More Mods I've Been Hearing/reading About

[Rikki]

Are these two mods suitable or recommended for the MR2 at all?

The GT4 fuel pump one is where you have the pump running at full power all the time instead of only when needed. The VSV one is to keep the VSV active at all times.

eg: http://www.st205.net/techinfo/VSV.htm

R.

[pizza boy]

I wouldnt personally do either. The VSV is only active in limiting boost when the car hasnt reached operational temprature and if the air temp outside is below 4degrees...a problem in winter but now its hardly going to matter as spring is almost upon us. Also the fuel pump mod I wouldnt personally bother with. Its limited for a reason and thats economy and efficiency. The gain is minimal if your car is stock but the disadvantage is way too great as your car would eat fuel like %$(.

[Dame]

I wouldn't bother with the fuel pump mod, though it shouldn't make the car burn more fuel, since the injectors (under the instruction of the ECU) are what ultimately control how much is fed into the cylinders, and fuel that doesn't make it returns to the tank down a return pipe (funnily enough :) ). However, it really isn't worth it, and if the pump packs in, it's a right sod to get to.

The VSV mod will only work if you have a Rev 1 or 2, since Rev 3's did away with the VSV. In principal, I think this is a good mod, since running with low boost in cold weather is a right PITA and the VSV is very touchy. However, my reccommended route for this is to fit a Unichip. Costs £550 mapped, but is the safest way to do this. In addition you'll get bags of extra power as the chip remaps the engine for higher boost etc.

[Rikki]

Cheers for the replies :)

R.

[KiwiMR2]

The GT4 fuel pump one is where you have the pump running at full power all the time instead of only when needed.

How does this effect the way the car runs?? From the factory when does it run at full power??

The VSV one is to keep the VSV active at all times.

I had to do this when I installed my Profec B DS EBC......with the bc installed and running WITH the vsv ENABLED the car would boost to well above the factory setting BUT THEN the vsv would kick in and bring it all the way back down to the lowest possible setting of 7 psi...after disabling it I boost to the required setting and stay there ;)

Cheers

KiwiMR2

[Dame]

How does this effect the way the car runs?? From the factory when does it run at full power??

Apparently, the pump speed is varied according to how fast you are driving etc. I can't see how having it run at full speed all the time would make a difference TBH, since the car will have been tuned to deliver a specific amount of fuel via the injectors at a given time. This would have been set to fall within the supply of petrol from the fuel tank, with a generous tolerance to ensure the engine always runs at peak efficiency.