Drag racing my 2001 Proton (also: VX weight)

[EVO]

Krazy Kool!! Looked like a lot of fun!! Thanks for sharing! -Vince

[WormGod]

No engine mapping for for the blower. The ISUZU ECU is not coded to ... well... be coded, heh. I believe some folks have attempted in the past, and even when they managed to, it always managed to revert learn/reflash on it's next ignite. Sure would hate to spend $600 of dyno time for a protune just to turn around and have it flash again when you left. In any case, the ISUZU ECU "adapts" on it's own. I have never thrown any CELs related to air intake or manifold pressure/vacuum. The only real difference is actually seeing BOOST from my boost gauge.

Aside from the blower, it is just coexisting with bolt-ons, like a larger air intake (though I have the stock airbox back on currently since I use that in the winter).

And nope, no runs as is. With these big old 285/60 tires, there is so much launch drag that it would do no better than without a blower. The only real advantage I have ever had with being boosted is at highway speed. Passing at 55+ is a breeze. Once those big meaty tires are already turning, that's where a blown VX shines.

[EVO]

Just out of curiousity whats are you getting mpg with that blower on? Good to know that the supercharger mod does not throw codes!! I'm getting around 15-17mpg stockish driving Ms. Daisy style and 12-14mpg lead foot style!

[Leon R]

Gary,

Something has to be compensating for the boost pressure! Even if it is as simple as a fuel pressure regulator that can raise fuel pressure when it sees boost, but something has to change .

Do you recall if you had to upgrade your FPR? What boost are you seeing? What about your fuel pump, is it still stock?

[WormGod]

MPG is worse, but that's mostly tire related. Should technically be able to get better MPG with a blower and driving "responsibly", but no. I am never responsible when I drive the VX and with the tires, I get around 11-13 MPG.

The boost pressure line essentially taps from the fuel/manifold pressure. Stock FPR. Stock fuel pump. I believe another VX'er, Cyrk, had upgraded his fuel system when he supercharged, but I can't recall what all he did.

Remember, the Alpine is a baby blower. Nothing to call home to mom about. With the 5lb pulley, the max boost I have ever seen in 6psi. BUT.... that's instant boost with NO lag. I'll take it!

[EVO]

No Turbo Lag is a ++!! No drivechain problems with the added boost? On my EVO the first thing to let go was the transfer case, grenaded on launch when I hamfisted the clutch! But that was with 30pds of boost and drag radials! What a mess that was!! LOL! I can laugh now, but I was ****ting a brick when it happened!

[Leon R]

I looked over the factory fuel system and I think I understand what is happening here: even through, stock FPR is meant to work off vacuum, this type of FPR is capable of using boost to actually increase the fuel pressure! It isn't necessary designed to do this, but it can do an OK, be it not very reliable, job at it.

I guess being at only 5-6 psi, keeps it "safe enough".

This is all coming together... I might have to start a Rear Mounted turbo thread

[WormGod]

Right enough. The fuel is injected under pressure and the pressure determines the dump. It is not ideal on the VX with the blower, but it does work well enough. On heavy drops, I will catch a whiff of some fuel but never anything to worry about. I think a different pulley or higher vacuum blower, and you would get enough fuel dump to cause worry.

Ideally, you would want to consider a more economic system. Larger injectors, actuating fuel rails and pump, etc.

But, for a Sunday car for me, it's well enough now. Besides, there is nothing like going WOT on the merge lane on a highway and hearing that jet plane "whirring" sound from the blower and intake. The VX gets attention as is, but when it sounds like THAT.... oh yeah....

[EVO]

AMEN!!! To the Boost Gods for allowing us change all that is around us!! We give thanks for E85, 1450cc Injectors, Dual Inline Walpro's, and The Tuners that keep us on the path of enlightenment!! LOL!!

[Leon R]

So, just for fun, I used good old "Horsepower Calculators":

ET method:
hp = weight / (ET / 5.825)^3

Trap speed method:
hp = weight * (speed / 234)^3

My results were 169.3hp and 169.6hp respectively!

Giving 25% drivetrain losses, we get 212hp "at the crank", so everything seems in the "proper ballpark"!

I just might throw it on the dyno, if I can catch a cheap Dyno Day with one of my car clubs.