I was wondering this because with the cold weather we've been having my car will hit 21 psi on a regular basis and today I spiked at 23 psi. Normal boost is in between 19-20. Haven't experienced ANY fuel cut.

Current mods:

K&N cone
Mail in Dynoflash
Buschur D/P
resonated test pipe
3" CBE

Now I bought this car used....I know for sure it has/had some aftermarket parts on it. My "stock" clutch has lasted 30+ launches and 23k miles of abuse.

Any input is appreciated.

 

 

So you shell out money for the above mods but skimp out on a simple 80 dollar walbro pump..

 

It used to be you need a fuel pump right now. It's a little different now. There are guys running 115mph traps on the stock pump and stock injectors. Running 120mph on stock injectors and meth (meth is fuel though), it is only a 100$ mod max. it does add security.

I run 100 octane and 24psi tapering to 21 ish with a TBE and intake. Stock pump and injectors no knock at all.

 

Why pay $80 for a fuel pump if you don't need it ? Personally I think your just fine if it's just a quick spike no biggie .

 

I was just asking....I didn't mention I have a Walbro/MBC/o2 housing going on along with a custom tune by Dynoflash.

Just wanted some opinions.

 

Boost pressure is irrelevant unless you are using an FMU. Max hp and injector size is more relevant. There are people over here in JDM land pushing their EVO's to 330~380awhp with a stock pump. I would never do this because there are too many pumps availabe for a good price to chance losing an engine because of leanout/fuel starvation.

 

I've posted extensively in the past about this, but the short version is that the stock injectors flow enough for anything the stock turbo can flow, regardless of boost. Same applies to the pump, IF it is rewired.

 

If it is rewired???????????

 

Maybe because it's a cheap safty measure?

 

Kevin,

I second the Question..."IF it is rewired" ?

 

sorry for double-ish post...

I was under the impression (yes, by searching and validated/ ie wtaln VIII versus IX stg one) that the older cars' fp were weaker than the newer ones? ie first kit has walbro, second has no need of it?

 

The quick answer is that rewiring the fuel pump (see www.vfaq.com) increased the capacity of my pump (conditions: 11:1 AFR, pump gas, ~20 psi boost) from 34 lbs/min to over 42-43lbs/min of airflow (44 lbs/min mathematically, but can't verify that since the stock turbo could only do 42-43).

 

Thanks Kevin.

I checked out the site, found two "upgrades" for vr4's (I think) but no rewiring...
Just curious...Still looking for clarification

Tom

Sorry to OP, not trying to hijack, still thought it would help

 

You run a thicker gauge wire to the power source of the fuelpump straight from the battery with an inline fuse and a relay in place so that the pump recieves full battery voltage.

...like Kevin posted earlier..go to http://vfaq.com/index-main.html hit fuel, under fuel pump rewire click 2G FWD for a similar explanation.