Trebor69

Hello All

I am running a MY93 WRX with following mods

VF34 Turbo - New
HKS FMIC
HKS Downpipe and decat 3" system
HKS Powerflow Air intake
Updated Fuel Pump
Z4 ECU
Forge Atmos Dump Valve
Dawes Device at 1.1bar
HKS boost Gauge

Running 285BHP with 250lb Torque

Recently I have driven a few other Impreza's and realsie my car is quite laggy..

My car builds boost from 2500rpm but doesnt really go until 4k ish. if I boot it doing 4,500rpm+ it gets back on power quickly.

When accelerating from 2000 rpm I get a whooshing noise, not a leak or anything bad, but I consider it to be filling up the FMIC and piping.

If I removed the FMIC and fitted a STI top mount would this seriously remove my lag as it doesn't have to fill up FMIC?

Also what power loss would I expect going back to topmount?

I am not considering modding this car any further, I am driving for a year then will be buying a newer one

Also what kinda characteristics does a VF34 have.. I do have a TD05 sitting in garage. Maybe fit that and sell 2 month old VF34??? Anyone?

Why are FMIC fitted anyway, Better cooling I know especially in summer months, but what are benifits/drawbacks?

You info/ideas in depth will be appreciated

Cheers
Rob White

Franko

Changing to a top mount won't get rid of much lag if any at all..
I changed from a top mount to a FMIC and havn't had any noticable lag..

The FMIC will provide a cool air charge and with an aftermarket ecu/remap extra power can be had..

You will notice a difference in power when changing back to a top mount how much that is depends on how good your ecu is at running the car with the cold air charge..

I do not know the characteristics of a VF34 but changing the turbo to a smaller one will most deffinetly have less lag..

Changing the Atmospheric dump valve to a recirce valve will help performance too..

Trebor69

Cheers Franko

So FMIC to topmount not much diffo in lag, Well best i keep FMIC on then!!

Regarding the VF34, I was advised to fit this turbi, I am wondering if the choice was incorrect??

Running my spec and not doing any more mods, was the VF34 a bad choice??

Rob

alanbell

iTrader: (6)

Ive got a tdo5 on mine 96uk over350bhp and its gooood BUT Andy F 5 / 6 turbo is better than mine >> at the mo ???? Alan.

97 rExy

Running similar mods on my97(fmi,motec,3" ,VF34,silicon intake,etc).
While car was running the TD04L with above mods did some tests and then with VF34 at the same boost levels(1.15bar).
Driving in 4th gear at 2000rpm and then floor it:
TD04L full boost at 2800-2900rpm
VF34 full boost at 3100-3200rpm

Bob_Baker

Looks like you havent remapped it yet.

Decent remap will make it a lot less laggy.