3" downpipe for a stock turbo?

[topfuel]

Plans for this winter include a new downpipe, porting the stock
turbo and a big neck on the stock intercooler.
Don't know much about downpipes since I'm still using the
stocker, what are my options for a stock turbo?
Do I keep the stock exhaust elbow and port it, or will a good
downpipe eliminate the elbow all together?
Will I need an external wastegate if I lose the elbow?

I did a search but I'm still confused about my options
need some advice from the experienced...

Thanks
Mike

 

[JToups386]

I just don't think you can beat the Terry Houston 3" downpipe!
It eliminates the elbow all together, and has a huge wastegate puck to allow for opening up the hole in the turbo for better boost control. It fits remarkabley well too. I've never know anyone who has used one, that did not absolutely like it! It now comes in a stainless version for around $439-ish, and is probably the most widely used 3" downpipe on the market. I believe there's also a 3.5" version for the really hard hitters.
Most Turbo Buick specialist vendors sell it.

 

[turboman38]

I'm with JToups386. Get a 3 inch THD and eliminate the stock elbow.

 

[blackbuick87]

At your level a THDP would be a waste IMO. For the $500 you would spend on a pipe and dump, you could almost have a TE-44 or you could buy a used V4. Sure they look nice but it has been proven it makes almost no difference at the low 12's

 

[BEATAV8]

Mike,
You're near by, I'm in Lake in the Hills. There's a fab/engine shop near me (in Woodstock) that welded on my Duttweiler big neck for only $20, I recommend them in case you're interested. It's called Andresen Engine Development.

And Oh yeah, I definitely recommend the Terry Houston pipe. be sure to enlarge the wastegate hole in the turbine housing to take advantage of that big THDP puck. Definitely helps stabilize boost control when you're trying to run >22 PSI.

 

[topfuel]

Thanks guys...

Well, maybe I should try porting the elbow first before
dropping 500 bucks on something that may, or may not
show any gains at my level.
The THDP is obviously a nice piece and if I see a used one
for sale I may still get it anyway for future expansion.
Will a THDP for a stock turbo , fit a bigger turbo as well?
Lets say I smoke my stocker next year and upgrade to
a 44 or something, will the same DP bolt up ?

stevemon, that's huge mph for the stock stuff
Were you in the elevens on that combo?
I'm removing the a/c system to shed a few pounds
for next season, but dont want to mess with hood
swaps and paintwork right now.

MJRWOOD, sent you an e-mail.

 

[JToups386]

Yes, the THDP will work fine with a turbo upgrade. Some people have gone to the bigger 3.5" units, but, I cannot see a need for it unless you're running in a Top Fuel Dragster class...
All the air fromt the motor is passing through the exhaust housing on the turbo, and surely a nicely mandrel bent 3" pipe can easily accomodate it!
As for porting the stock elbow, we used to do that in the early 90's, when upgrades were almost non-existent. However, I had a friend who ported so hogwild, that it ended up blowing a hole in the elbow under boost, due to his overkilled port work. I still think it would be a worthwhile upgrade for you to get a better downpipe, but, I also agree that you'd do well to search for a used version online. Cheaper is the way to go!!! Hooker also makes a nice 2-3/4" pipe that I used on one of my TR's, and it worked fine too! There are several other versions out there too, and I think they're all adequate and are certainly better than stock.

 

[Roger]

When I installed the TH dp, I already had the 2.5" ATR cat back. I noticed a very big improvement above 70mph. The TR prior to the TH dp would pull very strong up to 70mph & then seem to lose some of its aggresiveness above 70mph. The TH 3" continues to pull hard up to 100+ ( end of 1/4 mile).
I still have the original stock turbo & only time the motor has ever been opened was to replace the timing chain.

 

[d0n_3d]

when i was stock and put a 3" DP o with a hi-flow cat i noticed MAJOR changes with my car...turbo spooled almost instantly...gutted cat and then it spooled instantly also could feel the power difference...not to mention the car had a loud turbo whistle sound i love it...now i have a te-44 turbo and the whole exhaust is straight flow and boy it sounds nice and the performance is there...

 

[Grumpy]

ahhh the ol "butt" dynos Personally I think its a waste of time on a stocker...maybe a 3" downpipe to the stock elbow...ya I know the elbow doesnt work eithier we have only gone 118-121 with it....guess if I changed we would be runnin 127-130

 

[national]

dont need it now!!

Dont waste your time or your money at this stage..I put a THDP on mine & it slowed down..
Brian

 

[Brian Mc]

Now i don't get this... how can taking a exhaust restriction away slow a car down? maybe the fuel curve is thrown off by the extra exhaust flow

 

[Brian Mc]

Oh yeah i have a 3" THDP I love it