Just installed a joe p xz mbc. Took it out for a test drive and slowly turn it up when we find out what boost we're hitting. We're getting right aroung 8.9 lbs of boost and while we're in 3rd gear right around 3500 rpm there is a violent buck Then the boost drops to around 8.3 lbs. It bucks every time. I thought fuel cut was at 9? We are running a blitz duel turbo timer boost gauge. Basically .60 hkpa, then we multiply that by 14.7 to equate the psi. So when we hit .60 hkpa it drops down to .55 wich is 8.0 psi. We just don't know what's going on. We have the turbo timer is hooked to the small line that runs to the blow off valve. Thanks for your help.
mbc problems
- Thread starter mzdmark
- Start date
So does the JOE P FCD eliminate the buck totally or not? MS MSP it looks to me like you have it but does it still happpen to you? Also, if i set the boost for 9psi, its normal for it to drop down once i get into turbo range? I use 93 octane, but will 94 octane help this situation at all?
evo..eater:)
Member
- :
- 2003.5 Mazdaspeed Protege
I believe that Joe's FCD does work 95% of the time. The only time that I have seen it not work so good is when you are trying to run 18 PSI "Discreetspeed". Just so you know, which I have learned here recently. The denser the air the more likely for fuel cut. Sometimes I can run all the way up to 12 PSI with no fuel cut or FCD. I believe that the highest you can boost on our cars is 12 PSI at stock stage (no FCD). Well I hope this helps you out.mzdmark said:
I know that there are two different FCD's on the market that will work for our cars:
JoeP (Do not know if he is selling them anymore) $$$?
Essential Speed (Waiting on resistors should be a couple more weeks) $65
mazdaowner123
Member
It's not neccessarily PSI based, more based on air density. That's why you'll hit it at lower PSI on cold days, because the air is more dense.
~brian
~brian
I don't have the FCD or FPR in yet. I'm waiting to install my exhaust and plugs and for the weather to stabilize here before deciding whether to use it or not.mzdmark said:
Right now, i can't go WOT if i floor it without hitting cut.
If i squeeze the throttle, I can get to WOT.
The temperature has been really up and down here though.
jersey_emt
Member
- :
- 04 MSM #1089
mzdmark said:
I't normal for the boost to fall off at higher RPMs. Especially if you have the stock IC piping and the stock exhaust.
I installed it yesterday on a colder than normal day. This morning on the way to work i had turned it down a notch to see if it would stop the bucking. It did but it was probably because today was a much warmer day than yesterday. I guess i will be sending JoeP and email asking him if i can still purchase a FCD.conekiller said:
send him an e-mail. Very nice guy I just bought mine a couple of days ago I can't wait to install. I actually had some 12psi goodness today for a bit before the cut hit. Needless to say 10psi to 12psi the difference is night and day....very quick I wish we could run 12 all the time.....I gotta go forged...hehe
12psi is flirting with danger....although I've done it. I don't intend on keeping it there long. One thing to consider is every engine is different. I run 94 octane sunoco and have been for the life of the car. At 12 psi I heard no knock at all. I've also seen posts where people get knock at 10 and up to 12 psi. jersey_emt ran into a situation where he spiked to 13 and heard knock. 10psi is safer and 9-9.5 should yield no problems. I'm gonna keep it at 10psi just for safety. I have MBC,Intake,Exhaust,Spool FMIC,the colder ngk plugs (extended reach) and upgraded magnecor igition wiring.
(yippy)
(yippy)
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Just went to the JoeP website and apparently he opened it up again to MSP owners. I sent him and email anyway asking about availability for the FCD. Even when i get the FCD i am only going to run between 9-9.5 psi just cause i dont want to blow my engine. I have been running 93 octane from sunoco since i got it.
That is fuel cut that you are having and yes my FCD will help you 
..
On another note- do you know what temp it was when discreetspeed hit fuel cut at 18 psi? I didn't hit until almost 21, but that was on an upper 60 degree day. Gotta be careful with how much resistance you use- the MSP likes to throw a CEL and go into limp mode
.. I can make it "stronger", but if you are cutting with my FCD, you are at a point where you need a lot more than an FCD and by that point an FCD won't be necessary (standalone, piggyback, etc). If you are running 18 psi, you need a LOT more than an FCD to keep it safe- unless you use race fuel all the time like I did . Still pushing it though.
So essential is making them now too? Any links to his (always good to check out the competition )?
By the way, yes, I still sell the MSP items, I kept it as special order only for a while, but with the amount of special orders I have been getting, I decided to just put the page back up since I am still selling just as many. I am actually going to post that now.
Joe
..On another note- do you know what temp it was when discreetspeed hit fuel cut at 18 psi? I didn't hit until almost 21, but that was on an upper 60 degree day. Gotta be careful with how much resistance you use- the MSP likes to throw a CEL and go into limp mode
.. I can make it "stronger", but if you are cutting with my FCD, you are at a point where you need a lot more than an FCD and by that point an FCD won't be necessary (standalone, piggyback, etc). If you are running 18 psi, you need a LOT more than an FCD to keep it safe- unless you use race fuel all the time like I did . Still pushing it though.So essential is making them now too? Any links to his (always good to check out the competition
)? By the way, yes, I still sell the MSP items, I kept it as special order only for a while, but with the amount of special orders I have been getting, I decided to just put the page back up since I am still selling just as many
. I am actually going to post that now.Joe
evo..eater:) said:
Lol@ the comments about the site . I didn't read them until after I posted this.. Yeah, like I said- sales didn't really drop off after I took it down any, so I figured screw it. It beats answering a bunch of "can I still get this" emails .
Joe
. I didn't read them until after I posted this.. Yeah, like I said- sales didn't really drop off after I took it down any, so I figured screw it. It beats answering a bunch of "can I still get this" emails .Joe
kwiktsi said:That is fuel cut that you are having and yes my FCD will help you
On another note- do you know what temp it was when discreetspeed hit fuel cut at 18 psi? I didn't hit until almost 21, but that was on an upper 60 degree day. Gotta be careful with how much resistance you use- the MSP likes to throw a CEL and go into limp mode
So essential is making them now too? Any links to his (always good to check out the competition
By the way, yes, I still sell the MSP items, I kept it as special order only for a while, but with the amount of special orders I have been getting, I decided to just put the page back up since I am still selling just as many
Joe
