6776 BB surge

T

TKGN1

Member
Joined
Mar 11, 2002
Stepped up from a pt54 to a 6776 BB. Drove the car last night and noticed quite a bit of compressor surge even when I let off fairly easy. Any body else with a BB experience this? Normal?
Also, should the internal wastegate be able to handle controlling boost (up to around 25lbs) with this turbo?
 
Are u talking about a sneeze back thru the air cleaner when you shut the TB blades quickly?

If so mine does it too. Sounds like a camel that ate 20 lbs of beans!:eek:

You are gonna love that turbo...
 
Yep, thats it. Its waaaay more apperant than my 54 was, wasn't sure what to think when it happened, even when I passed a car on the freeway and let off very slightly it did it. I guess because the turbo spins so freely and quickly it is more prone to surge than the smaller turbo.

Are you running an internal wg or external? was told the internal could handle up to around 25 lbs boost, but I haven't throttled past about 18 lbs yet. I thought about unshrouding and porting the wg hole (did it on my 54 with no problems).
Thanks
 
external..

18 psi???? that turbo hasnt even begun to wake up yet.

Let me know when u hit 25:D
 
i put mine on sat still have tune it.....im at 23lbs and love it still have more boost in it..cant wait!!
 
Turbo6 has an internal wastegate and he was having issues. PM him and see what he did.

Or just wait..he will see the 6776 thread and reply.
 
mine has the HD actuator.. 22-25 psi is low as it goes.. i need to port out the wastegate hole
 
Hmmm what's this I'm hearing about internal wastegate troubles.... was planning on a 6776, wasn't planning on going to external...
 
I don't want to go external either.
I plan to port the wg hole also, just wanted to see how many others are running the 6776 with internal wg.
I did just finish up maxing the rod out with just enough tension on the puck as well as backing off the RJC valve to allow for min boost, I'll try it later this weekend.

Anybody on the surge? This normal with the BB?
 
Hold your horses guys. Turbo6 or Patrick will chime in on this one. The 6776 is gonna work fine with the internal. They are gonna fill you in on what needs to be done.:)
 
That's not surge you are hearing. I think you are hearing "snort". A common sound when shutting down airflow quickly.
Surge is a phenom seen when the press ratio, and air flow, put the operating point to the left side of the surge line on the compressor map. Bearings can take the hit, if it continues.
 
Sneeze, snort, surge, one of those!
Yes Chuck, its when stopping air flow due to throttle closure.
Is this more noticable when going BB/bigger turbo?


I'm sure someone will chime in on what has or can be done for internal wg.



.
 
it noticable when using a big turbo like this... what were ya using before??
 
My TA62 non-BB, which is similar to a 54, had much more of the air noises than my Double BB Innovative 70 ptrim. The 70 BB is a lot more quiet.

No surge from either turbo, which is the inability to hold partial boost say 5psi. with steady throttle application, it will surge to 8 down to 4 and back up again with the technical reasons supplied by Chuck above.

Internal wastegate 14lb. spring (HD) and two solenoids on a BSTC gives me 18 to 27psi. control.

1.060" hole and THDP 1 3/8" or 1.375" puck.

Cold air kit 4" pipes, 3.5" MAF, and filter under the bumper.

I'd look into boost control issues being possibly your control mechanism, puck hole alignment/sealing and size which usually only helps with boost creep issues.

Noises only on throttle closing is probably due to intake tract, filter location, and the turbo itself, most likely nothing to worry about.

Just my .02.
 
Thanks for the input.
I just put the turbo on Tuesday and noticed a few new "noises", wanted to get a little feed back from others with the same application.
Thanks again.
 
when i switched to the 70mm turbo and 4in maf pipe with cold air intake it sounded LOUD, almost as loud as a blow off valve.
No one around here knows what it is, but they here when i lift at the track:(
No sand baggin;)
 
You must log in or register to reply here.

Similar threads

M
Boost Control Issue - need direction on next step
2
Replies
25
Views
4K
hemi8
hemi8
Grandpa’s 87
The story of Grandpa’s 87 Turbo Buick (Full)
Replies
12
Views
3K
Marty Fairchild
M
Steve87GN
Turbo and Intercooler Alignment
Replies
7
Views
1K
V6POWER
V
T
inconsistent surge. hard to pinpoint the problem.
2 3
Replies
42
Views
4K
Thomas Steven Booth
T
SteveZ82
Fresh AC Charge - R12
2
Replies
29
Views
3K
SteveZ82
SteveZ82
Top