I'm talking about the LS series, there should be cast iron blocks from the 98-02 camaro/trans ams. I may be thinking of the lq4, f#*k I don't remember.

I hate the LT1's with a passion lol

 

The LQ4 is a 6.0 out of the suburban. To the best of my knowledge, which is not all the much, I don't think there was ever an iron block LS1 in a f-body. Yeah the LT1 is about as garbage as a 90's 5.0 lol

 

I did a little search, and it looks like you can take a 5.3 up to just over 3.9". That is about as big as you can go with the aluminum block 5.7. The aluminum block can only go .010 over, where the 5.3 can be bored .120 over

 

The stock heads yes. When you get into the aftermarket, the heads really need 3.9" or bigger.

Just to be clear, LT's are Gen II motors, the LS with cathedral port heads are Gen III, and the current LS motors with 6.0L aluminum block and rectangular port heads are Gen IV.

 

Edit: double post

 

Man what a beast. How in the world does that thing pass smog checks?

 

Forget megasquirt. Use the factory loom and ecu with their tuner software. You can totally reprogram them like a megasquirt and it works well since it uses oem type processing and hardware.

 

Wait using something other than HPTunders or EFI Live with an LS swap for under 1200hp was considered? I must have missed it.

 

Nothing has been decided yet. I tuned his MS2/Turbo setup and we were tossing around ideas about the best approach for this monster. Nothing set in stone yet. I'm sure MSPro would get the job done, but using the factory harness, factory ecu, and a well developed LS focused program like the ones mentioned, also sounds tempting.

...I gotta say though: using oem sensors/wiring and an ecu that is already set up for all of it is a really good idea. I don't even want to think about how much time we wasted on the turbo setup just diagnosing bad wiring, bad sensors, and bad ignition components.

 

Thank you sir, for some reason I was thinking there was an engine between the original small block and the LT1.

The car is not registered, it will not be a street car.

As Vlad said, nothing has been set in stone yet. My reasons for going away from any type of stock ECU is the fact that I do not want to screw with a factory harness. All wiring has been removed from this car and I am building an entire harness from scratch. Wiring up a Megasquirt and building a harness for that seems much much easier than trying to adapt the stock ecu and f body harness into the car.

 

The stock GM harness is so close to being a standalone engine harness already though. The only problem is, if its like other GM harnesses I've dealt with it has about 30 rolls of electrical tape on it.

 

That's what I don't want, I want a nice clean wiring job for the whole car. Probably going to pick up a painless fuse block and start from there. Is there a reason in particular not to go with a ms3pro? I know it's a bit pricey but I feel like it would offer more features than a stock ecu could. I may be completely wrong though.

 

An ls based harness would be a minor depin at the chassis to integrate into the miata. So that you have only a handful of wires.

 

You can buy a super cheap standalone harness to run those LS motors on the stock ECU. Thinning out a stock harness isn't that bad, you'll want to do that if you've got a truck harness, moving things for the shorter intake manifold.

HPtuners is pretty legit, and 99.9% of dyno tuners will know it better than megasquirt.

 

What is this dyno tuning you speak of? I'm all about that street tuning with Vlad and scaring the **** out of him lol

Like I've said, nothing is set in stone just yet. I may end up going that route and just buying connectors for the ecu and building from there. Sure would be a lot cheaper I would imagine.

Which ecu in particular would I use?

 

Ha, fair enough!

I think the ECU you use depends on the motor you've got. If that's just a LQ4 the F-body LS1 ECU should work just fine. Can't go wrong with the ECU for the year truck that motor came from, I'm pretty sure they are all hacked and cracked the same as far as HPtuners or EFI Live cares.

I do remember that there are different ECUs for cable and electric throttle bodies, I think that may be the red/green harness switch. You can't run electric throttle bodies on a old PCM, and the new PCMs don't have IAC valve hardware built in, so no go on cable throttle bodies.

If you want some reading material, check out lt1swap.com. Sounds irrelevant, but it's not!

 

I want the throttle cable, that's for sure.

So just tossing out a preliminary list;
-98-01 F body intake and cable TB
-98-01 F body ecu

 

I'd get a LS6 intake manifold at the least, if you've got the funds.

The bees knees for that 6.0 is the newer rectangle port L92 heads off a 6.2L, and a LS3 intake manifold. If you were going to spring for fancy ported heads and all that, I'd at least take a look that way as a cheaper alternative, or just get ported L92 heads hehe

I think it's pretty common for a 6.0 to push 450+whp with L92's and a very streetable cam

 

I don't necessarily know if I need to spend a bunch of money on better flowing intakes and better heads. The F body LS intake fits under the hood whereas the truck intake will not. I think with the heads I have worked over a little bit, LS1 intake and TB plus a lot of boost should get me the numbers. I don't know, maybe I'm thinking about it wrong, if I were doing a NA build I would be a lot more concerned about freer flowing intakes and heads. But I can just turn up the boost lol

Yeah?

 

More or less, but I don't think you'll see 1,000 whp that way, if that was a serious goal haha

If it were me, I'd be boosting a $300 4.8/5.3 with stock heads and a LS1 intake, for sure! Blow it up, get another one for next to nothing and try again. I still hope to do the same myself some day...