Ted J

iTrader: (4)

I have a few questions about exhaust manifolds for the C5 corvette. What years were they made where you could weld on them and modify them? Also, were they like the f-body where in a certain year the manifolds flowed better than the older ones?

This is just for example purposes but I found this on ebay (don't want to pay that much for manifolds) and it looks like it could be welded and modified which I need for my project. I also need one that has that design so I'm assuming it's from '97 to '99 that they did that maybe?

http://cgi.ebay.com/ebaymotors/1998-...QQcmdZViewItem

Thanks!

Ted

Ted J

iTrader: (4)

ttt, anybody know details about the C5 manifolds?

300bhp/ton

What are you wanting to use them for?

Basically ALL stock OEM manifolds suck regardless of yeah. Also flow rate really isn't the issue. Even the early manioflds (Fbody 98-00) flow well enough for what they are. Scavenging is where power is made and for that you need longer primary length's, i.e. LONG TUBE headers. For an n/a application they are really the only sensible option as they will scavenge in an rpm range that is appropriate for the LS1. Mid and shorty headers do scavenge but in rpm ranges that the LS1 doesn't use (meaning very high rpms).

If you’re in CA then sadly LT’s aren’t an option (legally anyhow). If you stick n/a then there is sadly very little you can do to generate more power from the headers. Shorties compared to stock headers n/a will yield in the region of 3-5rwhp.

If you plan on FI then any tubular manifold will be a good idea. With FI scavenging doesn’t take place and flow rate is paramount. This is where shorty headers will actually outflow stock ones. Ideally you’d want headers with a 3” collector though.

BTW - I think any of the headers can be welded, but I’m not certain of what you are trying to achieve.


Cliff Notes:

-Don’t spend ANY money on stock exhaust manifolds
-n/a applications = long tube
-CA = stay stock manifolds unless using boost
-FI = any tubular header regardless of primary length

Ted J

iTrader: (4)

Custom project where a sniff test and emissions are going to be needed. Don't want to spent $850 on a custom set of LT headers when I can get manifolds for maybe the cost of shipping and get the car running with cats and all the air hookups. I'll fab something up for the EGR since I know the Vettes didn't have an EGR tube. (I'm looking for Vette manifolds for all other ones I've found so far for the LS1 will not work since where they dump is right where something else is.)

Maybe later when the car becomes a full race car then a set of long tubes will be made up and an ORY will be made as well.

Pretty much I'm not wanting to spend big money on this project yet, want to get the car running emissions legal to pass the sniff test and drive it some and see if I like it before dumping big money on a set of headers. Yes I know that most headers can be welded but cast manifolds can't be welded as easily. I know the '98 manifolds for the f-body can be welded but the ones for '99 and up are casted so again, won't be as easy.

No FI planned as of yet. I have a pretty good idea of the benefits of headers shorty vs. LT's and stuff like that. Just trying to save $800 on the project right now for I still need to buy a fuel cell, radiator, and wire the car up amoung other things.

Ted

300bhp/ton

Well I'm not sure I can help much more as you question delves beyond my knowledge. I do know however that the 6.0 truck manifolds are quite popular over here on custom builds (hot rods, engine swaps and such).

Ted J

iTrader: (4)

Won't work, at least the ones I've looked at so far. Most of the manifolds dump or collect together under cylinder 5 and that's about where the steering shaft and rack are located at. (rear steer car)

Thanks for the info though, I'm open to all ideas to try to get an exhaust in the car and get it running.

Ted

300bhp/ton

I'm not sure, but I beleive you can mount the truck manifolds on upside down, left hand manifold on the right bank and vice versa, don't know whether that would help clearing any linkages. I know someone from Ireland that did this to help with clearance.

Ted J

iTrader: (4)

Hmm, interesting... I'm assuming the C5 manifolds would flow a little better than the truck ones though wouldn't they? Something to look into though that's for sure. I'll have to see if the f-body manifolds I have would even work but I'm wondering if the motor mounts would then be an issue. I know the shorty headers that are block huggers that I bought to try won't fit for when taking the drivers side one and putting it on the pasenger's side the collector hit the motor mouting area of the block.

The C5 manifolds I think would work since they dump in the right spot and all I'll have to do is cut the pipe off that curves back and have a new bent one put in place to go around the rack and steering shaft and I could also weld in the O2 in the position I need. I just need to get my hands on some now and I should be set! :-)

300bhp/ton

I think flow shouldn't be an issue. I'd need to check but I'm pretty sure the person I'm thinking off that runs the truck manifold is also using a supercharger and traps 145mph in the 1/4

Sounds like an interesting project your working on, rear wheel steering??? I guess this is some form of off roader?