Who makes the best adjustable FMU

[pullshard]

I have a non-adjustable vortech on my 2000 paxton car. Does anyone have experience with their sfmu or any other adjustable ones?
Thanks

 

[pullshard]

Anyone...

 

[CROM]

Cartech makes the best adjustable FMU's.

http://www.cartech.net/fmu2020.htm

The 2027 is probably what you are looking for.

 

[pullshard]

I saw that one as well. I was thinking of going between that one or this one: http://www.superchargersonline.com/product_detail.asp?PartNumber=V6X100-001

 

[kverges]

In today's world a FMU is like stone knives and bearskins. The biggest two problems are that FMUs bump fuel pressure linearly with boost, but fuel flow goes up as the square root of pressure, so you are either too rich at low boost or too lean at high boost. The other problem is that high fuel pressure is ******* injectors and fuel pumps.

What you really want is to adjust the computer for larger injector duty cycle under boost, which the VEC-2 and AEM can do. Yes, both are more expensive than a FMU, but both are a lot less than a damaged engine.

 

[pullshard]

I have to agree with you on that point. A chip-being one that replaces the stock one is the way to go. The aAEM is a great piece of electronics, but very pricey. The VEC2 seems to be the way to go price wise, but I would need to trailer my car somewhere to have it dialed in. That is unless someone knows of a tuner in northern Ca that can work on them. I have a RRFPR on a heavily modified turbo saab. It indeed has a flat spot where there is to much fuel being dumped, but past that mark it hauls ass. The ones mentioned above are not like the old fmu' where you had to remove spings and or diaphrams to get a certain amount fuel dumped in per psi of boost and that was it or all you could do. These look as if you can adjust at different boost levels. In other words it looks like you can set them to dump less fuel at certain points. I could be totally wrong, but it seems that way from what I have read???

 

[kverges]

TEh VEC2 should not require any trailering - you should be able to get a basic setup quickly to at least be able to trundle to a chassis dyno - I actually tune mine on the street with a WB02 meter

 

[formula1]

If you can afford it the AEM is a fantastic piece of equipment...I have one (not on a Viper) and the level of tuning you can do is incredible. The amount of datalogging you can do is just as impressive, really makes tuning into a science.