i'll do a search tomorrow, but it's late, hoping a rotor head can quickly answer my question. got a apex boost gauage put on last week. did some wot runs today in 4th gear. noticed boost went up to 12 psi, almost 13psi. most of the time it would be a little over 10psi, then when i floor it it goes to 12psi. have a hks downpipe and n1 dual catback. stock ecu. should i be worried? is this what you guys refer to boost spike? or is this normal with dp and cb. much thanks.

 

yes u should be owrried, the stock ecu is sopposed to cut fuel at about 11.5 psi. your boost gauge either doesnt work right or you already have an aftermarket ecu or a chipped one. and if not then you better be worried

 

i'm 99.9% sure it's stock ecu. the previous own, sole owner, kept it 100% stock. assuming the guage is correct and i was reading it right (it's late, little tired, maybe read it wrong ) has anybody heard of a dp and cb causing 12-13 psi? i keep reading that with dp and cb i should be okay with stock ecu. wtf

 

you should be ok but everycar is differnt. on this forum it goes that 3 mods then u need ecu. if you call m2 they will tell you that after just a downpipe u need an ecu.

 

be worried, but at the same time know that it happens to many. i installed an HKS DP first and got high readings. i as getting about what you were then i added an apex intake. didnt help out any. im getting almost 12-13 psi a lot, but i am still waiting on my PFC. till then im being as safe as possible, and getting sick of 100 octane(well just the price). of course i could just take the mods off, but what fun is that
kris

 

just be careful in 4th gear ttb. Don't floor it when it's in fourth...just downshift.

 

thanks for everybody's input. well, at least if the engine blows it's a 100k mile engine so i wouldn't feel that bad...

 

100k, you are pushing it! Supposedly the i/c is only big enough for you to run 12psi so be very careful in hot weather.

 

yea, i'm surprised the engine is still "strong" after 100k miles. but the previous owner took pretty good care of it and didn't drive it hard. it'd be pretty funny if i blow the engine in 3 months after he had it for 8 years actually it wouldn't be...

 

I'd start saving for a new motor
wait a minute...

 

ttb:

I recently got an RB dual-tip, so I have cat-back and a downpipe as well. I still don't have a full time boost gauge as I'm still waiting on Omori to come out with their custom gauges for the FD. I bought a $20 gauge at the parts store but it is only scaled up to 10 psi. I hooked it up and went driving today for a test and I'm easily hitting 11 or more in 4th and 5th at low rpm. Actually, it's scary how easily you hit 10+psi cruising in 5th.

Anyways, from what I can tell from the gauge, I'm getting an 11-9-11 falling to 9 or 10 boost pattern in 3rd gear. I'm not hitting fuel-cut at all, but I worry about when the weather gets colder....

Anyways, here is the chart for fuel-cut, you will notice that it varies by rpm. I think both of us are ok, as long as you are not exceeding 11 psi at high rpm or spiking at the transition.

RPM ABS. CUT OFF(PSI) SEA LEVEL CUT OFF(PSI)

1000 26.5 11.8
1500 26.5 11.8
2000 26.5 11.8
2500 26.5 11.8
3000 26.9 12.2
3500 27.1 12.4
4000 27.5 12.8
4500 28.0 13.3
5000 26.9 12.2
5500 26.0 11.3
6000 25.8 11.1
6500 25.4 10.7
7000 25.4 10.7

 

You just need to adjust your wastegate and prectonrol pills or put manual bleeder valves in place. Then adjust so you don't get quite as much boost on the primary turbo. No big deal. Even 12psi on the primary is nothing to worry about really.

Wade

 

his engine does have over 100k on it, even if he doesnt overboost it, it probably wont live much longer

mike

 

Similar mods here. HKS DP, Borla CB, RB intake duct, stock ECU.
GReddy Profec-b boost controller solved the 12psi+ and spike problem.

 

yup, 100k original engine club. i think ivan is just waiting for me to call him and tell him i need a rebuild

 

yup, i know he told you not to mod it too much before it goes too.

mike

 

mines SPIKE up to about 11.5 - 12 sometimes....but it stays around 10. all i have is an intake

 

before rick put the highflow cat, dp and cat back on my car I got like 8 8 8 boost pattern. After I got 10 psi in first 8 transition and it went to 12 at 4500 rpm, so rick eased off the gas, told me not to engage the 2nd turbo till I got my power fc.

Becareful. I get concerned with 13 PSI even with the power FC

 

what exactly happens with fuel cut off? does the car just die or just the engine go kaboom!!!!