor will be going an a 3rd gen so custom wiring changes will be getting done too (by myself, I will not pay someone to crimp wires for me, lol)

[Firehawk441]

Most important difference when working with a '98 is the rear cover on the block. It, as well as the gasket are specific to a '97-'98 block.

[steverc0034]

My 98 z28 runs good best time so far is a 10.87@123.8 N/A at Arco raceway.

[xrelapse13]

you won't be able to "write entire" to the 01 from the 98 tune, but you can transfer over most of the tables.

[V]

well i dont need to put a tune from one year onto another.
the 98 tune is stock.
I have a modified 01 tune on my laptop already which I'd like to use as a startup tune once I rebuild the motor(243heads/big cam). Hence why a newer ecm might be a plus.

[xrelapse13]

yup, that's what i was referring to. for the most part you'll be able to populate the tables in the 98 pcm with info from the modified 01 tune so you can start it up with the 98 pcm prior to doing the harness upgrade etc.

What i meant was that you wont be able to write the tune to the 98 ecm, but you can transfer over the actual changes within it to a 98 file.

Feel free to pm me, would be glad to help you out.

[V]

ah ok. i got what you meant now. it'll be a long time till i deal with the tune but ill keep you in mind if i have any questions.