Hustler's turbo-talk debate series: tubular manifolds turbo mounting
 

Should the turbo mount on top or below? Why?

boost logic likes to put them on top for every car they build:
http://www.boostlogic.com/images/par...boPosition.jpg
runner #4 is lol
http://www.boostlogic.com/images/par...aManifold1.jpg

BEGi mounts them on the bottom:
http://www.bellengineering.net/image...e/P2213262.JPG
so does AMS:
http://www.amsperformance.com/cart/i...P/tkit1-01.jpg

It's all about the space you have to work with and the preference of the builder.

When I was at Hennessy a few years back, John and his team were debating the placement of the turbos for the 3rd gen viper. It all came down to clearence, "smoothness" and efficiency of the system. It ended up making since to place the turbos under the car, slightly back towards the rear, flanking the motor, to get a straight shot for the side exhaust and a clean intercooler piping flow.

On the other side, a friend of mine just got his evolution 9 back from Central Florida Turbo with a FP Red and the manifold places the new turbo waayyy the fuck down there. If he ever has a problem....he is fucked. It is nearly impossible to comfortably get any kind of tools down there. I hate working on that car:fawk:

I say the top mount is the best just because of the ease of getting to the turbo system. But, if you have the clearence(no a/c, p/s) then go for a bottom mount and have the smoothest downpipe turns ever. I know Corky has a beautiful design that clears both a/c and p/s but I would go crazy trying to work on the car.

Just my :2cents: PLEASE BE GENTLE

I'm looking at making new hot-side pieces with v-bands and these are all good considerations. My goal is the most simple, reliable, easily accessible product.

if you're putting a V-band on the turbo-mani joint, it doesn't matter. the moment arm on the head flange is pretty much the same.

I'd go bottom mount so your downpipe is straighter and easier.

I've talked to one person who said v-bands could warp...I then created this thread. I want to eliminate all doubt this time around because I'm very pissed-off at the moment for not respecting this issue years ago to blow money out my ass today.

Hustler has 5 posts to go to reach 10k... what does he win?

I have nothing constructive to add here, but I would think 95% of the consideration of these pieces would be packaging. The Miata has got to be up towards the top of the list with "enough room to do whatever you want"... especially with an AC/PS delete. I can't imagine needing more room. You've got enough to top-mount a 3071... just some heat shielding for the hood and a little cutting of the rear fender-seam for some DP clearance.

I see all these pics in the various mags of Supras/EVO's where the uncoated turbine housing is 1/8" inch from something you don't want melted and they're happy to get even that much room.

My reasoning as well.

The stresses at the head flange will vary with the distance of the turbo out from the head, but will not be significantly different for a turbo above vs. below. So long as turbo not hit block, a bottom-mount will make your down-pipe a more direct shot.

bottom = you put the weight lower (better for cornering) and your downpipe is straighter ...

http://www.cardomain.com/ride/737924

A local guy's car. He drives this thing to tracks all over the west coast. Note his tubular bottom mount and Vband turbine exit. I'd go with it.

I probably shouldn't even mention this at all, but hell why not.

Just got a wild idea.

Why are all turbo manifolds made with the turbo flange being horizontal to the engine?

If there isn't significant reasoning for that, why not have a shop make you one that is a top mount for the easy access benefit, but with a diagonal turbo flange (v-band in your case), so your DP would only need about a 30* angle instead of a 90*?

I call this: thinking outside the box. Often accompanied by: being completely wrong.

I recall raising this question a year or so ago, and the answer that Corky and others gave was that it was necessary for proper oil drainage that the CHRA be no more than some relatively small number of degrees away from horizontal.

you can rotate your turbnine housing to point the CHRA any way you want...

incredible work.

Its cool to see that I'm not asking for something impossible.

Re: "with a diagonal turbo flange (v-band in your case), so your DP would only need about a 30* angle instead of a 90* "

I interpret Project84's suggestion as meaning that the turbo flange be angled such that, when viewed from the side, a line drawn through the axis of the turbo shaft is not horizontal. Such an arrangement would ease downpipe construction, at the expense of oil drainage.

I wondered if that was the reason, but I figured a little diagonal wouldn't bother much.

Edit: Joe, you nailed my idea. Wayne, once you break horizontal, and your turbo is mounted a little "tipped" backwards toward the downpipe, the CHRA wouldn't be vertical anymore. Rotating wouldn't help make it more vertical.

Ahh, I see. No, I would not do that lol.

Yea, he was at the last local autox looking at my BEGi SSSGDP telling me he cracked tons of those over the years on the track. He also helped me fix my car at lunch when the slip joint in my DP came a part. Awesome guy, super fuckin smart. Knows his shit.

Also, he shows up at the autox's in his "slow 323" and takes fastest time of the day every time over several extreme prepared cars.

I'm looking at putting 2-flex sections in the next DP. I've been thinking about getting on the brakes at the track and all the weight of the exhaust. When I yanked my turbo out I could push the downpipe roughly 2" forward by pushing the tail pipe. Maybe I should hard-mount the exhaust to the PPF? Going from 130mph down to 30mph twice per lap, for roughly 60-laps might be worthy of some consideration.

My ETD shorty tubey mani has it at ~ 45*.

pics? nay sayers?