So I went to the dragstrip today...K&N intake, Catback, and boost controller @21PSI. 4 runs and I couldn't break 14s. 14.015 Best time with 1.88 60ft. Another evo there with intake, MBC, +full exhaust, running low 13s.

I'm talking to him, and I basically came to the conclusion that I suck at drag racing. He asked maybe I was leaking boost and I thought no way, I went to AMS and had a boost leak test and had them replace the spring in my MBC. They said I wasn't leaking boost.

Sure enough on the way home I figure...might as well try and check, and sure enough... boost goes to 1.4 BAR hold steady for 4-5k RPMS, then tapers to 1.2 Bar ~6k and after 6.5k it falls to 1 Bar.

So...my question is WHY?! I'm so fustrated. I spent 60 dollars on the MBC, and then 150 for that boost test and I'm still not holding boost... I'ts almost like stock, I might as well taken that money and invested it in ... **** or something.

Anyways, I just have a couple questions and I was wondering if these factors are related to holding boost. My intercooler sprayer wasn't on when I was trying to figure out my boost, would that have a large factor in it? ( If so I'll go try again tomorrow.) Also about that clamp tightening? Would that be very useful? Would holding the boost help my quater mile time by alot? (I realize my driving skills aren't very hot, and that my times are oh so sad ) The guys at AMS said there was no boost leak and I trust them so anyone have any ideas? Faulty boost gauge?(Used Greddy Electronic I got with a discount).
Perhaps I should just get my car dynoed?

here's my full timeslip if that helps to determine if my car is fine and I just suck(very possible!)
Rt:.406
60' 1.880
330 5.724
1/8 8.920
MPH 76.41
1000 11.707
1/4 14.015
MPH: 97.12


Sorry mods if this is sorta drag racing and boost problem...But they are pretty related and I don't quite know what to do Could it be that my BOV is leaking?

edit : 1.4 bar = ~21 LBs 1.2 = ~17 Lbs 1 = 14.5 just to make it easier.

 

stock recirc. blow off valve cant really take 21 psi dude...

 

true dat...

 

... then it should have stayed at 20-21 psi and not drop to 14. It's been proven some Evo's are faster than others. Maybe you have one of the slower ones . All is not lost though, just get more mods and some sort of Re-flash , piggybacks or S-afc.

The other guy who was running low 13's, He could have been on race gas and boosting higher. Or he could've one of the faster Evo's .

 

Gotta get the HKS SSQV, baby!!!

 

1.44 is 21 psi. I've hit 1.5 but usually I peak at 1.45 and then taper down and this is without a boost controller. Your 60 ft time could be better and by the looks of your total times you need to work on your shifting.

 

so...i should get a new BOV? I was under the assumption that the stock one was pretty good...guess not.

 

That would help, I like the Greddy Type S, works better then stock, that is for sure...



My guess would be the MBC, I had the same problem, now my car holds 1.45 all teh way to red, very fast.

 

what MBC?

 

Slightly off topic but as anyone bust a stock BOV due to high boost? My car is acting funny. boost fine to 7psi but then it falls apart like I'm leaking boost some where
-James

 

The Stock BOV leaks from the factoru 100% Stock. It has a Tight spring that will hold 19PSI, no problem, but there is no seal, so even when the BOV is closed, it leaks, just the design I suppose....

 

also off topic: but I ordered the Evo MR BOV. Will it leak too???

Krunal

 

Yeas HKS SSQ BOV Evo specific, will hold the boost!!! Even without a MBC I have noticed that boost stays on stronger and longer into 6k!

 

could it be I have a faulty wastegate? would that show up in a boost leak test?