Surging?

turbojimmy · Tweet this Post! #1 (**permalink**) 01-16-2008, 12:26 PM

I have a T70 turbo bolted to my Buick?s 3.8L engine. I have stock (but heavily ported) heads and intake. It?s an older T70, I?m not sure of all of the specs. It has a Precision exhaust housing on it, too. I?m getting a ?flutter? under acceleration (like ? throttle). It?s the same ?flutter? as if I let the throttle slam shut. If I open or close the throttle some more it stops. At WOT it?s fine. I?ve come to understand that this is referred to as ?surging? and that newer compressor housing have anti-surge porting to help this problem. Is my fix as easy as getting a new housing? Or do I have a bigger problem in a mis-match to my application? Does the surging hurt the turbo?

Thanks,
Jim

Robert · Tweet this Post! #2 (**permalink**) 01-16-2008, 06:31 PM

Quote:

Originally Posted by turbojimmy

I have a T70 turbo bolted to my Buick?s 3.8L engine. I have stock (but heavily ported) heads and intake. It?s an older T70, I?m not sure of all of the specs. It has a Precision exhaust housing on it, too. I?m getting a ?flutter? under acceleration (like ? throttle). It?s the same ?flutter? as if I let the throttle slam shut. If I open or close the throttle some more it stops. At WOT it?s fine. I?ve come to understand that this is referred to as ?surging? and that newer compressor housing have anti-surge porting to help this problem. Is my fix as easy as getting a new housing? Or do I have a bigger problem in a mis-match to my application? Does the surging hurt the turbo?

Thanks,
Jim

First things first do you have a bypass/blow off valve?

turbojimmy · Tweet this Post! #3 (**permalink**) 01-17-2008, 06:13 AM

Quote:

Originally Posted by Robert

First things first do you have a bypass/blow off valve?

I do not have a bypass/blow-off valve. I've actually posted a question about this on the Turbobuick boards and got mixed opinions as to whether the BOV would be of any value in this situation. I'm leaning toward getting one anyway for the closed-throttle scenario. If it addresses the part throttle surge that's all the better.

Thanks,
Jim

Robert · Tweet this Post! #4 (**permalink**) 01-17-2008, 09:01 AM

Quote:

Originally Posted by turbojimmy

Quote:

Originally Posted by Robert

First things first do you have a bypass/blow off valve?

I do not have a bypass/blow-off valve. I've actually posted a question about this on the Turbobuick boards and got mixed opinions as to whether the BOV would be of any value in this situation. I'm leaning toward getting one anyway for the closed-throttle scenario. If it addresses the part throttle surge that's all the better.

Thanks,
Jim

I don't know if it would eliminate part throttle surge. For that you may need some surge porting on the compressor to allow the air to bypass the inducer and go straight to the major depending on your compressor size, map, and efficieny as it relates to your motor. For closed throttle surge there is no doubt in my mind a bypass valve will help.

turbojimmy · Tweet this Post! #5 (**permalink**) 01-17-2008, 10:40 AM

Quote:

Originally Posted by Robert

I don't know if it would eliminate part throttle surge. For that you may need some surge porting on the compressor to allow the air to bypass the inducer and go straight to the major depending on your compressor size, map, and efficieny as it relates to your motor. For closed throttle surge there is no doubt in my mind a bypass valve will help.

So who could help me with that sort of analysis? Do I contact Turbonetics directly? Or a Turbonnetics distributor? I got it used so I'm not really sure where to go with it.

Thanks,
Jim

phoneguy · Tweet this Post! #6 (**permalink**) 01-23-2008, 11:01 PM

Quote:

Originally Posted by turbojimmy

Quote:

Originally Posted by Robert

I don't know if it would eliminate part throttle surge. For that you may need some surge porting on the compressor to allow the air to bypass the inducer and go straight to the major depending on your compressor size, map, and efficieny as it relates to your motor. For closed throttle surge there is no doubt in my mind a bypass valve will help.

So who could help me with that sort of analysis? Do I contact Turbonetics directly? Or a Turbonnetics distributor? I got it used so I'm not really sure where to go with it.

Thanks,
Jim

Jim, Call Jack Cotton He can set you in the right direction. If you need his number 413-789-0531, Tell him Bryan in St Louis sent you.

turbojimmy · Tweet this Post! #7 (**permalink**) 01-24-2008, 02:58 AM

Quote:

Originally Posted by phoneguy

Jim, Call Jack Cotton He can set you in the right direction. If you need his number 413-789-0531, Tell him Bryan in St Louis sent you.

Actually I did call him. He had helped me out with the waste gate bracketry on it. He thinks I can get an anti-surge ported housing but doesn't think a GT-K housing will fit on the T70. I'm waiting on a price for a new compressor housing.

I might just live with it, too. I dunno yet. My Godzilla BOV arrived earlier in the week. It's nice. I need to find someone who can/will weld the flange to my aluminum up-pipe.

Jim

phoneguy · Tweet this Post! #8 (**permalink**) 01-24-2008, 10:25 PM

Jim, you should have sent your pipe to Jack and let his son weld the flange . I am having Jack do a setup for me right now for a Godzilla vented back to the cold air kit.
I just received a GT-K 850 yesterday. It arrived with the wrong AR but I am going to see how it works. My paperwork shows what I ordered but that is not what was sent. Turbonetics was no help, referring me back to Jack....LAME ( Jack didn't order it wrong.. they built it wrong). This is the second wrong turbo in two weeks. I made it very clear that I needed my turbo by Dec 13th due to my car going in for paint. Needless to say my car still hasn't made it to the paint shop and I am not very happy . I hope I don't need to send my turbo in for repair ever again.

turbojimmy · Tweet this Post! #9 (**permalink**) 01-27-2008, 01:57 PM

Okay - I finally finished up the Godzilla installation. It does cure the part-throttle surging because it is bleeding boost away at part-throttle. I think I'm okay with this because it slams shut instantly when I open it up. Either that or I need to tighten up the spring and/or remove the boost feed from the BOV. I think the boost in the up-pipe is overpowering the valve at part throttle. You can hear it bleeding boost at around 5 PSI in the vids below. I've also attached some pics. So far I really like it. It's nice not to have that awful sneeze/flutter sound all the time.

Vids:
http://www.youtube.com/v/CdrViA9i0yc
http://www.youtube.com/v/CHZhjrEwgd8

From underneath:

From up top:

Jim

phoneguy · Tweet this Post! #10 (**permalink**) 01-27-2008, 10:30 PM

Nice Jim. I need to get mine now.
More bad news on my end. I got my new GT-K 850 installed today... its pumping oil out of the exhaust like you would not believe. It ran for about 6 minutes and smoked out my street from inside of my garage. I didn't even get to drive it!!!! I wonder how long it will take to get another one this time???? I am not a happy camper. Jack cotton has already gotten an IM and will call me in the morning. GRRRRRRRRRRRRRRRR.
Turbonetics feel free to chime in here. Brian in sales knows the turbo in question. I have sent him IM's in the last two weeks and I get no response.
Somebody needs to get this fixed NOW!!!!!
Bryan