who's running a 305 using the fmu? are you using the booster pump? how much boost? and what size are your injectors?

 

I originally did not install the extra pump and did notice that it did begin to go towards lean with 7 lbs of boost. I had two choices either put in the pump or go with larger injectors and computer that could compensate for boost. I chose the latter. I originally had 24 lb injectors in the car and upped them to 32lbers with the 7749 computer setup.

I preferred to have the computer contol boost fueling then relying on a ballpark fueling from the FMU. Also, I have a hi flow pump in my tank before I did any of this to begin with.

 

i have a walbro 255 but i'm not sure if it was the 307 or 340 model, i'm capable of burning my own chips, but i dont know enough i feel to start with the $58 code, i would like to eliminate the need for the fmu and program it myself, but i just dont know.

can i use 30# injectors with an fmu ok?

if i dont use an fmu will 30# be sufficient for a 305 with around 9-10#'s or should i go with 42# i just dont want it to affect driveability down low

 

The #30 will work fine, I would probably not recommend #42 you may get into idle issues with short pulse widths (depends on brand of injector) #30 will be all that you would need to feed a boosted 305.

With that being said, I am still working out quirks in the $58 swap.

If you want to use the fmu with 30#(and set the injectors size in the bin to #30) it will work, however you would still probably have to use the addtional pump to keep the pressure up when the FMU spikes the fuel pressure inder boost.

Another option that I had considered was using $8d (and no extra pump) and the FMU at the 100 KPA area increase the fuel so that you dont have any lean issues under boost.

I'm sure others will chime in with their thoughts.

 

i would like to learn how to do the programming under boost, the only concern i have is that i dont want to damage the engine or any components, i will run the inline pump, that's not a problem, so the inline pump and maybe ford 30lb injectors i could run the $58 code with a 2 bar map, i would like to hear others experiences with the $58 code and it's behavior

 

Do you have a wideband O2 sensor? If so it would definately be a good investment. This way you can see what is happening and datalogit.

For $199 you can directly input wb02 into your datalogs and know if you are lean or not.

http://www.innovatemotorsports.com/x...me.php?cat=253

Also,
If you are running 30lb injectors and $58 you would not need the extra pump.

 

thats all you need to use wideband? all i have now is a heated delco o2 sensor, so even if i dont have the walbro 340 i can use 30lb injectors with the $58 code?

if i can get the car to run and it's a matter of working bugs and tuning out of the code that would be cool, and i can save money by not getting the inline pump and fmu and put that towards the wideband o2, anyone else have good info? thanks novass!!

 

You will have to find the patch for the $58 code and connect the input to the correct wire on the ecm. IF you search you will find the info. When I tune I use open loop and use the wb as my feed back for rich lean tuning. After I am tuned I re implement closed loop..





Yup. As long as the pump in the tank is in good shape and flows well.

 

That is the setup I am currently building. Stock 305ci TPI with stock GM fuel pump (60K miles on it) with new Ford 30#/hr injectors. The ECM will be a 730 MAP with the Syclone BBZB $58 code in it. I welded in an extra 18MM fittings on each exhaust pipe for the WBO2 sensor. The plan is to run up to 7psi of boost with an intercooler. Stock TPI compression is 9.5:1 for this engine and I plan to make a max of 300-350HP.

Yeah, you save on the FMU, but eight 30#/hr injectors will cost between $50 to $350 depending on what you buy. If you like messing with PROM tuning then go the $58 code route. If you don't, then go the stock ECM route with an FMU. Both methods can give good results.

 

well a supercharger just came in the works, i wasnt planning on getting one, was gonna tune $8d on the 7730, so i bought 19lb injectors (swapped the tpi in) but now i'm told to run 9-10lbs the injectors should be upgraded, then i'm thinking if i run $8d, 30# injectors and the fmu i really cant do much tuning anyways can i? procharger recommends stock programming, so i might as well go the $58 code route

 

I picked up brand new #32 lb injectors from Racetronix for about $29 a piece

 

just ordered some ford racing 30lb/hr injectors, will install new o rings, and use the retaining clips.

novass i'm most likely going to convert my existing 7730 setup over to the $58 code....i mean what harm can it do, it's just a few wires so i'm sure i'll have a lot more questions, which is why i'm here and support thirdgen.org!!

i checked out your website also, great job on the car!