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Help!, Boost Spike!...

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Old 04-29-05, 03:16 AM
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Help!, Boost Spike!...

As the name says, i have a question, my mods are as listed:

- 3" Racing Beat Turbo-Back Exhaust
- Blitz SS BOV
- Tein Coilovers and springs
- Centerforce Dual-Friction clutch
- HKS PFC F-Con
- HKS GCC
- HKS Turbo-Timer
- FCD
- SRP Boost controller
- Autometer boost and A/F guages
- MazdaSpeed steering wheel
- MazdaSpeed racing pedels
- Manaray 6spoke 16" rims
- Yokohama Z-Rated rubber

When i floor it in 4th and 5th and boost is made it spikes at 15psi then goes back too 10psi, other gears it goes from 13psi spike too 10psi, i was wondering, i have a manual boost controller and want to install it, what do you guys think, i am buying a walbro 255lph fuel pump soon aswell but wanted your guys' opinions, can i put the boost controller in and somewhat help this situation of mine and level boost at 11-12psi or wait for the fuel pump, how could i control the ammount of fuel going in if i get the pump?...

anyways, thanx in advance, there was other things i would like to ask but not right now, i cant remember some....

Oh, when should i upgrade the fuel system, i have a good hunch RIGHT AWAY, i watched my A/F guage and all seams normal throughout the power band so i'm confused, even with the 15psi spike, help!...

Last edited by Archangels; 04-29-05 at 03:19 AM.
Old 04-29-05, 09:34 AM
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Get the wastegate ported that should help
Old 04-29-05, 10:37 AM
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can i do anything in the mean time...?

i was going to send my whole turbo off too BNR when winter sets in....

plus is it anything to worry about if i do the fuel pump and boost controller?...
Old 04-29-05, 10:41 AM
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Port the wastegate. As far as i know, that will be the only solution to your problems.

-Justin
Old 04-29-05, 10:42 AM
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very true, i was told a boost controller will help a little, but if it's nothing too too major to worry about i'll let BNR do the whole turbo later....
Old 04-29-05, 11:50 AM
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yeah, your best bet is to get your wastegate ported.
Old 04-29-05, 11:54 AM
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Originally Posted by Archangels
very true, i was told a boost controller will help a little, but if it's nothing too too major to worry about i'll let BNR do the whole turbo later....
A boost controller won't lower boost though...it may help stabilize the spike but it won't get rid of it by any means.

If you're on stock injectors, that motor won't last long running 15 psi. Port the wastegate ASAP.
Old 04-29-05, 02:25 PM
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The boost controller will increase your spike because the boost controller prevents/delays the wastegate from opening.

I use to boost creep to 10-11psi in 5th.
I just ported my wastegate and I do a constant 5-6psi in all gears and creep to 8psi in 5th now.
Old 04-30-05, 03:07 AM
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what i'm asking is if i spike at 15psi, with my mods will i be alright, or should i upgrade the fuel pump and/or the injectors....
Old 04-30-05, 03:22 AM
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reguardless your turbo isnt gonna last. the stock turbo really isnt rated for past 10 psi for long periods of time. port your wastegate. i think it takes about 1.5 hours to pull the turbo . if you have put on a downpipe you might want to put the stock cat back on to help lower the boost being made untill you can sent your turbo out to BNR. BTW Brain will do a 30 mm port job with the plaining of the manifold for a extra 100 bucks during the rebuild.
Old 04-30-05, 10:04 AM
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hmm, i'll keep that in mind, if all else fails and the turbo goes i'll buy another, my friend said i could get a hybrid for around $500 canadian if i'm lucky....

i know the turbo wont last all that long, but it has low KM's on it and it's doing fine for now, no signs of wear, i just want to know that my engine will last.... turbo is second on the list....
Old 04-30-05, 11:22 AM
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Originally Posted by Archangels
i just want to know that my engine will last.... turbo is second on the list....
I doubt your engine will last, without the proper fuel mods. i.e. HIGH FLOW FUEL PUMP. Your injectors become the next weaklink.

But, yeah, just incase you didn't read what the last 10 guys said, get the freaking wastegate ported.
Old 04-30-05, 12:28 PM
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You could be leaning out for some reason... Port the wastegate and get an egt gauge, if you are hitting close to 1400 you in deed are leaning out...
Old 04-30-05, 03:26 PM
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I have an ebc with no ported wastegate...I creep to 15 psi all the time mbc/ebc doesn't do crap unless the wastegate is ported. And to make sure I don't lean out when I get my bigger turbo I will put 720cc secondarys so I can run 15 psi when I race But yeah right now when it creeps to 15 psi I let off...don't want my turbo to pop yet
Old 05-02-05, 07:53 PM
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Well the general idea(could be total BS) is that 10-12psi is the limits for safe psi on stock 550's.

I have myself hit 15psi on my car by accident and it did not detonate. I had a walbro and cleaned 550's in it with an Rtek 1.5.

