jstrunk

iTrader: (10)

Alright so ill try to get the VAC reading at idle if that helps but i just installed my Boost gauge.. mechanical STRi..

In second gear it looks like im hitting 15psi!... oh no!

in third it looks to have hit almost 13but then stay more towards the 11-12.5range...

Currently here are ALL my mods that i know of..

Downpipe
PFS Exhaust
Greddy IC Hard Pipes (3 piece)
Koyo Radiator
AST
Non Sequential Twins
Ported Wastegate
New VAC lines/Stainless oil lines
Samco Coolant hoses
Nippodenso Fuel Pump

I was expecting 1-2psi of boost above stock but 15psi!!! wow.... i think i should be concerned... should i?

dgeesaman

iTrader: (7)

Wow that is pretty high. Is the 15psi or 13psi for just a moment or is that a steady maximum? If it's real, it's dangerous.

In any case it sounds like your boost is rather irregular and that you need a boost controller. Then check the calibration of the gauge with a Mityvac or something else and set the boost where it should be.

smcginnis87

Yea i have about the same mods and my car made 15 and one time 17 so a friend un pulged something ( i couldn not tell you what) but he did and not its stays around 7 till i get my Power FC or a boost controller

but it is unsafe and can make your car go boom

jstrunk

iTrader: (10)

ill have to check to see if its just spiking to 15 but i'm pretty sure i saw it solid at 15 in second.. ill double check... next time im in the light (probably saturday)... it was in the night and i didn't wire up the lights.. so either i do that tonight and then make a run tonight or tomorrow night.

yeah i thought 15psi was a bit on the high side... Ill try to get it going tonight...

i tried linking it to the ashtray for light but it didnt seem to work...

Force13B

iTrader: (19)

i know what he unpluged you were running on strait spring pressure from your wastegate.

OP i would check your lines on your wastegate and turbo precontroler to make sure there are pills in the lines, esp on the wastegate. You can feel the pill in the line the pill looks like this

mrb63083

iTrader: (4)

Do you have a straight midpipe? That will cause boost spikes like crazy if you do.

You're safe up to the 12-13 area, but anything over that is dangerious on the stock fuel system and ecu. Additionally, if you're running more than 10psi you need to upgrade your intercooler as well.

jstrunk

iTrader: (10)

well its not a 100% stock fuel system since i have the Nippodenso Fuel Pump...

I don't have a mid pipe as well.

Ill check pills either tonight or tomorrow. cant see hte picture at work so ill have to wait till i get home regardless. haha.

I don't want boom boom!

gracer7-rx7

iTrader: (16)

What ECU are you using?

What are you using for boost control?

Missing pills will usually restrict boost to 7 PSI.

jstrunk

iTrader: (10)

Stock... boost control? haha what boost control. No but seriously just the ported wastegate...

the only thing "mechanically" done are the list in the first post. - still at work...-

Force13B

iTrader: (19)

I had 1 ripped line on my wastegate line and it causesd high boost then boost wouldn't build at all and the exhaust would get louder.

gracer7-rx7

iTrader: (16)

I'm assuming you mean that the exhaust manifold was ported in the area that goes to the wastegate. As far as I know, you don't actually port the wastegate itself.

I didn't know you could even run NON-Sequential on the stock ECU but then again I know very little about NON-Seq so...

If you are on the stock ECU, I would be very careful driving the car at this point. You don't want to hit 15 PSI too many times on stockish fuel system and stock ECU. You are playing Russian roulette with the life of your motor.

I suggest you start with by installing a boost controller - manual or electonic. This will give you a means to control boost while/if you keep troubleshooting the system. It will provide you with a safety margin as well. Boost control issues can be caused by lots of different things - bad/old/crispy wiring harness, bad solenoids, bad vac lines etc. Plenty of threads on that topic so I won't comment on that.

dgeesaman

iTrader: (7)

To make it safe you can unplug the wastegate and precontrol solenoids. This will limit you to wastegate spring pressure (8psi).

15psi is not a little high, it's too high.

Dave

chiribuki

And if I have 15psi of boost with one mapped ECU to this turbo boost? I need modify the fuel system and other, isn't it?

Force13B

iTrader: (19)

The stock ecu is not suited for anything over 10psi in my opinion. If you are upping your boost, (with a programable ECU of whatever kind) it is a very good idea to upgrade your fuel system as well. Running your injectors and fuel pump at max capacity will burn them out quick.

djseven

iTrader: (56)

Make sure you have the pill REMOVED for the wastegate. If the pill is removed and you are getting this high amount of boost pressure that means there is an issue with the wastegate, either the vacuum line is disconnected, ripped, or something is wrong with the wastegate.

sevensix

iTrader: (1)

faulty gauge?

fendamonky

iTrader: (6)

If you have mapped an ECU to run 15psi (1.05 bar, ish) than you will really want to upgrade your fuel pump and secondary injectors (at the very least).

With an Apexi Power Fuel Computer (PFC) I was seeing 100% Injector Duty Cycle(IDC) on the stock fuel system (Stock pump, 550cc/850cc injectors) at 13psi before my mapping/fuel upgrades (Bosch 044 pump, 850/850@50psi base fuel pressure: now showing 85% IDC at 1.3bar). Anything over 85% IDC is not safe for an extended period of time.



For the OP:

I was under the impression that you would have hit fuel cut WELL before 15psi if you were/are running the Stock ECU. Have you recently purchased the vehicle? If so, were the mods you listed already on the vehicle when you bought it?

I would (visually) inspect the ECU to confirm whether or not it's stock (the stock one should not allow boost that high) before going further.

If worse comes to worse... you can always take the clamp off a boost hose to intentionally create a large boost leak, thus limiting the pressure seen in your engine until you can get the problem (15psi on the stock ECU is a BIG problem!!) fixed.

Intentionally causing a boost leak will not make your FD fun/enjoyable to drive at the time (at all), however it will keep your engine together long enough to figure out, and fix, the problem.

Best of luck!

jstrunk

iTrader: (10)

Thanks for all the concern, Ill look to see if a stock ecu however im pretty sure that it is. I did buy it with the Cat-Back and Downpipe and then i had the previous owner who rebuilt it for me install the other things on the list while he was rebuilding.

Once i get some light out ill look into what all of you are recommending.. i might just end up getting a boost controller.

we'll see! Thanks again! ill let you guys know what i find!

DaveW

There is a delay built in to the stock ECU's response (fuel cut) to overboost, so the likelyhood of getting fuel cut in 1st & 2nd gear is low, because it happens so quickly.

Dave