BBK Full compressor surge at only 27 psi?
Feb 8, 2011, 09:01 PM
#31
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Ha 
Ha Ha Ha. LOL. I installed the original version 64mm unported FP Red on my Evo VIII along with a chopped down, 1/2" shortened FP 18# WGA(read tons of preload), and an unported 10.5 turbine housing(read tons of creep), and a totaly overcrushed IX DV(read very touchy and fluttery).
This thread has my full attention eventhough it is about the OP's BBK-Full turbo.
Ha Ha Ha. LOL. I installed the original version 64mm unported FP Red on my Evo VIII along with a chopped down, 1/2" shortened FP 18# WGA(read tons of preload), and an unported 10.5 turbine housing(read tons of creep), and a totaly overcrushed IX DV(read very touchy and fluttery).This thread has my full attention eventhough it is about the OP's BBK-Full turbo.
Feb 12, 2011, 08:01 PM
#34
I used to have wicked surge with the FPWhite. I loosened up the WGA 1.5 turns and BAAM, no more surge! Like, never.
I have the standard wastegate on there but it was not opening enough and with the quick spool of these smaller turbo's, it makes sense.
Give that a shot first Rich, can't hurt any and I did not see any difference in spool up.
I have the standard wastegate on there but it was not opening enough and with the quick spool of these smaller turbo's, it makes sense.
Give that a shot first Rich, can't hurt any and I did not see any difference in spool up.
Thus far, I really like the turbo. Good torque (25-26 psi by 3700 rpm or so on a 2.0!) and better top end than I was expecting compared to the Red/Black. Looks like I'll be putting my Black up for sale as soon as I can get some pictures taken of it and get it boxed up.
Feb 12, 2011, 08:40 PM
#35
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Awesome, glad it helped. I was going crazy for awhile with mine. My biggest problem was I bought the white when it first came out and it was 1400 big ones. I was going to add the surge cover, but @ another 200 I didn't want to, especially since the price is now 1149 WITH a cover now.
I would rather upgrade =)
Take another half turn out, can't hurt right? I had the same thing, right around 4000 or so it was horrible. Now I only get a tiny bit if I am in 5th gear going slow and it is only brief, and this never happens. I only did it going through the gears to see if it actually goes away.
I also never saw any loss of spool, but this is a tiny turbo anyway
I would rather upgrade =)
Take another half turn out, can't hurt right? I had the same thing, right around 4000 or so it was horrible. Now I only get a tiny bit if I am in 5th gear going slow and it is only brief, and this never happens. I only did it going through the gears to see if it actually goes away.
I also never saw any loss of spool, but this is a tiny turbo anyway
Feb 13, 2011, 01:29 AM
#36
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Evo8LTW tell me more about that 3" intake. Everywhere 3"?
Feb 13, 2011, 10:25 AM
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compressors are very sensitive to inlet conditions. How the air goes in, determines how it comes out of the impeller. Especially with regards to surge. Inlet pipe diameter, how many mm of straight before wheel, are all factors. I've got a thread going to gather info from everyone, you might chime in.
In the interest of finding out what will fix your problem, you might want to bolt on the stock intake tube and see if that makes the problem better. Not to say that is a permanent solution because that tube is horrible, but it might give direction to a solution vs spending tons of money on compounding the problem.
In the interest of finding out what will fix your problem, you might want to bolt on the stock intake tube and see if that makes the problem better. Not to say that is a permanent solution because that tube is horrible, but it might give direction to a solution vs spending tons of money on compounding the problem.
Feb 20, 2011, 03:18 PM
#41
It seems that I've been able to tame the surge mostly by keeping things below 25 psi until 4000 rpm, using tephra v7 gear-specific boost tables. The turbo is definitely capable of spooling much faster though -- I was seeing 27 psi or so at 3700ish (albeit with surging sounds) before I made the boost profile more gentle.
One other issue I'm battling now is boost creep in 4th and 5th gear when trying to run moderate boost. I'm working first on a road race tune where I plan to keep the boost down to 25 psi. I'm seeing 26 psi above 6000 rpm or so in 4th and 5th gear, even with 0% WGDC. I suspect that the wastegate hole in my O2 housing may need to be ported. At least boost taper is no problem!
I'm going to be pulling it off anyhow to try out the FP compressor housing and see if it allows me to spool the turbo faster without surge. I figure it's a cheap experiment for $75 shipped and I need to do something about the O2 housing anyway.
I love the turbo though. It responds way faster than my old red or black and the top end is indistinguishable at 25-26 psi (overall actually feels faster because of the broader powerband). I haven't tried running the boost any higher yet (I ran my Red and Black at 30 psi on 93), because I want to get the low boost tune right first. I had thought it would make around 400 whp dynojet at this boost level, but the preliminary logs are looking like at least 425+ whp easy, even with low timing and low 11 AFRs. I bet it easily goes over 450 whp on 93 octane whenever I get around to doing a street/drag oriented tune. Fun!
One other issue I'm battling now is boost creep in 4th and 5th gear when trying to run moderate boost. I'm working first on a road race tune where I plan to keep the boost down to 25 psi. I'm seeing 26 psi above 6000 rpm or so in 4th and 5th gear, even with 0% WGDC. I suspect that the wastegate hole in my O2 housing may need to be ported. At least boost taper is no problem!
I'm going to be pulling it off anyhow to try out the FP compressor housing and see if it allows me to spool the turbo faster without surge. I figure it's a cheap experiment for $75 shipped and I need to do something about the O2 housing anyway.
I love the turbo though. It responds way faster than my old red or black and the top end is indistinguishable at 25-26 psi (overall actually feels faster because of the broader powerband). I haven't tried running the boost any higher yet (I ran my Red and Black at 30 psi on 93), because I want to get the low boost tune right first. I had thought it would make around 400 whp dynojet at this boost level, but the preliminary logs are looking like at least 425+ whp easy, even with low timing and low 11 AFRs. I bet it easily goes over 450 whp on 93 octane whenever I get around to doing a street/drag oriented tune. Fun!
Feb 20, 2011, 05:29 PM
#42
The turbo to me seems to respond on the aggressive side to positive WG input. Like a few more WGDC% can easily send it from 27psi into the oooops area. I really dont drive that far below VE (3000rpm) but can see surge be a possibility
Last edited by C6C6CH3vo; Feb 20, 2011 at 05:32 PM.
Feb 21, 2011, 07:44 AM
#43
I am interested to see your results with the FP compressor housing and higher boost...I ran my BBK Full at 27 psi and as far as I know never had surge issues, I was having issues with my Tial Q bov at the time though...Chad tuned my car with a mild timing map (road course tune) and it made a little over 400whp and 370wtq on his dyno @ 26.5psi & 93 oct...This was done with stock block, full bolt-ons, S2s, etc...For the WRX/Evo Showdown at Englishtown I put a more aggressive timing map in the car and it was definitely noticeable...I am guessing it was around 420whpish...With your built motor & SD I don't see 440whp being a problem for you on 27psi+ on 93 oct...
Feb 21, 2011, 10:11 AM
#45
Again, If I didnt downshift and thought the car was a V8 and started my pull at 3k rpm in 4th I'd get surge. If I downshift into 3rd and start the pull at 36-3800 it wouldn't surge. This was on E85 33psi BBK (485-500whp Dynojet). Now I'm rocking the Black and it doesn't surge at all.