will a 12-1 fmu be ok for 6pounds of boost? - Boost Forum

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will a 12-1 fmu be ok for 6pounds of boost?
Wednesday, May 29, 2013 10:39 PM
i have a fmu that is12-1 (2.70 inchs disk)would it be safe (or to much)to run my supercharger at 6 pounds of boost with my stock inj(99 cavi 2.4)?

Re: will a 12-1 fmu be ok for 6pounds of boost?
Thursday, May 30, 2013 7:37 AM
Way too much by a mile...

What you really need is an adjustable rising rate FMU, like the BEGI one.

Oh wait I happen to have a polished one for sale...

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: will a 12-1 fmu be ok for 6pounds of boost?
Saturday, June 01, 2013 11:58 AM
I also have one for sale lol


2004 Cavalier Sedan
Re: will a 12-1 fmu be ok for 6pounds of boost?
Saturday, June 01, 2013 12:29 PM
And I have a CarTech one for sale... fully adjustable.



Re: will a 12-1 fmu be ok for 6pounds of boost?
Sunday, July 21, 2013 10:32 PM
Why dont these fmu's go on sale when i need one haha....
Re: will a 12-1 fmu be ok for 6pounds of boost?
Monday, July 22, 2013 7:45 AM
ecotecnik wrote:

Why dont these fmu's go on sale when i need one haha....


Mine is still for sale.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: will a 12-1 fmu be ok for 6pounds of boost?
Monday, July 22, 2013 7:50 PM
Pm me a price
Re: will a 12-1 fmu be ok for 6pounds of boost?
Tuesday, July 23, 2013 9:47 AM
besides being able to electronically dial in the fueling what benefit is a 2 bar setup over doing a rising rate FMU, anyway?



RIP silver car. You will be missed.
Re: will a 12-1 fmu be ok for 6pounds of boost?
Tuesday, July 23, 2013 10:43 AM
No this will not work, you need to tune it.
Re: will a 12-1 fmu be ok for 6pounds of boost?
Tuesday, July 23, 2013 12:06 PM
Brad - a 2 bar map sensor on its own will allow you to electronically deal with both fuel and spark - spark being the more important of the two.

A FMU works fine for dialing in fuel under boost - much like a carburetor it's crude and inaccurate but it works... it just won't do squat for timing.

-Chris-




-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: will a 12-1 fmu be ok for 6pounds of boost?
Tuesday, July 23, 2013 10:48 PM
ok but why cant you tune the timing down? i just did this (well i added) to mine, i added 2* from 4000-6500rpm but you could sit there and screw with all kinds of settings for timing under rpm.



RIP silver car. You will be missed.

Re: will a 12-1 fmu be ok for 6pounds of boost?
Wednesday, July 24, 2013 8:18 AM
He's asking about using a rising rate FMU to add fuel. It can't touch timing, Brad. lol.

Also be careful with the timing you add (a bit late to give you the advice now but...) - when I dyno tuned a LD9 GMSC last year 1 degree of timing added was the difference between 198 whp and 206 wtq and 209 whp and 202 wtq. I kid you not.

(Meaning I added a degree of timing and lost HP but gained torque which the owner didn't want so I put it back down 1 degree and re-dyno'd to the same previous results.)

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: will a 12-1 fmu be ok for 6pounds of boost?
Wednesday, July 24, 2013 12:20 PM
SweetnessGT wrote:

He's asking about using a rising rate FMU to add fuel. It can't touch timing, Brad. lol.

Also be careful with the timing you add (a bit late to give you the advice now but...) - when I dyno tuned a LD9 GMSC last year 1 degree of timing added was the difference between 198 whp and 206 wtq and 209 whp and 202 wtq. I kid you not.

(Meaning I added a degree of timing and lost HP but gained torque which the owner didn't want so I put it back down 1 degree and re-dyno'd to the same previous results.)

-Chris-


lol i know im talking about using HPT to dial the timing in WITH the FMU. you said that timing is it's main downfall but if you tune for it, i dont see the problem? lol



RIP silver car. You will be missed.
Re: will a 12-1 fmu be ok for 6pounds of boost?
Wednesday, July 24, 2013 2:45 PM
-Z Yaaaa- wrote:

SweetnessGT wrote:

He's asking about using a rising rate FMU to add fuel. It can't touch timing, Brad. lol.

Also be careful with the timing you add (a bit late to give you the advice now but...) - when I dyno tuned a LD9 GMSC last year 1 degree of timing added was the difference between 198 whp and 206 wtq and 209 whp and 202 wtq. I kid you not.

(Meaning I added a degree of timing and lost HP but gained torque which the owner didn't want so I put it back down 1 degree and re-dyno'd to the same previous results.)

-Chris-


lol i know im talking about using HPT to dial the timing in WITH the FMU. you said that timing is it's main downfall but if you tune for it, i dont see the problem? lol


If you are going to tune your timing, why bother with the FMU in the first place?


- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
Re: will a 12-1 fmu be ok for 6pounds of boost?
Wednesday, July 24, 2013 5:39 PM
good question! lol... chris?



RIP silver car. You will be missed.
Re: will a 12-1 fmu be ok for 6pounds of boost?
Thursday, July 25, 2013 7:59 AM
Oedwards - some people like to use fuel pressure to add fuel rather than injector duty cycle. I did this back before I had other options and it worked fine, you just don't want to overdo it and stress the pump.

Rising rate fuel pressure regulators - as I said - are crude and tend to overfuel at low boost but they work.

Mine is for sale because I have found better means of tuning my car finally. I'd rather have far more control.

Remember - some people are very old school and dig using screwdrivers and turn screws to tune their cars... it's not awesome but it works.

Brad - when I say timing is the main downfall of an FMU I am assuming that somebody is installing one because they A) don't have HPT or B) don't know how to use HPT. Basically they are using the FMU as their tuning solution (as we all did in 2001... lol)

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
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