user_name

And by no wastegates I mean:



It results in this:



I get 17psi after boost creep with the tial 38mm wastegate in place after boost creep. I figured this would answer lots of questions I had about how to fix this issue. The tube for the WG is about 38mm, and the housings are port matched. I don't really think there is enough room to fix the issue by putting a 44mm flange on this downpipe flange.

This is after putting a XS power 2.5" catback onto my 3" X pipe. I could really use some more boost control, and this design flaw is just not making that possible.

Any suggestions? TTI's only suggestion seemed to be not running low boost. I can only fit so much tire on this thing.

BLOWNBLUEZ06

I wonder if you can grab another place before the turbo and weld another flange on it and have a secondary wastegate

user_name

I think it would have to be off the actual housing. The flange doesn't have enough room I don't think. Rather than buy more wastegates I'm thinking we are going to have to put a flange at the bottom of the housing so it's a straight shot to the hole. Weld the old one up.

Turbo-Geist

Joe, this was a great idea. I feel that you have just single-handedly answered the question about whether or not the 5-bolt flange and wastegate combination is up to the task of controlling large amounts of exhaust flow. I know that this topic has been talked about off and on many times here. I never would have imagined that you could remove the wastegates and still make 12 psi.

The exhaust is following the path of least resistance and that is to continue through the housing and out the downpipe. I'm not sure yet how to calculate how much is being bypassed out the wg exit port, but it's way less than I would have imagined with the current design.

SBCGENII

Awesome.

I was just looking this up the other day. There are a couple of threads on the bullet about this. You might find a housing cast with a wastgate flange that will work for your turbo with the use of a flange adapter. I was just searching for flange adapters and they make them for everything. I think a wastegate in the right spot and angle in the ex housing would be the most effective way to control boost. Just a matter of will it crack or not.
http://www.yellowbullet.com/forum/sh....php?p=4950359

JDS99

I don't have a ttix kit, but same size 6265 turbos with same placement. Having the wastegates BEFORE the T3 flange off of the manifold, and I was able to control boost out of my 402ci to 5.xpsi. That was with 3" exhaust all the way out and only a couple Kooks race bullets for mufflers. Didn't try to go any lower, and that was with the same tial 38's. Depending on how I had the vacuum line run, saw anywhere from 5psi to 20+psi and no boost creep. I doubt you want to modify your ttix manifolds, but just food for thought.

If you do want to modify some turbine housings, I have a pair of t3 .82 a/r f1-65 housings with 5-bolt discharge i'll make you a good deal on. Had them on for 300mi or so

user_name

You've gotta install these things to appreciate just how little room you have to work with here. Good ideas.

I think I'm about to order parts. I'm going to put 44's on here just b/c we are only doing this once. We're going to cut into the bottom of these housings, weld a vband flange, and then run tubing to the new gates. Old WG hole will be welded up.

The goal here is to get boost control down to about 10psi WITH straight 3" exhaust. No mufflers. Adding mufflers dropped about 5psi off the "low boost" setting, but it introduced some lag that is a real bitch if I have to short shift or pedal the car for traction. That happens a good bit when low boost is 800rwhp.

5 Liter Eater

Why plug up the old WG? Why not run quad WG's? Although I'm pretty sure bigger WG's welded to the housing should do the trick.

JMBLOWNWS6

Put car on kill and party time!

user_name

Only so much room in there 5 liter eater. Shouldn't be necessary. Entire problem is just WG placement imo.

On a 28" DR on the street it can't always put down 800rwhp from a 60 with a sharp ramp rate. Can't even bring in the extra 150rwhp until a few seconds in. I want to a 12-24psi range. Anything less is just ******** IMO. I intended to do this build right, and I went the wrong direction with this kit.

JDS99

Instead of buying more gates, or using 4 gates, etc.. You are already committing to cut and weld a v-band flange to the existing housings on the bottom, so what about adding that with a pipe turned and merged to the pre-wg pipe? Essentially adding a second feed to the current wastegate/placement.

joshtownsend

I checked my A and a bracket.... i never had a single issue with this..sorry.. hahaha

Chris Stewart

I was talking with George at TTi the other day. They just did a build with a C6Z stock motor, and Precision billet wheels like you got. It made too much boost for a stock motor. So he added a 3rd WG on the intercooler and was able to control it for low boost. I haven't seen it, but you might wanna check what they did.

user_name

I'm thinking you are referring to the maybe a BOV used to bleed boost? WG would need to be after the exhaust valve, before the turbine wheel, and distributed somewhat equally on each side. I've heard of doing what you are saying.

I'm not planning on checking in with them. They had the chance to stand behind the product when I first purchased, but they claimed "Timing is too low with rich AFR causing boost creep", then "you must have mufflers with this kit", and finally "who really wants low boost anyway?" I had to tear apart the car multiple times after this issue. I certainly could have experimented had I been sent parts.

JDS99, I also thought about tying them together, but speaking to anybody who has designed and built these from scratch you'll be told the 90* wg port is the only issue here. It's a big no-no. You get away with it on some setups. Cars with bigger turbos are running less boost with similar parts. Just doesn't make sense to clutter things up more.

Chris Stewart

He definitely said he added a WG on the IC. Sounds like it worked to dial down those monster turbos to 7psi.

SBCGENII

He should just take a knife to the couplers that will leak the boost off for free!

inspector12

I was going to suggest the same thing about a WG on the IC like the guys with SC have done for having multiple boost setting with the same pulley combination etc... Its got to be way cheaper than what your about to do IMO. But its your car Joe and you always figure it out in time so what ever you decide and go with I'm sure you will make work. But I would think 12lbs should be low enough to hook it with a little timing pullled in the ramp etc... GL!

chuntington101

I see a few turbo rebuilds in the future if you are bleeding boost post turbo! if the gates cant hold the turbos back they will over-spin and that will put much greater wear on the turbos.

user_name

Yea, I'm just after the proper way to fix it with the amount of room I've got. It would be great if there was just a different housing I could use, but I don't see any. I didn't like the fact I had to run restrictive exhaust and introduce lag just to get it below 21psi. We are going to fix it for good.

Should have just had a custom kit fabbed from the start is what I take from it all. Live and learn. I didn't know much about turbos in general going into this.

JDS99

I did everything on my setup except for the base manifolds (bought project from another guy). I ended up modifying the manifolds to add the wastegate placement to before the T3 flange instead of utilizing the port on the 5-bolt housing. I certainly agree the wastegate placement on the TTix kits is junk. What you'll also notice on any of the builds from scratch or real custom kits is that the wastegate is plumbed from pre-turbo flange. Flow velocity once the exhaust is in the turbine housing is just too high to be redirected the way the 5-bolt housings try to.

That being said, the manifolds on mine.. THE ONLY THING I DIDN'T MAKE, cracked after ~300miles. So, now i'm making my own which is what I should have done from the beginning anyway. Wastegate will be plumbed pre turbo flange, like last time, and don't expect to have any boost control issues since there weren't before. Also running primaries so that I have a ton of room up front for larger compressors down the road.

While in there, ditching the 5-bolt housings in place of .85 a/r 3" v-band... Which 68mm turbines would fit in , hmmm.

Attached a few photos for reference.

Completely agree. If the wastegate setup is only capable of controlling pressure to a certain amount, then bleeding cold side pressure is just going to make the turbos continue to spin up. Actually kind of surprised that the TTix guys are doing this...