FMU/FPR help - also missing link

[angela_itr]

Hi guys,

I've just had a Drag 3 turbo kit installed on my ITR, running RC 440cc injectors, a Walbro 255lph in-tank fuel pump, and Hondata s200 with stock internals. I'm looking to run 230-240hp initially.

The kit came with a boost dependant FMU fuel regulator - am I right in thinking this is no longer necessary with the Hondata, and should be removed? If so, do I need a replacement fuel pressure regulator or will the stock one be sufficient?

I've been getting confused with the difference between FMUs and FPRs, and which is good/bad If I need an FPR, can someone recommend a good one that comes with a gauge? I've seen the B&M ones but read that they aren't adjustable?

Also I've had a missing link fitted as it came with the kit. Again, should I remove this? I read something about problems with a missing link and Hondata but didn't really understand.

Sorry for all the questions just there's not many people in the UK who have gone the turbo route so its hard to get good advice.

Cheers
Angela

[DaX]

The S200B will replace the need for an FMU. An FMU is a "rising rate regulator." For instance, if you have a 12:1 FMU, for every psi of boost, the FMU adds 12psi of fuel pressure. When using Hondata, you need a 1:1 Fuel pressure reuglator. The stock regulator is 1:1 and should work fine up to a certain point, as it can become restrictive in higher horsepower applications. The B&M unit only modifies the stock FPR to allow it to become adjustable [so yes, the B&M is adjustable]. I currently have one. You can adjust the fuel pressure with it, but you can only increase fuel pressure above static fuel pressure...for instance if running a stock pump, you can't turn the fuel pressure down below about 38psi with the B&M unit. AEM makes one that is decent I think. IMHO, the best is Aeromotive. I know the Aeromotive FPR is fully adjustable.

Sell the missing link when you sell the FMU. The missing link fools the MAP sensor into not seeing boost [it's a one way valve...it only allows the MAP sensor to read vacuum]. Hondata requires that the MAP see boost, because now with Hondata, the ECU can interpret boost and adjust fuel and ignition accordingly.

[angela_itr]

Thanks Dax, things are a whole lot clearer now