BOV at part throttle?

[turbojimmy]

Greetings all......

MY turbo puts out way more air than the engine can use. Before I moved to this T70, I would only get 'the flutter' when I closed the throttle, which is fine. But now when trying to accelerate at a hard, steady pace at like half throttle there's more air hitting the throttle plate than can go through and it flutters. I can't accelerate smoothly unless I go WOT or really light. It makes all kinds of fluttering sounds and the boost gauge jumps all over the place. It gets a lot of attention, but I think probably because it sounds bad. Would a BOV solve this problem even at part throttle? I would imagine it would since it's acting on the difference in pressure between the intake and the pressurized side of the turbo? Is there any other way to address this (other than a smaller turbo)?

Thanks,
Jim

 

[Black Power]

I wonder if a bigger throttle body or upper plenum would help

 

[GNVYUS 1]

A BOV won't help because you are still in the throttle and it is seeing pressure to keep the valve closed.

What will work for compressor surge is putting a Tornado into your inlet track. I have 2 turbo cars with it ( GN and Talon ) and both no longer surge and I can hold any psi for as long as I want. Wish I can take credit for the find but Bruce Plecan figured it out first.

And watch the MPG and HP soar through the roof while using it, ok, just playin there.

 

[Jack Armstrong]

Wish I can take credit for the find

but Bruce Plecan figured it out first.

Bruce Plecan deserves honor & credit
for many finds and many
improvements from his innovative thinking.

Bruce contributed far more than any 6 of
the self-aggrandizing "TR-Gurus", and did it
from his modest shop, meager resources,
in declining health, needing supplemental O2.

Yet, Bruce was pounded on relentlessly
for years for challenging the "set way",
for even daring to think outside of the
self-perpetuating box of mob-think, i.e.,
the "One-Way Joses" & the Flat-Earthers.

Only in the last year of his life did it even begin
to dawn on more people that Bruce had been on
the right track(s) all along. And, from his constant
quest for data, tests & trials, had helped speed the
evolution of TR-thinking and modding ahead
by essentially 20 years... with no profit in mind.

Bruce's rewards came from thinking, persevering,
overcoming and sharing...and trying the "next" idea.

It has long been said that a prophet receives
no honor in his own hometown and that
the most effective genius has no ego.

Both were certainly true about Bruce Plecan. (R.I.P.)

 

[BARTGN]

Bruce Pelcan

What is/was Bruce Pelcan,s screen name? Would be interested to learn more about use of Tornado in inlet tract. Where in tract is TORNADO placed.

 

[ChavoLC2]

Turbo Surge Fixed , Thanks Bruce PLecan

Bruce Plecan deserves honor & credit
for many finds and many
improvements from his innovative thinking.

Bruce contributed far more than any 6 of
the self-aggrandizing "TR-Gurus", and did it
from his modest shop, meager resources,
in declining health, needing supplemental O2.

Yet, Bruce was pounded on relentlessly
for years for challenging the "set way",
for even daring to think outside of the
self-perpetuating box of mob-think, i.e.,
the "One-Way Joses" & the Flat-Earthers.

Only in the last year of his life did it even begin
to dawn on more people that Bruce had been on
the right track(s) all along. And, from his constant
quest for data, tests & trials, had helped speed the
evolution of TR-thinking and modding ahead
by essentially 20 years... with no profit in mind.

Bruce's rewards came from thinking, persevering,
overcoming and sharing...and trying the "next" idea.

It has long been said that a prophet receives
no honor in his own hometown and that
the most effective genius has no ego.

Both were certainly true about Bruce Plecan. (R.I.P.)

Upon reading all about surge on this site no one seemed to have a solid answer. It was an inherent anomalie some got and some didn't when upgrading to a larger turbo. All who experienced it know It's was a bummer driving like that. Nothin in between. Yeah at WOT didn't have any problems, but part throttle was terrible the car shook and shimmied, boost gauge went wild, flutter sputter surge, alky offf and on. The talk of BOV's to help cure the problem, will a BOV even help surge don't see how it would know exactly how much pressurized air to vent out and yet still allow decent boost build up, yeah I could see a BOV helping at the top end or where you just flat get out the throttle abruptly and need to vent that extra boosted compressed air that has no where to go once the throttle blade closed.

