Looking to ditch FMU, suggestions?

get some 42s and have it tuned, you wont need the FMU then, thats what i am fixing to do.

btw do you have any times or power numbers, your combo is similar to mine. got any pics/vids?

and how much boost are your running what specific blower are you running.

i run the V1 SC trim blower. it made 5 psi out of the box on my engine ( thumpers, typhoon and b-cam) but i ran it at 9 psi for a while

i have since gone to an f-cam and got bigger valve put in my thumpers.

i ran 19s with the FMU making 9 psi, it ran alright. but it being untuned... blew a HG at the track. no wideband or anything i was in the dark.

i also ran the car with 42s (untuned and NO FMU) and it ran and drove ok but seemed to run rich and i lost alot of power. i mean a huge loss of power. the car ran better at 5 psi with the FMU than it did running 9 psi with 42s with no tune.

got my car back together with the new goodies and am running the 42s with no FMU ( i plan to tune it with a tweecer) and it runs pretty bad, it will run and drive but it just isnt right. it acts rich but my WB shows dead lean so i may be burning excess fuel in the headers i duno.

but getting the car tuned will cure all that. with a good tune with 42s the car should drive and start like a new car and the AFR should be dead on at WOT etc etc. and should pick up some power.

i WOULD NOT run the stock 19s with no FMU, the stock injectors alone will not be able to feed your combo with the blower and you could detroy your engine.

i also wouldnt reccomend running the 42s with no tune, it will run worse. but get it tuned and it should run great. and you cant really "oversize" an injector. with a proper tune you can make 42s work perfect for even a bone stock engine that will never use that amount of fuel. 42s with a mild HCI and blower is just about right. 42s will MOVE ALOT OF FUEL. if you plan on keeping it mild and not upgrading boost you can probably use 36s and be fine. but a bigger injector will give you some growing room if you ever decide to upgrade power/boost

i could see running HUGE injectors like 150lbers could be overkill. you would be running such low pulse widths it would really narrow down you tuning range and make it harder to tune if you get what i mean.

you will def. need bigger injectors, we run 30's with no FMU and a 255 in our stock longblock car. If you really want to get the FMU out of there you will need atleast need 30 to 36 pound injectors to start. If you plan on upgrades in the future don't even half-step get the lightning 42 kit and be done with it!

Either get the 42s and a tune or run the FMU with anything smaller.
It is always best to at least have your combo dynoed so you will know you are safe.
Whether you have them tune and chip it is up to you.

how much boost are you running? i would also invest in a wideband. a very useful tool. one slip up on a blown car could spell disaster. a blower engine isnt as forgiving as a N/A one.

1993SSP said:

I just found out I can get by with 30's, spoke with the guy at the dyno shop and he told me I would be good to go with those

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Ask him what size do you need if you ever decide to up the boost.
I know this has about a slim to none chance of happening.

Good luck!

30's will let you squeek by with a little regulator and timing tuning

1993SSP said:

Do you guys think the 30's would work for me?? I have found a deal on a set, Id much rather buy these and spend $100 bucks getting my MAF reprogrammed. Would definitely be easier on the wallet

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If you are getting a 'custom tune' chip via the J3 port, then there is absolutely NO need to re-cal the MAF meter.
Swapping out injectors can be done in the ecu...

Personally,
I would get the larger injectors... yes, you can do things to make them ACT bigger, but that isn't what I would do with MY car...

The purchase of a WB O2 sensor was suggested. If you are going to do the tuning yourself, then a WB is a sound investment. If you are going to leave all the tuning responsibilites to the dyno shop, then there is no need to spend the money on your own wb....


What it comes down to,
is that the custom J3 chip opens up some possibilities that don't exist otherwise....

just how I look at things,
jason