Need help

[Pete Revenidis]

I remember my brother in law having to port the waste gate in hi GN back in the 90'sday he had same problem is there a post on here on how to do it with pictures

 

[mgmshar]

Couple of points here...

1. Earl is correct in one thing - if you had a freer flowing exhaust system, you wouldn't be corking-up your turbo, and your boost would be the same whether you had the dump open or not. With that being the case, you could run the stock boost control system, and it would be OK. When I first installed my ATR 2.5" duals, I still had the stock boost control system. Because the ATR system flowed well, the boost remained the same whether I had the dump open or not. Where I disagree with others is I don't think it's a waste of money to spend $50 (about what I spent) to get a check valve type controller on there to make sure your boost is rock steady. Not to mention that you already said that you can't get boost below 21 psi with the dump open, which probably means you have a HD actuator, which means installing a freer flowing exhaust is going to cause you to run 21 psi all the time if you keep the stock boost control system (unless you get your chip re-burned to run the stock boost control at a lower duty cycle, which will cost you more than 50 bucks...).

2. I had to port the wastegate hole on my TA-49 after I installed the ATR exhaust system and front-mount intercooler. I had the infamous "boost creep" issue where boost would increase as RPM's increased. I tried burning custom chips to use the stock boost control to get around it, but it never worked out well. There are posts in the Turbo section (I think) that show details of how to do it. If the search function on this board is working, try searching for it ("how to port wastegate"). If you're planning to install freer flowing exhaust and intake related stuff, you will likely need to port your wastegate.

3. "Tin-Man CAI" is a cold-air induction kit produced by the "Tin Man" on this board. They are sold by several Buick vendors, example link below. There are other nice CAI kits out there as well. I am partial to "Tin Man's", because he's a personal friend of mine, and honestly they work really well. http://www.gbodyparts.com/product_info.php?products_id=978

4. "CAS V-2" is a front-mounted intercooler (FMIC) that was produced by Charged Air Systems (owned by Tony Dequick). They went out of business many years ago, so these intercoolers are hard to find. Several vendors make nice FMIC's for our cars nowadays. Honestly, you shouldn't even think about this upgrade until you've got the boost, exhaust, injectors, etc. figured out and running steady first. People who change to FMIC's, which sit in front of the radiator and A/C condenser, usually also have to upgrade the cooling fans and/or radiator to keep the car running cool, since the FMIC blocks air flow to the radiator. You don't need a FMIC to run 11's with your combo, but it might make it easier to get there.

 

[TurboBuRick]

The wastegate dumps into the same pipe as the exhausts that passes through the turbine. If the (restriction) theory is correct the wastegate should flow better when uncorked as well. Some things don't add up....

 

[aminga]

It may be a HD actuator that runs at a nimimum of 18 PSI. A stock one should allow you to turn it down to 12

Good Point

 

[mgmshar]

The wastegate dumps into the same pipe as the exhausts that passes through the turbine. If the (restriction) theory is correct the wastegate should flow better when uncorked as well. Some things don't add up....

All I can say to this is that I switched from the stock downpipe, test pipe, and exhaust (including stock muffler) to the 3" THDP, test pipe, and ATR 2.5" exhaust back when I was running the stock boost control. When I got done, my boost went up several psi with no other changes, even though both the turbine and the wastegate were both "flowing better". Others have had similar experiences when using the stock boost control and doing something the lowered back pressure behind the turbo. Since the OP is essentially doing the same thing (significantly lowering back pressure behind the turbo when he opens his dump), and he is running a similar turbo (TE44 vs. my TA49), I'm not surprised he's getting a similar increase in boost. Admittedly, going from 15 psi to 21 psi is more than I would have expected. But, the only thing he is changing is the exhaust system behind the turbo, so what else could cause the boost to change when he opens his dump? Maybe I'm dumb, but I can't think of anything obvious.

