daniel thanks for the explonation
but what do you think about the tubular exhaust manifold
will it help the exhaust breath easier too?
is it worth 1000 bucks?
pete

 

Buschur racing has a 3in DP for $300 i think you get a free 3in test pipe if u get a 3in DP

 

I am going with a full Bushur racing 3" setup. I will post the results after its all installed. Dont forget to do a air intake kit as well. www.bushurracing.com

 

do you mean log manifold? These are never as efficient as a real manifold. There was a large discussion on SupraForums the other day about wether or not they were worth anything and they only seemed to make power if running full boost. Setting a turbo for a lower pressure yieled much less power compared to a regular manifold.

 

Do you mean running open wastegate?
Other than sounding REALLY FREAKING COOL/LOUD, I dont believe it gives any extra power.

 

This may help clear up some of the "urban legends". Here is a link to a technical discussion that answers several questions concerning exhaust diameter. It is pretty good and not to technical.

The article is hosted by Vishnu Tuning and I thank them.

http://www.vishnutuning.com/exhaust101.htm

Also, before some folks consider spending $1000 for tubular manifolds, I recommend you first determine you performance goals, then plan the proper parts and install them in the correct order to prevent wasting money.

Speedlimit.........

 

Here is a Q&A from a different thread that you may find useful:

From Shiv @ Vishnu Tuning: "The cat-back upgrade alone yeilded a 10 wheel hp gain over stock with torque gains at all engine speeds. Neither an open intake, free flow cat (or even a test pipe) showed such across-the-board gains. This is why it is a part of the kit. We don't make it a habit of integrating components with marketining purposes in mind".

Follow-up question:

"You mention testing with a free flow cat and test pipe but, no mention of downpipe testing. I have seen much written about the restrictive stock downpipe. I am curious why you have not chosen to replace it with a 2.5" or 3" mandrel bent piece. You can still retain the stock catalytic converter (which is reported to flow quite well) with the 2.5" down pipe in order to meet CARB requirement. Some tuners recommend this as the best bang for the buck mod available for a stock EVO. Do you plan to do any testing here? Seems as though it would be a logical piece to include in your Stage Zero."

Shiv's Response:
"Controlled backpressure testing (read from the exhaust manifold) suggested that the muffler was a bigger contributor to back-pressure than the downpipe or cat. And since knock is the limiting factor when tuning on pump gas, back-pressure (and the resultant exhaust gas reversion) is our biggest enemy."

More info available from www.vishnutuning.com

 

3 inch without a question think of it this way more airflow=more power, 3" of airflow or 2.5" of airflow bigger more air. Hope this helps

 

No, no, no...The downpipe attaches to an elbow which attaches to the turbo. The Evo downpipes do not attach directly to the turbo, unlike WRX downpipes. I vaguely remember seeing a turbo elbow on the Mines site. How much turbulence does this stock elbow cause, and how much will spool-up be helped by replacing it, if at all?

 

My mechanical experience is with Supras only and our downpipes connect directly to the turbo. I would need to see a picture of the elow. Do you mean a flex joint?
Does it look like mesh weave. These are normal as well. How much turbulance they offer is hard to say. In truth you would want the smoothest airflow, but i doubt it would make that much of a differnce so close to the exhaust wheel.

 

No. It's not a flex joint. Go to mines-wave.com and click on Evo VII. You'll bring up a few pictures. One of them is the joint (it's got a divorced section for the wastegate). I think they call it a "coupler." You'll see what I'm talking about. You can also see it in a picture of the Evo 4G63 with all attached piping (sans chassis).