boost control... what's that?

[MyBeatGSX]

How many other people have horribly inconsistant boost? I feel like my MBC works merely as a suggestion and the car does whatever it wants after that. I don't even think the majority of it is creep. I have very consistant creep, starts at 6,000rpm and hits 25psi by 7,000rpm. This car LOVES creep, even my small 16G crept to 25psi. Now my brand new and heavily ported Evo (w/atmos dump) does it as well. But that's not the issue.

The problem is that every time I put the pedal to the floor I get different boost, even from a low rpm 3rd gear roll on. Its set at 21psi, however, rolling on in third gave only a hair over 20psi on the dyno and then gave 22psi on the street immediately after that. Tonight I stomped it at 4,000rpm in 2nd and it jumped right to 24psi and held there, no spike, just jumped and held. Earlier today it was only 22psi, this morning it was 21psi, last night it was 23psi. This has very little to do with temperature change because it was much warmer and more humid last night then it was this morning, and I still saw more boost last night.

Its like a mystery, I guess it adds excitment to the drive and keeps things new and fresh.... what will I get this time, 19psi? 25psi? 23psi? a blown motor? What's next? Anything but what I have it set at I'm sure.

I realize an external gate will solve my problems and I plan on getting one, but I'm just ranting. I KNOW there are people out there with properly functioning internal gated turbos.

 

[CanadianTSi]

I run the Older Greddy Profec B and I get the exact same boost day in day out regardless of temperature.

Maybe try switching to a different MBC or EBC.

 

[MyBeatGSX]

I'm seriously thinking about getting an EBC.

I heard that Profec B is the best and obviously you like it. Have you heard anything about the Profec RS? I looks the same, just supposedly a newer, better design.

 

[DSMunknown]

I heard that Profec B is the best and obviously you like it. Have you heard anything about the Profec RS? I looks the same, just supposedly a newer, better design.

Do you mean the Profec Type S? Or the Profec B Spec II?


http://greddy.com/products/display/?Category=electronics&SubCategory=51

http://www.extremepsi.com/store/customer/product.php?productid=16138&cat=277&page=1
http://www.extremepsi.com/store/customer/product.php?productid=17396&cat=277&page=1

 

[MyBeatGSX]

Yea the S, my bad.

 

[92awddsm]

How many other people have horribly inconsistant boost? I feel like my MBC works merely as a suggestion and the car does whatever it wants after that. I don't even think the majority of it is creep. I have very consistant creep, starts at 6,000rpm and hits 25psi by 7,000rpm. This car LOVES creep, even my small 16G crept to 25psi. Now my brand new and heavily ported Evo (w/atmos dump) does it as well. But that's not the issue.

The problem is that every time I put the pedal to the floor I get different boost, even from a low rpm 3rd gear roll on. Its set at 21psi, however, rolling on in third gave only a hair over 20psi on the dyno and then gave 22psi on the street immediately after that. Tonight I stomped it at 4,000rpm in 2nd and it jumped right to 24psi and held there, no spike, just jumped and held. Earlier today it was only 22psi, this morning it was 21psi, last night it was 23psi. This has very little to do with temperature change because it was much warmer and more humid last night then it was this morning, and I still saw more boost last night.

Its like a mystery, I guess it adds excitment to the drive and keeps things new and fresh.... what will I get this time, 19psi? 25psi? 23psi? a blown motor? What's next? Anything but what I have it set at I'm sure.

I realize an external gate will solve my problems and I plan on getting one, but I'm just ranting. I KNOW there are people out there with properly functioning internal gated turbos.

Have you tried any mbc other than the turbosmart? I have heard of problems with the turbosmart so I would try something different if I were you. I have the hallman es and it worked flawlessly with my 16g, to4b v-trim, and now with my 60-1 which is internally gated.

 

[MyBeatGSX]

The turbosmart is actually working better than my Hallman ES. I spool about 200rpm sooner and its just as inconsistant.

What sort of problems have you heard of? I knew there must be a reason I'm the only one using one. doh!

 

[LRS95TSI]

i keep hearing people talking about bleeder valves on boost controllers...i got a mbc from dejon tool and ppl have told me that i need a bleeder valve..is the turbosmart ball and spring...people say those are always better....leaving this for discussion as i'm not up to date on what works best

 

[brute]

I made my own at it is always consistant. Boost never faulters or comes on slow.

 

[Apeximprt2nr]

http://www.dsmtuners.com/forums/showthread.php?t=242250

My Joe P. MBC and my brothers Hallman ES BC both do that. I don't think it's anything to worry about.
I suggest looking at that thread.
Engine load, gear, and RPM's , along with weather will effect your boost.

 

[daren_p]

Obviously you won't see full boost in first & sometimes second depending on the turbo but 3rd on should be fairly repeatable (spool time will vary some), same with temp it will have some effect but not the amount of variance your talking (I imagine barametric pressure will also play a small role). I have run the turbo xs, joe p mbc & the greddy profec type S and they all haven't varied very much, were talking up or down 1 psi at most from the set point & I usually don't see that. Currently this is on a shimmed internal WG. I would say something is up, seems your setup likes to creep alot more then normal as well.

 

[MyBeatGSX]

http://www.dsmtuners.com/forums/showthread.php?t=242250

My Joe P. MBC and my brothers Hallman ES BC both do that. I don't think it's anything to worry about.
I suggest looking at that thread.
Engine load, gear, and RPM's , along with weather will effect your boost.

Good link.