DavidGXP

iTrader: (14)

LS2 Corvette exhaust manifold


Stock LS4


I'm thinking of buying the Corvette exhaust manifold and adapting it to our LS4 in order to eliminate the need for the crossover pipe having to dump into the rear manifold. All eight cylinders flowing through one manifold is kinda of restrictive IMHO.
I'd have an exhaust shop fab up a small Y pipe to the stock downpipe. (From the crossover to a section of exhaust pipe coming out of the new manifold)
The stock manifold has the collector in between cylinders number 6 and 8. The LS2 has the collector exiting between 4 and 6. I'd like to think that this would allow a little freedom for an exhaust shop to get creative with a custom Y pipe. I'd like to keep the stock front exhaust manifold and crossover. I'd probably get a Lokar flexable trans dipstick tube to aid in clearance. I don't want DT headers. I like getting creative with stock parts.
What do you fabricators think?

fieroguru

iTrader: (1)

Give it shot! You biggest issue will probably be clearance to the transmission. The LS4 manifold points more outward to the rear vs. the LS2 that points pretty much straight down.

You might want to conside the early LS1 vette manifolds as well. They are stainless steel and relatively easy to cut up and reshape to clear the transmission:


Here is an inspirational shot (but it took quite a bit of work for the LS7 manifold to clear)...

DavidGXP

iTrader: (14)

Ha.. ha! I was viewing those pics that you posted before. The LS1 vette manifolds were going to be plan B. I like the short exit path on the LS2's though. I'm going to take my car into a shop tomorrow with pics of the LS2 manifolds and see what they think they can do.

CenTexSS

iTrader: (2)

Do it.

DavidGXP

iTrader: (14)

In the works man..
I've been under the hood with the car up in the air and everything looks promising! Really depends on the LS2 outlet angle.

DavidGXP

iTrader: (14)

CenTexSS

iTrader: (2)

I hope it works. I wonder if the cost is worth the end result. Maybe get a vendor to make a bolt on part in the future!

DavidGXP

iTrader: (14)

Possibly yes, I will talk to Dan, at Clear image automotive.
15hp 15 ft/lbs?

DavidGXP

iTrader: (14)

Green box is the restriction
Basically we have 4 cylinders flowing into cylinder number 8's primary. Lucky for us we have very little valve overlap. GM did a pretty god job though.

evil 5.3

just curious why anti headers for the car

Battle_Ravage

Are you asking why people don't make them or why some of us don't use them?

I won't use the DT headers because they aren't turbo compatible.

DavidGXP

iTrader: (14)

I'm not totally... anti. I just don't wanna spend 1000.00 and the group buy thing is going to take awhile. Headers are a little much for our engine till we cam and can get some serious air flow threw a LS6 intake. More compression too would help as well.
I had the headers and I hated the whistle (fixed now I guess?) and the leaks from the clamps and front collector pissed me off. On a stock engine the headers aren't showing huge gains.

I like being different man.. This is why I have a front wheel drive 4 door V8 LOL

evil 5.3

by no means am i laughing at what you are doing just curious . i considered running the front pipe under the oil pan and running duals with an x pipe but mabey not the best thing to do lol

evil 5.3

sorry i was asking why he seem anti dt headers

CenTexSS

iTrader: (2)

Not to mention the DT Headers primaries are quite large for our cars.

I'm very curious too see how this pans out, looks promising!

crazyjoe

Interesting to say the least, I'm definitely looking forward to see how this works out.

nmp0098

Dave, don't forget that only two cylinders are on their exhaust stroke at any given time, and they are 90* out of phase. That means that only one cylinder is pushing exhaust at peak flow at any given time. It's much less restrictive looking if you don't think of all cylinders flowing at once.

Still, I like your plan.

And like I said in the other post, there is a lot low lift overlap in the stock cam. Of course, not so much at 0.050".

Yeah, I don't like how large they are for being shorties. Given the clearance issues and the fact that the O2 sensor is moved farther down stream, I'm not sure the gains are worth the $$ and annoyance cost. The closed loop switching delays get jacked up with the headers, and the old ones didn't clear the better intakes without have to spring for an adapter as well. Granted, since I've completed my swap others have tried different methods with generally better success.

DavidGXP

iTrader: (14)

Talked to a fabraction shop today, and the main exhaust guy thinks he can make it work. I have to install the manifold and get the car down there though. (open exhaust?) I'm going to order the lokar flexable dip stick assembly and some flanges. I'll yank the exhaust manifold off next week and we'll see what happens from there.
Keeping my fingers crossed!
Next mod will be getting everything ceramic coated.

DavidGXP

iTrader: (14)

http://www.exhaustvideos.com/faq/how...pipe-diameter/
Cool reading.

DavidGXP

iTrader: (14)

Roger that!