big chute turbo build

Koby · Aug 29, 2012

i went with the turbo dynamics down pipe to a straight pipe, full evo kit, ice age rails, CE 2.5 X 174, XXXmodrod vents, bumper & board inserts & CR tunnel extension, cutler weights & spring, and some other chit I can't member.
gotta love ripping apart and cutting up a brand new sled !

JustBoostIt · Aug 29, 2012

Divorced dp

nosajlleb said:
Being the BMP is not divorced does that make a difference?

A divorced style 2.5" dp is 7-9hp gain over stock. An after market non-divorced 2.5" dp will still be an improvement over stock as the stock gets pinched down 1.8". I know some early buyers last year didn't realize the difference in the two and bought the brands that were $100+ less, only to find out later they weren't divorced.
Evo's will all be divorced in their 2.5" and 3" dp's.

Turbo11T · Aug 29, 2012

JustBoostIt said:
A divorced style 2.5" dp is 7-9hp gain over stock. An after market non-divorced 2.5" dp will still be an improvement over stock as the stock gets pinched down 1.8". I know some early buyers last year didn't realize the difference in the two and bought the brands that were $100+ less, only to find out later they weren't divorced.
Evo's will all be divorced in their 2.5" and 3" dp's.

With some skill a guy could easily take the None divorced downpipe and add a divider. But your going to need a tig welder and some metal working equiptment and some ability.

I find it so amazing that cat left so much on the table with the 1100. Extremely restrictive and heavy exhaust. A BOV that does not function properly. I just don't get it. But I am glad that extra hp is made so easily with bolt on's

nosajlleb · Aug 29, 2012

JustBoostIt said:
A divorced style 2.5" dp is 7-9hp gain over stock. An after market non-divorced 2.5" dp will still be an improvement over stock as the stock gets pinched down 1.8". I know some early buyers last year didn't realize the difference in the two and bought the brands that were $100+ less, only to find out later they weren't divorced.
Evo's will all be divorced in their 2.5" and 3" dp's.

So if its not divorced then what is the hp # going to be or isn't there a difference between the two? This seems to be a big question out there, if your tab is only going down the pipe a few inches hows that going to be different from the non divorcees?

Turbo11T · Aug 29, 2012

nosajlleb said:
So if its not divorced then what is the hp # going to be or isn't there a difference between the two? This seems to be a big question out there, if your tab is only going down the pipe a few inches hows that going to be different from the non divorcees?

The advantage of a divorced downpipe is that the exhaust gas coming off the turbine wheel is very wicked. Imagine that little turbine wheel spining 150,000 rpm. Separating this flow from the wastegate is crucial. And having it re-enter the flow even a couple inches downstream is good. I would likely guess that a Non divorced DP in 2.5 would likely be 5-6 hp and a divorced style would be 9-10hp gain.

Like I said you could add a separating section in the downpipe shown above quite easily, Especially if you had the turbo off the sled already.

HOOCH256 · Aug 29, 2012

I dont know much about these sleds but i know a lot about forced induction and i can tell you you want either a divorced or my personal favorite is the screamer pipe! All my turbo vehicles i run screamer pipes and honestly they dont add a lot of noise cause you really only hear it at full boost and by that time the motor is just screaming so its really hard to even hear it above the exhaust note! Sell that and go divorced or screamer!!!

Turbo11T · Aug 29, 2012

HOOCH256 said:
I dont know much about these sleds but i know a lot about forced induction and i can tell you you want either a divorced or my personal favorite is the screamer pipe! All my turbo vehicles i run screamer pipes and honestly they dont add a lot of noise cause you really only hear it at full boost and by that time the motor is just screaming so its really hard to even hear it above the exhaust note! Sell that and go divorced or screamer!!!

Screamer pipe= Wastegate portion separate all the way out without a muffler at the end? Right?

ND · Sep 3, 2012

Turbo11T said:
Screamer pipe= Wastegate portion separate all the way out without a muffler at the end? Right?

Yup. In the mitsu world we just called it an external dump. Sounded like a raped ape. Good times on the freeway

voodoo · Sep 4, 2012

Turbo11T said:
The advantage of a divorced downpipe is that the exhaust gas coming off the turbine wheel is very wicked. Imagine that little turbine wheel spining 150,000 rpm. Separating this flow from the wastegate is crucial. And having it re-enter the flow even a couple inches downstream is good. I would likely guess that a Non divorced DP in 2.5 would likely be 5-6 hp and a divorced style would be 9-10hp gain.

