lol, no it's not running wastegate pressure or freeboosting. Running a GM 3port.

 

What kind of cams etc do you have? So much of your power has to do with overall build components. You can't just go pointing the finger at a turbo being the bottleneck. Have you checked to see if you're wastegate is sticking open? Mellon did a great write up about this just a little while ago.

Have you done a leakdown test?
What is your mod list?

 

Yea sorry I forgot you mentioning WGDC's in the last post of yours.

What turbo did you have before this?

Do you mind sharing logs of your car?

 

Can I please get a linky to that Melon thread about the wastegate sticking open. I have not checked this yet.

Like I said, not a CBRD bash, just trying to get to the bottom of things. I shouldn't have said the worst turbo I have ever owned as I cannot prove 100% that it is the turbo yet. If it is not I will happily eat my words.

No leak down test yet but it's looking like its on the cards. I will post logs later on today 11am here. When I get home from work I will post up. You will notice loads are erratic.

 

I understand you're giving up some information but you're missing out on a few keys here like what pressure you're running for instance. Are you getting a new map sensor or boost gauge? What about your afr's? Who's your tuner? Has this all fallen apart since you got this turbo like you installed the B and your boost gauge and map sensor failed or had they failed on your last set-up? Was your tuner tuning your car based on having no boost pressure feedback?

 

http://www.mellonracing.com/index.ph...roducts_id=953

 

I have a new gauge on the way. So will have that info for you asap, Also in the middle of swapping out my worn diff so will be out of action for a little bit.

AFR's are what they are supposed to be for meth/water pump combo. Tuned by someone who tunes a lot of evo's for great results. The tuner also runs an aquamist on his own evo 6 and knows how to get the most from it.

I will try to get as much information as possible, as I am not trying to play the blame game but just trying to get my system working.

PS: thanks for the link - I have indeed adjusted the preload on the WGA to full and is cracking at 24psi. I thought you meant it might be the actual wastegate flap not seating properly and letting boost escape. I am seeing very high WGDC of about 80%.

 

Cracking at 24 PSI is good and tight! So, that shouldnt be the cause of the laziness.

Incidentally, I think that Chad configures the BBK's with the stock actuator if I am not mistaken. Does he also use the stock actuator on the BBK-B?

 

Yes that is correct the BBK-B came with a stock like WGA which cracks at 13-14psi on factory preload and about 15-16psi on full preload.

Anyone running the B who hasn't adjusted the pre-load should consider it

 

I know everyone starts with a boost leak test and that's good but remember that exhaust leaks between the head and header or header and turbo can cause lazy spool and dismal performance as well. I've had more than a few cars show up like that to be tuned where their gasket blew a corner out.

 

Great info; thanks for sharing that. Is there typically visual evidence of that, if you're looking for it (i.e., a pattern of black soot distributed from the leakage point) or can it be pretty much invisible and still be a significant leak/problem?

Definitely feel your pain. Most of us know how exactly how frustrating it is, and how pissed off we get, when things aren't working right... esp. when you don't know why.

 

sometimes it's obvious like that where you can tell audibly and see the blackend stains. Sometimes I have to get in there while it's idling and shove a wadded up rag into suspect areas and listen for the tone to change.

 

Ummm...I am interested in seeing more results once you have a new MAP sensor & boost gauge on the car...I know a lot of people swear by ECU controlled boost now & it seems like your WGA is preloaded well enough but for sh*ts & giggles have you thought about throwing a MBC (Hallman or Forge with the stiff spring) on the car & trying it out? Also does anyone local to you have an FP 25psi WGA you could throw on the car & try out? I also agree with the possible exhaust leak comments, what manifold are you using, stock ported? What 02 housing, aftermarket recirc?? Good luck, hope you get it figured out, keep us updated!

 

Thanks for the info guys, I am using a stock E7 manifold with a reversed MR Bov. I don't think they can leak when flipped. ?

I will look for any signs of exhaust leak, but it doesnt really sound like there is under idle, but these things can be hard to pin point so will double check it for sure. I really don't think that it is a boost control issue at this point as we have an actuator cracking at 23-24psi and have used no less than 3 different actuators all producing similar results.

I have actually lined up another turbo to bolt on. This should tell us pretty quickly if its the turbo or a mechanical fault of my own. I will be sure to keep you guys posted.

Quick thanks to Chad for no less than 10-15 e-mail reply's now trying to sort this with me.

 

A couple of things....You are running a large displacement motor, so seat pressure at the WG valve is gonna be way higher due to increased exhaust pressure inside the turbine housing compared to a 2.0L. engine. I would follow the above advice from B.J., and try a HD FP WGA(18, or 25 PSI) and preload the **** out of it. I would cut about three threads off the tip of the actuator rod right off the bat.

When you said that cracking pressure was 25 PSI, I guess that I misunderstood. I thought that you meant that the WG puck was not lifting off the seat until 25 PSI. But, you meant something else.