Batass

I just picked up a cts-v with the ls2. 65k miles. I e been holding onto an ly6 for quite a while, also 60k miles.
Either engine I'm going with a mild cam to keep low end torque up. The l92 heads make a bit less low end but gain it back with the VVT. It's also an iron block which is nice for longevity.
The ly6 would need an ls3 intake to fit and completely replace the wiring harness for the e38 ECM and 58x reluctor.

Is it worth the effort to swap? I could sell the ls2 for a nice chunk of change but ported cathedral heads might make the best power curve.

Itll be a DD, shooting for only 500hp, maybe a tad more and I rarely rev over 6k rpms.

bammax

The ly6 is a downgrade. There's no reason to use it over a low mile ls2 at all.

Batass

What about ported 243/stock ls2 intake vs milled l92 heads and an ls3 intake?

The ls2 intake sucks, cant run a truck intake, and i dont want to spend $1000 for a fast. I have the l92 heads, could sell the 243s, and I wouldnt be out much.
Sticking with 243s, I'd be in porting plus at the minimum porting the ls2 intake probably.

Idk. Heavy car and low rpms might really favor those 243s....

Batass

I just discovered the dorman ls2 intake. Sounds like ported 243s and that would be the best option.

99 Black Bird T/A

iTrader: (4)

The Dorman LS2 intake under performed the old Fast 78mm intake in this Dorman LS2 vs Fast 78 dyno test.

A used Fast 90 or used Fast 92 would be better.

Batass

Barely, and the dorman did better under 5k. The ports are a little shitty. I read a little cleaning really helps them out.
I'm not interested in every little bit of power, I just want to do it the way I want the first time. 3 years from now, I dont want to say I shouldve gone square port or shoulve done lsa blower swap.........

I just want 500 fwhp out of it with little low end losses.

bammax

Don't chase Dyno numbers. That's the thing everyone does that leads them into trouble. Build the car for the exact thing you want to do with it and let the numbers fall where they may.

The truth is that you need to do more research on how these engines work. Otherwise you're going to spend a fortune on something that'll never work right.

Batass

I'm really not interested in what it would dyno at. I'm just using 500hp as a rough goal.
My last car trapped at 139 mph and was probably 700hp. I dont need that much.
I've ridden in max effort cam ls2 cars that were maybe 550hp, stock heads. I dont want a huge cam either.
I thought l92 heads were the **** until after analyzing dozens of dyno sheets, that they dont really outperform cathedrals until 4k rpms. But, you can run a smaller cam and achieve the same peak hp. Most of my driving is done around 2-3k rpms.

AI ported heads and a stage 1 cam with a better intake manifold and long tubes should reach my goal of a quick and reliable car, while still maintaining good mileage and long lasting valve springs.
I just dont know what to do with the ly6. Some 5.3 heads on it with the vvt active would make one hell of a torquey truck engine. Not thrilled about swapping out the entire harness and ecm OR changing the reluctor wheel to 24x to keep the wiring and ecm. Theres also some issue with running a t56 with the e38 ecm I think.

If I sound like a scatterbrained retard, well I am. That's why I like others opinions before I build another car that's too wild for the street.

Batass

2:04
Hold The Dang Door! TBSS vs Dorman LS2
YouTube · Richard Holdener
Dec 5, 2019

Here Holdener compares the dorman intake to the beloved tbss intake.

Batass

I just read most of your post on intake flow comparisons. The fast 90 seems to be a vast improvement in power. With alot of dynos I've seen, the fast intakes trade power down low for a peak gain. Maybe those were 5.3s though...
I have shopping to do....

99 Black Bird T/A

iTrader: (4)

That's pretty much what I expected based on the flow test results between the Dorman LS2's & TBSS we tested. It is nice the Dorman has a lower profile and makes about the same power as the TBSS. Of course one can find used TBSS for like $220 or so with fuel injectors & rails.

BTW You may already know about the Lingenfelter 58x crank to 24x PCM conversion box. It works really well if you want to use a 58x crank engine with an older 24x PCM and not take the motor a part. My TA's 416 has one and it does pretty well as a work around.

Best wishes with project

Batass

I forgot about that box. Thanks.
I have to fit the intake into a cts-v so it seems it's either an ls6, ls2d, or a used fast. With a cam and head work, porting or the fast might really do well.

bammax

For the type of setup you're describing you're looking at exhaust, cam, ai or tea ported heads and a good tune. For low rpm power the intake is more of a last step to finish off the package since it's only going to be noticable once the rpms climb. You can go with some really nice aftermarket heads, but it's probably not needed for your goals.

Try to find builds with the flattest torque curve that comes in as early as possible. That's the fun street car build.