SpecR1

I live in Canada, we get the same cars for most part as the folks down in the USA. I own a 2003 wrx. After installing an catless uppipe and downpipe. The car would spool around 2500rpm, I for one have always appreciated bottom end torque. I recently test drove the USDM 2.5L sti. The car was unbelievable to say the least, bottom end was phenomenol and top end was not too shabby as well. Shortly after, I was in debate to either drop in a ver 7 jdm sti motor/and tranny versus trading in for a 2.5L sti. I choose the ver7 jdm sti conversion, after picking up the car yesterday, I was very disappointed in the lack of bottom end. The car has a vf34 turbo, and really not a whole of action until 3500rpm. I plan to put in a catless downpipe and to help with earlier spool up, other than that, I'm not too sure if there is much more to do. How do you guys feel about the lack of bottom end on the ver7 sti? I assume you guys have the same motor as me for the most part.

joe

R19KET

Joe,

In effect, all you've done, is swap one 2.0lt, for another, and the VF34 is bigger than the TD04 on the WRX.

The STi internals will be stronger, and allow you to run more boost, but this won't help bottom end torque. This could be improved with mapping, or you could fit a VF35.

Have you done a full STi& conversion, including the VVT, or just the bottom end ?

I'd consider getting an EJ257 2.5lt short engine, and fitting the WRX heads, and sell the STi7 engine. That's the only way to get the bottom end torque.

Mark.

johnfelstead

dont agree with that last sentance mark. You can make noticable gains to bottom end torque with an ECUTEK remap.

Have a look at the torque curve on the PPP STi for an idea of how you can improve what you currently have via a remap. http://www.prodrive.com/uploads/03MY%20WRX%20PPP.pdf

SpecR1

Hi Mark, I've done a complete motor swap with modified wiring. I am supposedly equipped with AVCS. btw, I am dissappointed with the bottom end, however, the sti motor is significantly more refine. The engine is much quieter and very smooth while idling, and it starts up with less effort. On the otherhand, the 6 speed gearbox is a whole other story, worth every penny. Before the swap I read good things about the ver7 motor, some claim it pulls much smarter from 1500-2000rpm on. This was a comparison to my non AVCS wrx motor. I was also told the ver7 can give the 2.5litre a run in the top end, but after driving both cars, I doubt that claim also.

joe