Boost control options for the new billet turbos.....

[Blazer406]

Mainly referring to 67mm... but others with other billet turbos can chime in as well.....

I read alot of the people here are having boost control issues with the stock style internal wastegate..... got boost creep..... among other issues..... some have managed to port their wastegate hole out large enough and managed with some success.

What setup do you have and how much boost have you gone to?

- stock internal wastegate?

- modified internal wastegate? -if so what mods? i.e. how big did you go on the hole... and what WG actuator are you using?

-external WG actuator.... what brand and size? How do you like it?

What boost controller are you using?

 

[Bent6]

Billet 6765dbb with the hole ported to the max - I originally tried it with an ATR 3" dp with external TiAL 38mm gate but it would overrun the gate. Instead of fighting with it, I just went to a TiAL 44mm gate off the header dumping back into a 3.5" DP - problem solved. AMS 500 boost control used on both wastegate configurations.

The new billet turbos flow a TON of air. I seriously doubt a stock style gate will be able to control one of these turbos. I believe Jay C tried one with the stock puck style gate fixed wide open and the boost would still go out of control.

Here's my current setup ......................

 

[Blazer406]

Will...your setup truly looks amazing. I have been contemplating for some time to step up to a 3-1/2" DP..... now that I am looking at a 67 billet turbo..... I am thinking about the DP upgrade at the same time.... and going to the external gate....it is just alot of $$ at one time.......I guess I could convert my current 3" SS THDP to an external gate.....similar conversion that you have done.....

Again.... great job Will. You going to Reynolds?

 

[Bent6]

Thanks for the compliments.

Although it's more trouble to fab, I think this is the best wastegate configuration for ANY turbo unless you just want to maintain the stock look. The problem with the new billet turbos is that they spool so fast and move so much air they will overrun a marginal WG setup. This configuration bleeds off exhaust before it ever enters the turbine housing. I can control boost as low as I want - even down to 5# with this setup. Also, this give me room to grow - may step it up to a 71mm billet down the road.

Not going to Reynolds - too far and too many work commitments right now.

 

[JayC]

Will...your setup truly looks amazing. I have been contemplating for some time to step up to a 3-1/2" DP..... now that I am looking at a 67 billet turbo..... I am thinking about the DP upgrade at the same time.... and going to the external gate....it is just alot of $$ at one time.......I guess I could convert my current 3" SS THDP to an external gate.....similar conversion that you have done.....

Again.... great job Will. You going to Reynolds?

TurboSmart 50 and a 3.5 inch DP. We can hook you up

 

[V6RACER]

What we noticed on a local car is that a 38mm ext gate and a 67 still has some boost creep. If you want to control creep you need a larger wastegate and plumb it as Will has it. I have done a very similar setup in some local cars.

 

[GNBRETT]

6765, 3.5 DP, Tial 44 mm, AMS 1000.

 

[Darkcyde]

6765, 3.5 DP, Tial 44 mm, AMS 1000.

i hate you! lol jk'ing buick love!

Apexi AVCR is my boost controller of choice, haven't run it on my t66dbb, 3.5dp, internal gate yet.

 

[Rell87]

I want a billet turbo:frown:

 

[Blazer406]

That's all great...... but you just took an $1900 purchase and turned it into at least $3k. That is alot of change to drop on a "turbo upgrade".

Why couldn't I have just been born a millionaire?

 

[Blazer406]

What about modifying the WG puck.... like a larger diameter round one.... or maybe even an oval one? ... dunno how big you could go... it wouldn't take a whole lot bigger to yield a substantial increase in CFM through the hole.....

I don't want to overthink this... but it could affect the max boost (make it lower) because the WG spring was trying to hold a larger surface area shut... due to the larger hole and larger puck.....

 

[Dean]

What about modifying the WG puck...

I don't want to overthink this... but it could affect the max boost (make it lower) because the WG spring was trying to hold a larger surface area shut... due to the larger hole and larger puck.....

This can be done will good results for lower CFM turbos, but from what I have been reading, you get in these larger turbos and you will have issues.

I have an PTE52 (60 series, basically) with a 1.3" puck ported stock elbow and ATR 2.5" DP, the one that they would sell with their headers way back when. The hole is 1.15" as I recall. I run this setup because I like the stock "sleeper" look and doubt I'll ever change. As long as the WGDC % isn't doing any major scaling at the 2-3 shift, I'm good for controlling boost levels wherever I want, and my typical street setting is ~27-28psi in 1-2 when I have good 100 unleaded available. Most of my driving is street, and I like it lively, but I have to turn it down when I'm going to the track as the scaling into 3rd is just 5%, and that psi would detonate the poo outta my engine.