Come to think of it, I was running an un-ported wastegate when I had the stock exhaust system. When I put the freer-flowing stuff on, I had bad boost creep that I could not fix by changing the stock wastegate duty cycle % in the chip (I burn my own chips). I had to port the wastegate hole to keep boost steady at around 17 psi as RPM's went up. This makes me think that freer flowing exhaust "helps" the turbine flow much more than helping the wastegate flow, for whatever reason.

 

[earlbrown]

Yes they dump into the same pipe much the wastegate hole is much much smaller than the exhaust wheel's hole. Plus even when the wastegate puck is wide open there's still a large disk hovering over the hole.

When a corked up exhaust is installed it's choking both passages. When the exhaust wheel gets chocked, it turns slower. At the same time when you choke the smaller wastegate passage it causes the wheel to spin faster. Since it's so small the net result is still at an underspeed situation.

When you uncork it, the exhaust wheel starts spinning like hell... Yes the wastgate hole can vent more.... but it can't vent enough to bring the shaft speed under control.


The only way to know what wastegate you have AND if you have boost creep issues is to run a single brand new hose directly from the compressor housing to the wastegate and see what the boost is. If your boost drops to 12 you have a stock duty wastegate and a signal leak somewhere in all your hi tech controllers (that cause loss of control). If it's around 17 you have a HD wastegate installed on the turbo and you don't need any fancy controllers to run on a non-alcohol street car because 17 is pushing the limits.

 

[earlbrown]

I remember my brother in law having to port the waste gate in hi GN back in the 90'sday he had same problem is there a post on here on how to do it with pictures

All you do is put a layer of grease on the wastegate puck and reinstall the elbow or DP. Swing the gate closed and make an imprint on the exhaust housing. Carefully remove the elbow and port to match leaving enough metal to maintain a seal when closed.
You'll often find they puck and the hole are non-concentric.

It never hurts to radius and smooth the inside transition but leave the outside square and sharp.

 

[Pete Revenidis]

All I can say to this is that I switched from the stock downpipe, test pipe, and exhaust (including stock muffler) to the 3" THDP, test pipe, and ATR 2.5" exhaust back when I was running the stock boost control. When I got done, my boost went up several psi with no other changes, even though both the turbine and the wastegate were both "flowing better". Others have had similar experiences when using the stock boost control and doing something the lowered back pressure behind the turbo. Since the OP is essentially doing the same thing (significantly lowering back pressure behind the turbo when he opens his dump), and he is running a similar turbo (TE44 vs. my TA49), I'm not surprised he's getting a similar increase in boost. Admittedly, going from 15 psi to 21 psi is more than I would have expected. But, the only thing he is changing is the exhaust system behind the turbo, so what else could cause the boost to change when he opens his dump? Maybe I'm dumb, but I can't think of anything obvious.

Come to think of it, I was running an un-ported wastegate when I had the stock exhaust system. When I put the freer-flowing stuff on, I had bad boost creep that I could not fix by changing the stock wastegate duty cycle % in the chip (I burn my own chips). I had to port the wastegate hole to keep boost steady at around 17 psi as RPM's went up. This makes me think that freer flowing exhaust "helps" the turbine flow much more than helping the wastegate flow, for whatever reason.

I think it has to do with a couple of factors We built 2 turbo BMWs and run external wastegates one car puts 490 to the wheels and the other 670 we dont have any issues with the boost but we also built the exhaust systems ourselves with Magnaflows and no dumps. Im just not that familiar with the system on the Buick. I will go over the hole car this weekend and see what I come up with. Mike do you sell your chips ????

 

[mgmshar]

No, just dabble in them. Hit up TurboBob (Bob Bailey) or Eric Marshall (TurboTweak) on this board. They are the chip masters right now.

I usually start with one of Bob Bailey's chips and customize it for my preferences. He's always very helpful and knows his stuff.

Posted from the TurboBuick.Com mobile app