Formula350

iTrader: (3)

(Moved from a different thread to get more views and feedback)

Seeing as I always think of insane ideas that are more stupid than practical... What if one was to use LS2 6L Vette manifolds and flip them upside down and fab up a Down Pipe+Y so the flow doesn't have to go from one manifold and into the next one then finally out to the exhaust pipe?


Yes, I realize it would sit up fairly high.

Hell you could even run them down, like normal, and then just curve it slightly up and over the trans, then down into a more standard Y-Pipe, just the Y pipes would be much closer together, and a 2 piece design ('down' pipe and Y pipe).

Not sure on port match up for these Vette ones, but keeping with the standard down-mounting, and into a Y pipe again. These are LS7 manifolds


These LS3 ones sit a bit lower than the above, and not sure how they compare to the first image. It gives a decent idea of how they size up on the motor.


More info I dug up ("just stfu already" right? :jest) while perusing GM's database of cool info (Like this page) and noticed how the Cadillac LSA exhaust is and it's pretty compact, but has to be pretty efficient to flow what that supercharged 556hp @ 6100rpms. So, it exits right at the base of the last 2 ports, which would save quite a bit more room over the Vette ones above, to curve and go over the trans. The passenger side is a tad longer, but that doesn't matter AS much, and if one wanted (again, assuming they match up on ports) you could use one of those center dump Vette manifolds. If you did, I'd probably use the LS2 pass side, as to not create unfair flow, even if the LS7 would work better. Anyways the LSA:

LSA Heads

(Supercharger shots if you want to try and mate that on the LS4 heh. One, Two)

Now for my second idea, which is more of a question. Can you use a Northstar oilpan (specifically the LD8 or L37 in the Cad DTS) to achieve and Under-the-Motor exhaust as it does?


While they're not headers, they're at least freer flowing manifolds! I'd be happy to photoshop something up if that'd help give you a better picture (no pun intended) of what I'm talking about.

And yes... I finally shut up!

Bryan921SS

Hey so i am not the only one thinking about this stuff!!!

That all looks good, and I too agree about changing the exhaust to run under the trans, then you can play around with pipe diam and maybe even start trying to fit some aftermarket headers for other LS engines.

Formula350

iTrader: (3)

I don't even HAVE a GP and I'm thinking about it haha

I'm slightly thinking that the Northstar might swap, but again I'd have to dig deeper since I know next to nothing about GEN III+ engines.

neilownz

im amazed we dont just have a northstar instead of the ls.

Sint3k

my cadillac has a northstar the 300hp version. The powerband and pull feels almost exactly like the LS4 except i have more torque off the line. Probably because the northstar is dual overhead cams you don't feel it till the end of the powerband.

Formula350

iTrader: (3)

I don't know which Northstar motor you have, and in which car, but here's the 06 LS4 vs the 06 LH2 in the XLR/STS. The LS4 has a much better torque band than the LH2 does, IMO.
If you want a FLAT torque curve for EVER (2000-4800), get the 2.8 Turbo heh
http://media.gm.com/us/powertrain/en...lish_250hp.pdf

Mels SS

iTrader: (1)

I love the idea going under the trans!!

07MCSS

iTrader: (3)

I pondered this idea a few months ago. My idea was to use shorty headers with an oval downpipe for clearance. Shorty headers for an LS engine are pretty cheap. Even the coated ones are cheap.

06WHITEMCSS

I also had a '99 STS, I can confirm the feel. Although the Northstar is a 4.6 and the LS4 is a 5.3, the NS had hp rating of 300, and a TQ rating of 275, while the LS4 is 303 hp, and iirc the TQ of 328. The Caddy is heavier, but way much more luxurious. Almost wish I had it back.

Formula350

iTrader: (3)

Oval pipe is expensive though, and not many shops have the jigs for it. That's why I was thinking of flat out using a NS oil pan since it has so much room (like a standard SBC does).

How about an 04 GTO (LS2 I assume) oil pan? That work on an LS4?


Jackpot! With how that looks, the CTSv pan is a standard LS pan. Would that mean your other avg Northstar pans would also work? If not, then I'd probably go for the Hummer H3 5.3 Alpha pan.
https://ls1tech.com/forums/conversions-swaps/817787-lsx-oil-pans.html

neilownz

oil pickup and stuff would need to be changed i suppose.