It took a LOT of porting and modifying of the elbow AND exhaust housing, though. To get a good seal on the exhaust housing, metal was built up on the outer edge and then the housing mating surface was machined flat. This gave me more working room to unshroud the puck. Lots of grinding occurred on the exhaust housing, cleaning up the pathways and minimizing short side radius'. I joke about more iron being on the floor than on the turbo assembly by the time I was done.

Awful lot of work to remain somewhat stock appearing, and I believe it is pretty much maxed out as far as what it can control, and that's not a lot. I have been dreaming of the BB6765S as an upgrade, but I highly doubt the boost would be controlled very well. I'm now pondering a 6265. Not so much for a maximum power increase, but for drive ability and lower end power.

 

[JayC]

What about modifying the WG puck.... like a larger diameter round one.... or maybe even an oval one? ... dunno how big you could go... it wouldn't take a whole lot bigger to yield a substantial increase in CFM through the hole.....

I don't want to overthink this... but it could affect the max boost (make it lower) because the WG spring was trying to hold a larger surface area shut... due to the larger hole and larger puck.....

You cant go but so big and the exhaust doesnt like making that turn there.

We finished a downpipe for a customer yesterday with a 50mm TurboSmart gate on it. With no sort of boost control, the wastegate kept the boost level at 5.7 PSI on its own with a 5 PSI spring.

You cant get much better than that. External gates OFF THE HEADER are where its at. Trying to cram exhaust gas through that hole in the turbo housing is a waste of time.

 

[Quik Six]

Has anybody tried the 3.5" downpipe with external WG that Mike Licht is selling? I'm not familiar with external WG but the internal one is not getting the job done and I've got an oversized puck with 3.5" THDP. I plan on taking one more shot at porting and contouring the hole but I'm beginning to believe Jay is right about the billet turbos.

 

[WSLN 6]

Jay set me up with the 3.5"/50mm combo and it works great. Just need to get another 7psi spring in there to find a happy medium....

 

[JayC]

Has anybody tried the 3.5" downpipe with external WG that Mike Licht is selling? I'm not familiar with external WG but the internal one is not getting the job done and I've got an oversized puck with 3.5" THDP. I plan on taking one more shot at porting and contouring the hole but I'm beginning to believe Jay is right about the billet turbos.

The problem isnt the wastegate, its the hole in the turbo housing youre trying to cram the air through. Its a straight 90 degrees, its a smallish hole and the air just doesnt want go through it. Putting the gate off the header gives the air a smoother transition into the wastegate tube and you can use a much large tube for better control. The TurboSmart 50 gate uses a 2 inch feed.

Precision's new gate drops the price of our downpipe combo to about $1050.. yea, its expensive but its handmade in the US with a quality gate. Fried rice versus fillet mignon.

 

[Dean]

The problem isnt the wastegate, its the hole in the turbo housing youre trying to cram the air through. Its a straight 90 degrees, its a smallish hole and the air just doesnt want go through it.

I agree. Some day I'll take apart my junk and get some pics of the grinding done to the PTE housing.

 

[DailyDrifter]

Fried rice versus fillet mignon.

Now I want some chinese food...............thanks Jay:biggrin:

Jay does bring up some logical points. External gates are the way to go if you want to have rock solid boost. No sense on putting a band-aid over a bullet wound (yeah, I got analogy's too)

 

[John Wilde]

The problem isnt the wastegate, its the hole in the turbo housing youre trying to cram the air through. Its a straight 90 degrees, its a smallish hole and the air just doesnt want go through it. Putting the gate off the header gives the air a smoother transition into the wastegate tube and you can use a much large tube for better control. The TurboSmart 50 gate uses a 2 inch feed.

Precision's new gate drops the price of our downpipe combo to about $1050.. yea, its expensive but its handmade in the US with a quality gate. Fried rice versus fillet mignon.

Thinking outside the box, would a Turbonetics style turbine housing potentially work better to control the boost?
If so it might be worth asking Patrick and Harry about.

 

[bison]

Thinking outside the box, would a Turbonetics style turbine housing potentially work better to control the boost?
If so it might be worth asking Patrick and Harry about.

If these guys are spending that much on putting an external on then they should just build around a tangential 4 bolt. 3 bolt housings suck on cars making over 650hp. Anyone who spends $2-3K on a turbo install and the car runs slower than very low 10's is crazy. The $ could be spent elsewhere and net more gain.