Terry Houston style dp pics

[turbowrenchhead]

More Terry Houston style pics

Now it has to get planed for a nice flat surface.

 

[Jim Puehl]

Has anyone done some back-to-back strip testing of this set-up? Or maybe some dyno-pulls for comparision? What's the purpose of this set-up? I'm sure for the $160 investment, there must be some sort of gain. I might be interested in trying this on a 301T.

 

[turbowrenchhead]

I am possitive it will flow alot better the the stock elbow and down pipe. Have you taken a close look at the stock elbow lately?

 

[FJM568]

Looks good...Can't beat the price either...


Jim Puehl, the purpose is to cut down on a lot of the right angle factory bends in the stock DP setup...I forget what the percentage drop in flow is around a sharp 90* bend, but it is just horrible when you have about 6 of them before you even get to the catalytic converter...It decreases the flow and creates a helluva backpressure which affects how fast the turbo spools and creates more lag...

The factory DP is about 2" to 2 1/4" and even less than that when you get into the 90* bends because they used muffler shop bends which crimps the pipe smaller at the corners...By using mandrel bent tubing and a larger diameter tubing as well, it creates less back pressure and the airflow has less pressure loss around the mandrel bends than the stock DP, which makes the turbo spool faster and people have actually noticed an increase in boost with no other changes elsewhere...

Anything you can do to make the turbo motors breathe easier, whether it's on the intake side, or exhaust side is going to help tremendously...Naturally aspirated(NA) motors need some backpressure on the exhaust side to help scavenge the cylinders, but turbo motors don't need backpressure, because the incoming air charge under boost pushes whatever exhaust is left in the cylinder, so as I've said, any way you can make the motor breathe easier will help your turbo motor a bunch...

Hope that explains it okay...

 

[Jim Puehl]

Jim F

Right now, I have a 2 9/16" DP with 2 mandrel bent 90* bends which dump out right behind my front tire. The 2 9/16" pipe has the same OD as the metal ring on the "donut" that fits on the outlet side of the elbow, eliminating the donut. Do you think the "Terry Houston" style DP will benefit my setup?

Thanks for the reply.

 

[FJM568]

What motor do you have??? Are you talking about the Firebird??? Running the Pontiac motor or a Buick V6???

If this is the Pontiac motor, I'm not really sure because I can't recall seeing how the DP/wastegate setup is designed... But basically, if you already have a mandrel bent DP setup, depending on how it is connected to the turbo would dictate flow and backpressure in the system...

If you could post a link to a pic of what the turbo/DP/wastegate setup is, then I could probably "guess"

Nice car, btw...

 

[turbowrenchhead]

I don't have enough experience on this subject to answer your question. I am sure someone has an opion though. I know it will benfit my setup.

 

[Jim Puehl]

Jim F,

I have some pictures of the turbo at www.geocities.com/jpuehl/photos/. I think image 18 best shows the turbo. I am talking about the '80 - '81 turbo Firebird with the 301 Pontiac engine. After looking at the turbo, I can see how this set-up may help as the "elbow" immediately turns the exhaust up and to the front, slightly. With this set-up, I could bring it straight out. I will just have to check with NHRA to find out if it is "legal" for the Stock class.

Another question I have about this set-up, though, is I have heard that you WANT some bends in your DP, some what close to the "elbow" because the exhaust coming out of the turbo is still "whirling" around and it could get "stuck" if the pipe was too straight. Does anyone know anything about this?

 

[FJM568]

A mandrel bent DP would probably help you out some...Your exhaust actually seems to come straight out of the turbo as opposed to how the Buick V6 turbo is designed on the 84/5s...As you have probably seen, the cast iron elbow on the turbo has a right angle flow path built into it to direct the exhaust flow forward, then the DP takes a right angle towards the pass side fender, then another right angle straight down towards the upper control arm, then another right angle straight back, then down, then back and so on...Your DP is actually not bad...If you could just make a new DP and use like 45 deg bends instead of 90 deg bends, it would work better...You have less flow loss using 2 45deg bends than using on 90deg bend...

I would come straight out of your turbo, use a 45 deg mandrel bent tube angled down and back, then another 45 deg tube angled down towards your exhaust pipe going to your mufflers...

Basically, just eliminate that sharp 90 deg bend you have there at the firewall, start angling downward after you exit the turbo...Other than the sharp downward 90 deg bend in your DP, it's really not that bad of a setup...

On that second question, I haven't heard that one before...

 

[cool 84]

All I have is a seat of the pants experience but I went from a stock elbow and 2.5" mandrel bent DP to a 3" DP that eliminated the elbow so the exhaust comes straight out of the turbo. I can say for sure the spool was better. I never got a chance to go WOT so I don't know about power but I suspect since the spool improved like it did there should be a decent power gain. I think getting rid of the elbow is just as important as the bigger pipe. Especially with my TE64 turbo, the outer 1/2" of the wheel was blocked by the stock elbow.

 

[Jim Puehl]

Jim F,

You're right, I did finally see some pix of the Buick turbo and now see that this set-up should to wanders. I was also thinking about getting rid of the 90* bends for some 45*'s. I put this DP together myself using a 2 9/16" "J" bend. I don't have an exhaust except for what you see in the pix, so I just need to get the pipe pointed down. I don't have the A/C - heater box, so I can do all most anything with the DP.

 

[turbowrenchhead]

I happend to see Boost231 ad soon. I picked up a 3" down pipe from zero to sixty performance. I think that will work very nice with the thdp sytle elbow.