Upon sending DRBOOSTER a PM about placement went out and bought a ki-75 (75mm. or 3")Tornado took a couple minutes to install, fit perfect in the 3" intake hose and butted right up to turbo inlet. Went out and thrashed the car no compressor surge WHATSOEVER, nuthin, natha, zero, zilch, it was a PLEASURE again to lay into it with out it breaking up. So if your a non Believer and have severe surge and can't get rid of it despite your best thinking or hypothesis of why it couldn't,shouldn't work. Go against Logic and Go out and try Mr. Bruce Plecan's compressor surge fix you will become a BELIEVER immeadiately once you see how smooth your car responds, once you feel your car stop bucking and she takes off. Picked mine up at PEP Boys last night on the way home from work 54 bucks. Best 54 bucks I've spent of late. Thank you Bruce RIP.

 

[turbojimmy]

Upon sending DRBOOSTER a PM about placement went out and bought a ki-75 (75mm. or 3")Tornado took a couple minutes to install, fit perfect in the 3" intake hose and butted right up to turbo inlet. Went out and thrashed the car no compressor surge WHATSOEVER, nuthin, natha, zero, zilch, it was a PLEASURE again to lay into it with out it breaking up. So if your a non Believer and have severe surge and can't get rid of it despite your best thinking or hypothesis of why it couldn't,shouldn't work. Go against Logic and Go out and try Mr. Bruce Plecan's compressor surge fix you will become a BELIEVER immeadiately once you see how smooth your car responds, once you feel your car stop bucking and she takes off. Picked mine up at PEP Boys last night on the way home from work 54 bucks. Best 54 bucks I've spent of late. Thank you Bruce RIP.

That's awesome. I don't think they make a 4" Tornado though

Jim

 

[ChavoLC2]

Yes they do.

Ki-100 is 3 and 7/8"s almost 4" they make them to fit a hose that 1mm smaller and 3mm larger then stated size.The ki-100 should work just fine. 3mm isin between 1/16th and 1/8th of an inch. Go to PEP boys and pick one up it will work. I would put a clamp over the area of hose and tighten it enough to keep it in place so it doesn't migrate forward or backward..It should sit flush up against the inlet lip. Cool you will be Happy to not have that darn surge. Let me know how it goes.

Mr. Armstrong thank you for sharing your thoughts on Mr. Plecan's next idea insight..

 

[Jack Armstrong]

Tornados Are Available For Four-inch Ducting

That's awesome.



I don't think they make a 4" Tornado though

Yes, there is a Tornado available for 4" ducting.

Nothing would've made Bruce's day more than knowing
he'd been able to help someone through his constant
experimenting, testing, tuning, "tracing" and tinkering.

In many ways, Bruce Plecan was the TR-world's "Smokey Yunick".


HTH

 

[Jack Armstrong]

What is/was Bruce Plecan's screen name?

"bruce" here, years ago.


During the last years of his life, he spent much of his web-time as

"Doc1of7" on the other 2 Turbo Regal community messageboards,

as well as many ECM/EFI boards and various other car enthusiast boards.


If someone did research & read all his threads & posts, they'd quickly see

the amount of derision and disrespect to which he was generally subjected.

They'd also see, through it all, Bruce Plecan just kept on keeping on.

 

[D's GN]

My previous turbo was a Turbonetics 66mm BB with a 4" inlet / 2.5 outlet, just an awseome turbo which helped me run easy tens. The only problem with it was at part throttle around 10-12# boost the car would surge/buck like crazy. The only way around it was to either let of the gas quickly (Tial BOV) or power through it with more throttle which cleared it up. The turbo I run now is a Turbonetics GTK-650 essentially the newest version of the 66MM with an S-trim exhaust wheel. The inlet on the turbo has these "bullet" type slots which alleviate surge. I was skeptical at first but when all the conditions were the same 10-12# at part throttle the surge was all gone, maybe just a slight hint of it with the boost guage needle moving ever so slightly up or down. Driveablility is great. Here is a picture of the turbo inlet.