I wouldn't be worried about the turbo. I'd be afraid of a $2k replacement engine.
Old 05-02-05, 08:14 PM
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guys................... boost SPIKE... not boost creep...............
Old 05-02-05, 08:19 PM
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either way he should port the wastegate, it would solve the boost problems.
Old 05-02-05, 08:36 PM
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i would replace his vacuum hose that goes to the wastegate first
his's his probably leaking and opening the wastegate too slowly
that would fix his boost spike....

unless his wastegate has issues
Old 05-02-05, 11:27 PM
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Originally Posted by slpin
guys................... boost SPIKE... not boost creep...............
Boost Spike, Boost Creep...both are uncontrollable boost.


Originally Posted by mazda se
Get the wastegate ported that should help
Originally Posted by Mx6-Rx7 Addict
Port the wastegate. As far as i know, that will be the only solution to your problems.

-Justin
Originally Posted by tjeter
yeah, your best bet is to get your wastegate ported.
Originally Posted by jon88se
Port the wastegate ASAP.
Originally Posted by alwayssideways
...port your wastegate...
Originally Posted by bigdv519
But, yeah, just incase you didn't read what the last 10 guys said, get the freaking wastegate ported.
[QUOTE=Angel Guard Racing Team]...Port the wastegate...QUOTE]

Originally Posted by SmogSUX
mbc/ebc doesn't do crap unless the wastegate is ported
Originally Posted by kd86rx7
either way he should port the wastegate, it would solve the boost problems.
There are another 62,259 members on this website, if you really want to be sure what to do for you boost problem, you can start pm'ing the rest of them starting tonight. I'll be long asleep with a 32mm ported wastegate boosting to 12psi all day, every day, every gear.

Last edited by bigdv519; 05-02-05 at 11:31 PM.
Old 05-02-05, 11:33 PM
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*sigh*
except boost spike happens at the beginning of the boost
while creep happens in high gear, and goes up slowly
you do not even know the difference between them
the problem in his case... is most likely a leaking vacuum hose that goes into the wastegate

remember.... he has a 89... that brittle vacuum line has 16 years for it to crack and leak...

see.... this is seriously a pathetic forum.... with the exception of a few intelligent members, the rest are just followers, saying the same thing over and over again....

from people who thinks they know everything and couldnt even type... to well... people who just follow everyone else and say the same thing over and over....

how would porting the wastegate help when the wastegate isnt even opening at the beginning of the boost...

lets weight something out, ok? port the wastegate, drop exhaust, take turbo out, port it, REUSE his old compressor to wastegate vacuum line... STILL spike....

or just replace the vacuum line, and NOT have it spike....

go ahead... waste your time... be ignorant....

this place sucks... im going home

Last edited by slpin; 05-02-05 at 11:42 PM.
Old 05-03-05, 12:06 AM
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Ahhhhh, dont leave us. Ok, ok, so when I pulled my turbo, I replaced all the wastegate lines, so no, I have never experienced boost spike. So the point goes to you. Whatever you do, please don't leave us though!!! JK, go home already, your correct about checking the lines first.
Old 05-03-05, 12:30 AM
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Exclamation

Originally Posted by slpin
*sigh*
except boost spike happens at the beginning of the boost
while creep happens in high gear, and goes up slowly
you do not even know the difference between them
the problem in his case... is most likely a leaking vacuum hose that goes into the wastegate

remember.... he has a 89... that brittle vacuum line has 16 years for it to crack and leak...

see.... this is seriously a pathetic forum.... with the exception of a few intelligent members, the rest are just followers, saying the same thing over and over again....

from people who thinks they know everything and couldnt even type... to well... people who just follow everyone else and say the same thing over and over....

how would porting the wastegate help when the wastegate isnt even opening at the beginning of the boost...

lets weight something out, ok? port the wastegate, drop exhaust, take turbo out, port it, REUSE his old compressor to wastegate vacuum line... STILL spike....

or just replace the vacuum line, and NOT have it spike....

go ahead... waste your time... be ignorant....

this place sucks... im going home
^^Yup hes correct. This same problem happened to me with boost spike & I thought a mbc would work & control it & for some stupid reason, I decided to post on this forum for help & everyone that posted told me to port the wastegate & when I went to my mechanic, I told him my problem, & told him what ppl posted, & then he called me a stupid *** & told me "if you want me fix the boost spike, I'll I have to do is change the vac hoses that go into the wastegate, but if you want me to rape your pockets & take your weekly check from work, I'll port the wastegate for no reason."

So just check your vac lines.
Old 05-03-05, 01:20 AM
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Make sure the line that goes to your WG is short as you can make it.

Also, you could try putting a restrictor pill inside the wastegate vac line.

I am trying to think what would cause spike. So, you floor it and it jumps to 15psi. then drops back to a controable 10psi.

That really sounds like a vacuum line problem. Make the line as short as possible. Also, take the line and run it staright from the compressor housing to the WG actuator and see what that does.

I would guess the reason it spikes is because your WG gets temporally over whelmed by the rapid exhaust flow. So, try that restrictor pill.

James
Old 05-03-05, 02:37 PM
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Wastegate... wastegate... wastegate...

BTW S4, or S5?
Old 05-05-05, 01:20 AM
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thanx for all your help guys, thanx especially too slipn, i'll do those asap, it's an S5 by the way....
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