schpenxel

Has anyone gone from Z06 manifolds/cats to longtubes on a FI setup? I'm seeing about 12psi right now on an ECS kit.. still on factory Z06 exhaust system with cats. Considering longtubes.

Does anyone have before/after numbers without any other changes? What were the gains?

The Z06 setup looks like it would flow pretty well, but wondering how much I'm leaving on the table without long tubes.

1MEANGS

I think after 600 wheel you could really benefit from making the car breath better... I have the Pfadt 1 3/4 stepped headers and there a work of art & treated me well. Gonna have them for sell now if your interested.

Detoxx03

Mine didn't pick up any peak numbers but it shifted my powerband up in the mid-higher rpm range.

greatgonzer

I am stock headers with Cam and ported heads running ECS kit. I made 650wheel HP.

My buddy has my exact same setup, except he's running headers and milled out the ECS restriction plate a couple of mm. He's pushing 745 wheel hp on that setup.

schpenxel

Good info

grocerygetter

I tested this without cats on a 2010 camaro. Car made low 600whp before headers with stock ls3 manifold and cat delete. We added kooks headers and gained 5%. I could pulley down for way less money and get that. I think once you add a cam, it's not a bad idea to do headers. But the ls7 manifolds out flow the ls3 manifolds.
I use ls7 manifold, z06 x pipe, then custom 3" the rest of the way out the back (auto car....had to be built).

schpenxel

Good info. Yeah, 30rwhp doesn't really seem worth it. The Z06 manifolds do look like they'd flow pretty decent. Maybe longtubes matter less on FI setups?

Detoxx03

The lack of restriction makes it worth it. Don't buy LT's for peak power gains.

schpenxel

Wouldn't a lack of restriction make more than a few % difference in power? Or is there another advantage? I have had a person or two tell me they can run more timing without any issues when using LT's, I'd assume from getting hot gases out of the cylinders better but I don't really know

Spoolin8

Your reducing backpressure, thus reducing heat.

grocerygetter

Yeah....but we are at a balancing point at 650-750whp from what I have learned. To make boost you have to have something to push against. That's why changing to a cat less long tube will typically drop boost. I'll stick to the plan on my car and not get long tubes unless I go with a major cam change. My combo is rockin for now...don't want to screw it up. We have a local 1kft track and on a 1.4 60' I'm running 8.3 at 126mph. That's good for a 9.8/9.9 in the 1320' with my 2.56gear.

schpenxel

Boost is just a measure of restriction. Boost going down because of less restriction doesn't mean less power or airflow goes down, it just means less restriction.

I'm going to get mine on a dyno and see where I'm at first. Even if I do eventually do LT's I want before/after #'s to see if it was even worth it

grocerygetter

Right...I think of it this way, if I put them on and drop boost but still make the same power it's easier on the engine but hard on my pocket book. But, if I pulley down to put the boost back at the number before I could have just dropped another pulley size and saves time and or labor. Lol
But an aggressive cam changes things on whether or not the longtubes have a lot of value or not.

schpenxel

I've got a fairly mild cam, I think anyways. 220/240, around 600 lift, 117+3. If I were doing it over again I'd probably go a little bit more aggressive on the cam but I'm not doing that job again anytime soon.

Ah well, sounds like not having LT's isn't the end of the world. I'll get some dyno time lined up first then go from there

Lateforwork

I'm interested in the results since I picked up a all Stock GS with an A&A Blower. Was considering LT, Meth and a smaller pulley. Let me know what you come up with.

LSX228R

Mine was at 540rwhp (mustang dyno). Saw a few of the same exact setup with long tubes and they did 560rwhp. Made more power everywhere I believe. Def sounded better lol

grocerygetter

Fact! sounds better for sure!

grocerygetter

meth+boost=a lot more power

Nosferatu333

The sound change going to lts is worth it alone. It's incredible if your into that thing. Couple that with the power increase makes it a no brainer for me. Going further the weight reduction from the cast manifolds makes it an all around must have upgrade. They look great as well. Get the damn lts.
Don't let money influence you. The kit cost about 6k add install and tune, clutch and your looking 10kish. Great power added for sure but offset the weight penalty of the kit. All things considered the price of lts isn't bad.

schpenxel

Speaking of which.. I've been meaning to add up what I've spent so far but haven't gotten to it yet. I'm not sure if I really want to or not even though I'm sure I've spent less than most

Ok ok you talked me into it, maybe I'll do LT's