 

[ChavoLC2]

That's one bad lookin Turbo

Well maybe more of the Turbomakers will employ a similar design . That's awesome that Turbonetics worked that into the design of their inlet. I couldn't be more happy now that the surge/bucking is gone. Yeah my buddy come by didn't believe me I guess as he had gone for a ride about 3 weeks prior car was bucking /surging went out today after I told him the Tornado cleared it up. He's going to pick one up .Nice to have smooth linear response.

 

[turbojimmy]

Well maybe more of the Turbomakers will employ a similar design . That's awesome that Turbonetics worked that into the design of their inlet. I couldn't be more happy now that the surge/bucking is gone. Yeah my buddy come by didn't believe me I guess as he had gone for a ride about 3 weeks prior car was bucking /surging went out today after I told him the Tornado cleared it up. He's going to pick one up .Nice to have smooth linear response.

I had asked Jack Cotton just yesterday whether that GT-K compressor housing could be used on my T70. He thinks not. Though I can get a T70 compressor cover with anti-surge porting.

The 3 7/8" Tornado worries me. I wouldn't want it to come loose and have the turbo eat it. It looks flimsy in the pics. I don't know if the smaller ones are sturdier.

Jim

 

[ChavoLC2]

Tornado

Yeah if you can afford a new comprssor housing that would be great. Like what 87GN-D says the bullets machined into inlet ALLEVIATE the surge. Plus you'd have better peace of mind.

 

[turbojimmy]

Yeah if you can afford a new comprssor housing that would be great. Like what 87GN-D says the bullets machined into inlet ALLEVIATE the surge. Plus you'd have better peace of mind.

I don't know if I can afford one or not....how much can they cost?

Jim

 

[turbojimmy]

I put a Turbonetics Godzilla BOV in the car. If you don't like 'em don't read on since it will probably just piss you off.

The Godzilla has 2 ports, one on each side of the diaphragm. The idea is that it will open and close faster with boost on the one side and vacuum on the other. What this also does is allow it to open at part-throttle where I was having my surge issues. When the boost in the up-pipe overwhelms the spring and diaphragm it starts to bleed boost off. It's not just an open/closed throttle operation. At part throttle, at around 5 PSI I can hear it bleeding boost. If I hammer the throttle it will snap shut instantly and the boost shoots up.

Pics and vids:

[youtube]http://www.youtube.com/watch?v=CdrViA9i0yc[/youtube]
[youtube]http://www.youtube.com/watch?v=CHZhjrEwgd8[/youtube]

From underneath:

From up top:

Jim

 

[GNVYUS 1]

Were you holding mid level boost in the first vid during the first run??
It sounds like some sort of wheezing is happening but I can't see the boost gauge.

 

[turbojimmy]

Were you holding mid level boost in the first vid during the first run??
It sounds like some sort of wheezing is happening but I can't see the boost gauge.

Yeah, the wheezing is the bleeding of boost at about 1/2 throttle. I didn't open it up much until I got past that one house on the left. The guy is friends with my dad, didn't want to make too much noise. And then toward the end of that first vid you can see a dude walking. That's why I got out of it quick.

I don't have any WOT vids. There is really no room in the state of NJ for a WOT blast for more than a second or two. I tried but couldn't make it happen. Above 1/2 throttle the BOV closes. I can tighten the spring and/or remove the boost from the second port. Doing either or both will keep it shut at part throttle. The problem, I think, is that it's moving a lot more air than I can use at part throttle so it was surging even when I was into the boost a little (like 5-10 PSI). Now, with the boost hooked up to the BOV, the diaphragm is opening under the same conditions because of the imbalance between the pressure in the up pipe and the manifold, which is what I hoped it would do.

Jim

 

[cstavro]

fwiw, 100 mm is 3 15/16". considering a 4" tube is OD, it'll be a snug fit inside.

 

[GNVYUS 1]

Never heard about the Godzilla but it looks like Turbonetics did a good job with that one. With the dual ports it appears to be the one BOV that will stop mid level boost surge.

Looks like there are three ways to go now to stop mid level boost surge.

( cheapest to more expensive )

Tornado
Ported Shroud Compressor Cover
Godzilla Blow Off Valve