Like I said you could add a separating section in the downpipe shown above quite easily, Especially if you had the turbo off the sled already.

I agree divorced is better but I don't think the little divider you see on some of the outlets is worth 3 HP or more. That has not been proven on any independent Dyno. I'm sure the companies making them will tell you otherwise.

O.B. · Sep 4, 2012

Well got turbo set in. Not very far along yet just no time. Also got the 38 stance kit on. Also got a diamond s hood to help let some of the hot air out.

madmax · Sep 6, 2012

There will be a lot of killer 4-stroke machines on the snow this year. You will love the BC turbo.

Matte Murder · Sep 6, 2012

That exhaust manifold is such a clean install compared to a two stroke pipe. Nice and compact and strong. Is anybody port matching or extrude honing the stock exhaust manifold or even building an aftermarket exhaust manifold? Wonder if there is any horsepower to be found there?

Sage Crusher · Sep 6, 2012

voodoo said:
I agree divorced is better but I don't think the little divider you see on some of the outlets is worth 3 HP or more. That has not been proven on any independent Dyno. I'm sure the companies making them will tell you otherwise.

There is not much advantage to a divorce pipe at the higher elevations?
With so thin air we will never see the spinning speeds to take advantage of a divorce.

JustBoostIt · Sep 8, 2012

Divorced dp's

Few things to consider....

1. A ddp will have a greater positive hp impact the more volume of air you force thru it, ie. bigger turbo. It will have less positive impact adding to stock for sure.

2. There is no denying the advantages of a bigger dp in general. The riding characteristics are noticeable when it comes to turbo spool. Turbos are all about air in/air out. I doubt a cold air intake makes power on the dyno but in how it changes the responsiveness of the turbo is noticeable.

This isn't really about wether the divorced ads 2hp over non divorced IMO. Motor builders and tuners know the benefits of being divorced, I know it's the best option so that is what I'll reccommend. I will admit there are varying designs of the actual separating of the air, but most of that is budget considerations.

ND · Sep 8, 2012

Sage Crusher said:
There is not much advantage to a divorce pipe at the higher elevations?
With so thin air we will never see the spinning speeds to take advantage of a divorce.

Actually at elevation you'll be spinning the turbo at a higher rpm to make the same boost pressure (Meaning the actual pressure of compressed air).
Remember your ambient pressure is lower then at sea level, this means that the turbo had to work at a higher pressure ratio (boost pressure in charge pipe divided by atmospheric pressure) to achieve the same boost level. Higher pr means higher shaft speeds.

Hillclimbpro · Sep 10, 2012

Picked up the rest of my stuff from Evo at haydays and finished the build when I got home. It is on the verge of coming to life again, all it needs is exhaust and some fuel. It was defiantly a fun build and cant wait to rip this thing. With the step by step instructions Evo provided it makes it a whole lot easier for someone to do them selfs. Also every time I had a question I was able to get ahold of Jim right away and would answer every question I threw at him. So between the quality product the well made instructions and prompt customer service I would recommend them to anybody. Here are the final pics of the build. Once the exhaust comes ill take one of that.

Evolution Powersports · Sep 10, 2012

voodoo said:
I agree divorced is better but I don't think the little divider you see on some of the outlets is worth 3 HP or more. That has not been proven on any independent Dyno. I'm sure the companies making them will tell you otherwise.

We are doing back to back dyno runs with identical exhausts - one with an exhaust divider and one without later this week. We will post unbiased results. We are going to put this to bed once and for all!

O.B. · Sep 10, 2012

Finally got time to put the head studs in. Watch for the washers when taking the head bolts out. Also used a little dab of trans jell to the ball. To hold it on the spring for the tensioner.

charlie99 · Sep 11, 2012

O.B. said:
Finally got time to put the head studs in. Watch for the washers when taking the head bolts out. Also used a little dab of trans jell to the ball. To hold it on the spring for the tensioner.

How did you like taking the tensioner out with the jackshaft right there.

10003514 · Sep 13, 2012

There are definitely easier ways to get the turbo in and out. One way is to convert all of the studs on the turbo to bolts. This gives much needed clearance to get the turbo in and out without taking everything apart.[/QUOTE]

I'd like to replace all the studs from header to turbo and also exhaust to turbo when I reinstall my BC kit. What size and grade of bolt have you been using?

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