I have experimented with two different types of manifolds. My first manifold was approximately 18 inches in length and used an undivided flange and an on center 60-1 turbo. Spoolup (10 psi at 3300 rpms in 5th gear) was pretty decent, but not impressive. The engine had a ton of mid range power but didnt' feel any stronger than my stock twin turbo setup in the upper range. My MPH on the drag strip was also identical to my stock setup. I recently ditched this setup and went with something with short runners and a divided flange to give me the top end power I was looking for without sacrificing all my spool. I haven't really had a chance to test out this new manifold yet, but so far spoolup is 10 psi at 3100 rpms in 5th gear, a little better than the longer runner setup. The turbo was the same one used on both manifolds. I simply swapped out my .96 on center turbine housing with a 1.0 tang housing. Here are pics of both manifolds. I have more pics if anyone is interested.

LONG UNDIVIDED


SHORT DIVIDED

 

i think you have tried the opposites of everyone else, normally you have a short undivided or a long divided, hence i think you haven't noticed much difference

 

Since I'm fairly new to all of this, I was wondering how my setup fits in to what you guys are talking about.

I have
Turbonetics 60-1 T04B .96A/R .70 Trim 4"inlet. 42mm Racegate WG, HKS manifold. (Still needs to be installed)


Is this a proper setup. I thought I was told that divided would not help much more then this setup??

Should I have went for a divided manifold? What would the differences be? What boost/rpm/rwhp should I see with this set-up with a ported motor? "Approx"

One last question. How the hell do you guys know this stuff?? Is there someplace that I can read about this stuff?? I spend some time picking out my turbo but everybody had something different to say??????

Ian

 

hahaha you got that right mate

if you want to get into some good books there's one that RICE RACING recommended...its hard going but a good read. The Scientific Design Of Intake and Exhaust Systems. Can get it at amazon.com

either that or just hassle Pete (RICE RACING) ...he's used to it from ppl like me

Cheers
Andrew

 

if you do a search for posts by RICE Racing anyone which is in a thread topic to do with manifold design, turbo sizes etc then read the whole freakin thread, there is normally a lot of good info to be had in them

 

RICE RACING - how did you choose the ID of your runners to be 2" ?

I seem to remember another thread a while back where almost everyone said that they were running 1.5" to get greater exhaust velocity. Did this prove to be too restrictive?

Has anyone played around with the location of where you are plumbing into the main runners to start your wastegate runners? Along those lines, has anyone played with different diameters and lengths on the wastegate runners to see how they correlate with a fixed main runner ID and length? It seems like the main runner length is pretty straight forward, I'm just getting confused about what i am doing when i plug in the wastegate runners. I cant seem to find any good reading on the calcs involved with turbo exhaust tuning especially when the wastegate runners are put into the mix.

Thanks,

 

BDC: What have I been telling you man! Get rid of those crappy log manifolds!!! The 3" rule is how far straight out of the engine the runners should optimally go before turning. This was determined by turbulence through the ports on a flow bench. Try my exhaust sleeves. You'll spool that thing up then!


Brian your intercooler is getting a revision. I wasn't happy with the end tank thickness.

 

Ok. Hey Fred, do you have any pictures of those sleeves? One of the questions I've got concerning those vs. stock is why the stock ones expand in volume by about 2 to 3 times instead of them being left straight? Maybe this has to do with some fluid physics that I'm not familiar with concerning gas expansion, etc.

You weren't happy w/ the IC end-tank thickness?

B

 

B- I believe the stock ones open up like that for a couple reasons. First it cuts down noise dramatically (It slows down the exhaust gases a lot). On top of that it cools down the exhaust gases as well (makes exhaust parts kinda-survive). I believe people were melting turbine wheels with his exhaust sleeves. Got Inconel?

-Manolis

 

doh BDC is interheater is almost ready???

 

The expansion on the stock sleeves was done by Mazda for a couple of reasons. The first being for heat reasons. Slowing down the air does help cool it as well since higher velocity holds higher energy. The other reason is for emissions. This is where an egr passage is. If you look at some of the early rotaries (pre-emissions era) and some of the Mazda racecars, they either have no sleeves or ports almost as big as the sleeves.

The end tank plate thickness was too thin. The volume of the tanks was fine.

 

Roger that. Hmmmm... tempting.

B

 

OK, I have stacks of pics....

I need someone to host them, please send me a PM of your e-mail address and I will forward them to you if you can post them on this thread for people who are interested that would be great

 

picy

 

send them to me peter toffee@world-net.co.nz i'll put them all onto a webpage

cheers
Shane

 

Send some over my way. I'll even host them on the FTP site.

bdc196@attbi.com

B

 

my computer doesn't like ftp's never been able to get them to work nicely

 

Hey BCD I got some bad news for ya. That turbo you are using is your problem ( I had the same one last year). It's compressor and turbine wheels are to thick and to heavy and are not designed for quick spool up.There is just to much mass there to get the inertia.
As soon as I went with a different turbo with a even bigger A/R of 1.32 from Turbonetics spool up was 1400rpm sooner. The manifold was never changed during this swap.

 

heres the pics

 

Thanks for hosting, that was damn quick!

 

Hey Pete, looks very nice. How long till she's back on the road?

 

A little while yet, I need to fab a new intake manifold and IC and Radiator & ........ the list goes on!

It will be good when it's all finished

 

Nice Job Peter.

It's good that you got the wastegate in direct flow of the exhaust gas. VERY IMPORTANT! Most people overlook this when they build there manifolds and then wonder why they can't control boost.

 

RICERACING you mentioned, maybe in another post, that you use the venturi principle on you manifold and downpipe. Do you have any pictures of your downpipe? Is the flange made to match the exhaust port perfectly? You mentioned you are using 2in inner diameter tubing in the manifold. Is that the main runners? If so what is the approximate size of the exhaust port exit? How long is the tapered portion of the manifold? Sorry for all of the questions, I am trying to gather all of the information available before starting on a single turbo project.

 

What kind of motor and porting job was pushing yours?

B