LH8 oil pan is 2 inches shorter than the truck one.

https://ls1tech.com/forums/conversions-swaps/857952-new-brp-true-bolt-ls-conversion-kit-1964-1972-body.html

07MCSS

iTrader: (3)

Sorry, I wasn't clear. I meant to get a round downpipe that transitions to oval as it turns underneath the oil pan and back to round to blend back into the exhaust. I found a place online that could do one for about $65. I will post it when I locate it. With a setup like this you could have a true dual option. I was concerned with clearance issues. Looks like you guys have solved that with an oil pan swap. There may be some oil pan pickup issues but I am sure they could be worked out.

Anybody near Memphis attending the LSX Shootout this weekend?

Formula350

iTrader: (3)

Well if there's a good way to transition it, then I say that's not a bad option. I can't saw for sure how good of one it is, since I don't have a LS4 car to look at and gauge ground clearance. In reality, this ALL is a shot from the hip. I don't know how much block-to-firewall clearance there is either for use of different manifolds or creating a different Y-Pipe.

If it does considerably cut into ground clearance, then I'd be a bit sketchy about doing it, and then might look into my Y pipe idea. Basically for that you're completely bypassing the back manifold and having 2 pipes go under into either a single, or continuing on as true duals and not having a Y (as you mentioned). That Y would be a 2 piece design with potential for 3 piece, but 2 pieces would be ideal for less chance of leaks. The to-manifold front and over-the-trans pipe would be piece 1, which would be continue down slight past the trans. Piece 2 would be to-manifold rear and th actual Y. About that same area is where the first piece would mate up with the Y. 3 piece wouldn't be much different, and would be a flange near where it starts to go over the trans and would utilize one of those flanges that has some pivot movement to account for any exhaust movement with engine movement. One could also put that at the Y pipe and then have the over-the-trans pipe have an exhaust 'hanger' bolt to the transmission to stabilize it as if it was still connected to the rear manifold in stock configuration.

And I wouldn't say I have it solved with a pan swap, until it's confirmed a NS pan will bolt right up to a LS4 I appreciate the optimism though lol

I contacted a sponsor who has made a Twin Turbo setup for the G8, to see if maybe they'd be interested in making one of the 3 ideas (which sadly one of my ideas is not coming to mind LOL I have them written down). If they are interested, I'll explain my ideas then, but if not we're back on our own!

ttranssam

iTrader: (10)

i kno this is a stupid question but are there any headers for ls4's??? btw the other day i seen a grand prix that sounded bad f-ing *** after thinking ....i kinda want one

06WHITEMCSS

No headers, won't be any, until someone will let there car be the guinea-pig! I drive mine everyday! Thus I can't be the pig, unless someone will let me borough there car for +2 weeks, or maybe longer!.

Formula350

iTrader: (3)

lol I assume you didn't read the whole thread before asking that, to which yes it was a stupid question Sorry, but yea, I wouldn't have gone through all that typing, and thinking of ideas, for an alternative to headers that are already made. Simply, because my ideas are going to cost on par with a set of headers, and not come up with the same performance.

Yet, on that note, if the NS pan does work, headers wouldn't be hard to do then. Just run the collector right under the pan

06WHITEMCSS

Ya know, you might be on to some ting! Please help us out! We have had some help in the past for headers (I won't mention his name, but I think his new name is FastLS4) search! Well he did try, and tried. to know avail.

nighthand

I wish I could donate the time and money to being the tester for headers. Heck, I need to make arrangements to get my TB ported. That being said, if someone makes a set and keeps the price around $1k or so, I am down. I added my name to a list made a while back that was needed for 10 names or so. I think we got up to 8

I had my heads tested and ported on one of those $100k air flow thingys (cannot for the life of me remember the name - CFM??? I dunno).

If I did not really want a vette, I would be working on saving up for a lot on this one. I would probably retro the whole thing for RWD . (I just cannot get into the look of the G8).

Formula350

iTrader: (3)

Well, what's nice about the way I'm going about it, is the fact that these are factory parts that can be had easily. Cheaply, not sure, except factory LS7 manifolds, since I"m sure most Vette owners have gotten headers (or well maybe *shrug*). eBay's showing a set with no reserve, 1 bit, at $20 heh 7hrs left and I think if anyone here wanted to start gathering parts to try my wacked out idea... This would be the ideal auction!
http://shop.ebay.com/items/_W0QQ_nkw...Q_fromZQQ_mdoZ

07MCSS

iTrader: (3)

I talked to a Kooks rep last year at the LSX Shootout who said that they could make a one off set of headers for our cars for about $1000. He said that they obviously would need the car for a while though. They had many of their products on display. Their work looked really good.

A Comp Cams rep also said they were developing a cam for our cars. I called a few weeks later and was told that it was still in development. I called again and was told that the project did not exist. I offered my car for some R & D, he said no, they get new cars from other sources. Guess where.