88 WS6 TransAm GTA

iTrader: (1)

On a single turbo setup that uses a log style manifold on the passenger side, what would be recommended for the drivers side? Im thinking another standard manifold, to equal out pressure between both cylinder banks, as the turbo side would obviously be less efficient than a header. But I have no technical info to back this up... lets hear your opinions!

Greasemonkey

I'd just use a regular shorty header. The flow from both sides has to go through the restriction, so I don't think you'll have a problem with uneven pressure distribuiton.

biggtime

I think he only planned to run the turbo off one side of the engine. I would do like you said and run another stock manifold to try to even out what the exhaust *see's*

deadtrend1

iTrader: (1)

<- 88 WS6 TransAm GTA here...

The turbo wont be run off only one side of the engine. The turbo mounts to the passenger side manifold, and the drivers side manifold/header is connected to the turbo manifold via a cross-over pipe. Just looking for recomendations here, as it would be easier to get an L98 exhaust manifold than to find only one header.

TTA850

If you want to use a stock manifold it will work fine,Buick turbo V6 motors use this style setup well into the 10's.If you want to run a header on one side it will also work fine,as TTA use that type of setup also into the 10's(my car is a good example).

HTH,
Steve

88 WS6 TransAm GTA

iTrader: (1)

Thanks Steve. And if it works for GN's and TGTA, then it should work just fine for me!

Next question... whats the best flowing exh manifold?

Guido

There has been debate on the L98 logs vs the TBI/RS/Base Z28 manifolds. I think someone actually did a comparison once and the opening on the L98 manifold was larger. As funny as it sounds that it would even happen.

You might do some research. Make sure you plug those AIR tubes though. LOL And a dremel around every port couldnt hurt anything.

88 WS6 TransAm GTA

iTrader: (1)

Yeah Im definatley going to "clean" up the manifold lol. Once everything is fabbed up like the crossover and downpipe, Im having it ceramic coated (2000*+ coating).

The main reason I wanted to use a manifold was that it will look symetrical, and take up less space. I know looks arent important to everyone, but I want this to look good as well as function correctly.

Fevre

Not sure if they would work but the old rams horn manifolds are supposed to flow the best of any cast iron manifolds. There was a turbo one on e-bay not too long ago that someone posted about.

88 WS6 TransAm GTA

iTrader: (1)

Ive heard the ram horn manifolds will hit the crossmember, but not 100% on that. Besides that, if I used a ram horn Id have to make the crossover slightly longer as it exits in the center vs. the L98 rear exit, causing a loss of velocity. Im trying to make this efficient as possible to get the most out of the setup... its not the best flowing setup, so Id like to atleast have velocity on my side.

83 Crossfire TA

iTrader: (2)

I'm not sure what you're saying there.

Having both sets of v8 3rd gen manifolds around, they're identical besides the actual outlet (one is roughly 2.25" and the other is about 1.75"). REALLY, for an under 500-600hp or so setup I bet that you won't see a difference between the 2.

Ports that increase in size for no reason hurt flow. Thinner walls will allow more heat to escape, and inconsistencies in casting thickness will cause cracking when you get it hot. I wouldn't do any cutting that you don't need to.

depending on where the actual outlet on them is, they might fit, but a normal block hugger won't (the outlet and the front primary will hit the motor mount/k-member.

The 4th gen f-body/b-body LT1 manifolds are lighter and flow better then every other cast manifold that I've seen, they are cast a lot like a set of 4 tubes that actually direct the flow toward the outlet, unlike the rest, which just sorta dump each port into a straight or curved (rams horn) log and just hope it figures out which way to go. The problem would be that the LT1 D-ports are smaller then the exhaust ports on all the traditional SBC heads that I've seen (much smaller then the ones that I just pulled off of my '83 305, which are smaller then the L98 ports) and they use the wide/outside bolt holes that not all small block heads have on the end ports (and would interfere with some accessories, like whatever is on the front driver's side on your 3rd gen).

As far as where the exhaust connects, most small block manifolds connect the passenger side at the back of the manifold and the driver's side between 5 and 7, closer to the center, pointing straight down.

Like I've already said, I really doubt that you'll see much of a difference no matter what you use, there will be enough pressure in there under boost that you'll be able to force what you need through any reasonable opening (there's a mustang kit that people have made over 600hp with that forces ALL the exhaust from all 8 cylinders to flow through a 1.75" hole).

My criteria for choosing something would go:
- what do I have sitting around (both manifolds and matching flanges… If you start having to buy flanges to match xxx manifold you'll find that your costs shoot up quickly… flanges are expensive unless you make them yourself.
- out of that, what will be the most durable
- what can I sell on ebay for the least (might as well sell off the extras that are actually worth something.
- what will give the best clearance to work on the thing