log1

hi all, i need some help, i have 01 wrx with some mods on, and in the future i intend to run the car at 450bhp with all right mods. what is the good route to go? also i hear the cold start and ideling on the gems can be a right pig. any help!

Bob Rawle

Once you have decided on the engine you are going to use you can then look into the ecu's available, the oem ecu will support 450 no bother with an uprated engine and associated mods.

best regards

bob

log1

will the maf be a problem?

360ste

iTrader: (1)

Cold starting with the GEMS can be a pain if not done right. I've got GEMS on my 02 STi and being in the higlands (ish) of Scotland winter can be entertaining first thing in the morning. If there is going to be a very cold morning I pop into work and spen a short while swapping the ECU over so I can get it started in the morning. Last winter had to tow my car into work due to partial flooding and flat battery. Just my luck heating had packed in so had to take plugs out to dry beforte start up. But when the car is up and running what fun. Decide what you want to do with your car then speak to people in the know, I found best way was to get a sheet of paper for each option and then write pro's and con's. Good luck m8
GEMS uses a MAP sensor by the way.

Bob Rawle

Nope maf would be fine, using a decent size maf tube and a rescale no problem.

bob

steve rally

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SPEN555

Steve,

Is the 2.5 engine the std bottom end or has it uprated internals?

Cool torque figure BTW.

s5ooob

iTrader: (1)

Steve has recently fitted and mapped Gems on my v5 type R. The result is a car that feels every bit as smooth and well mannered as it did with the o.e. ecu, proberly moreso, but now with a real serious increase in performance over standard. I've no starting issues at present,though it's not that cold out just now, but should that alter I've no doubt steve will,as promised, resolve any future problem in that respect.

steve rally

We achieved better (more repeatable) boost control with the GEMS.Also the "in gear" control was better.

MR400

Very surprised with this Steve; in gear boost AND wastegate compensation (amongst other boost control maps) within the factory ECU ensure excellent boost control. Any boost issues I've encountered have been mechanically caused rather than the ECU's inability to cope.

Another point I'm generally interested in is how the map resolution differs between the factory MAF based system and Gems MAP based system and how this leads to better spark control ?

msko

GEMS With MAP based set up, need to relocate IAT sensor to I/C(if topmount), For more accurate reading. Right?
So, the MAF sensor actually eliminates itself??

Scoobyslammed

The IAT sensor... so if you go for a FMIC... was I right in fitting my sensor as near to the T/B as possible in the FMIC pipework???

msko

Yes, you are right!

Scoobyslammed

Just out of interest... what would be the symtoms of a fault IAT sensor???

Back onto the subject... I run GEMS on MY98 STi Type R... I have no cold start issues what so ever...it idles spot on around the 800rpm mark...
If GEMS is mapped correctley it should be fine... My mapper ain't completely happy with Gems regarding the overall adjustability, as it could be better... but saying that... he's done a fine job of mapping mine so far... can't wait until its fully run in with my 800cc injectors fitted running 25psi and anti-lag going... lol

I think alot of the issues with Gems cold start wise is down to the amount of time the owner can leave the car with the mapper.... there in a rush for it back...
But you only get one cold start a day...