FAST & 160# injectors

[jbcalhoun]

I've searched and didn't find the answer I needed.

I am running a 2.3 ltr 4 cyl ford and have maxed out my 96# injectors. According the the fast they are running at 104%. And yes, I am making in excess of 500hp.

I changed the 96's out for 160#'s and am having difficulties in getting this thing to run properly. It doesn't want anything to do with less than 3000 rpm. The af ratios look good when the idle drops lower, but it will eventually die. I have tried changing the operational parameters - injector pulse width and microsecond delay with no help.

This is the B2B system.

Does anyone have any thoughts or can give me a point where to start?

I am about ready to put back in the 96's and give it healthy dose of methanol to make up the difference. I am trying to get in the 10's and am really close. If I can get the traction issues solved, I am there! :biggrin:

Thanks for any help.

Brad Calhoun

 

[norbs]

Its my guess the B2B, can't control those injectors at that pulse width at idle. Upgrade the box to SEFI or do your methanol thing. Buy the kit from razor, as its well designed. What is the pulse width at idle with the 96's?

 

[jbcalhoun]

With the 96's the pulse width is 1.2. I tried 1.0 (didn't help) and can't get fast to allow anything under 1.0. Guess that is the low default.

Brad Calhoun

 

[TurboTR]

Two things- One, set your static fuel pressure lower to reduce the effective inj size. You might go as low as 30 psi static. This would reduce the effective inj size down to about 0.83 x 160 = 130 lb/hr, probably much closer to what you need. You would put in an inj constant of ~ 130 in the sw instead of 155-160. If you go to 35 psi static fuel pressure use ~ 143.

If you go to 130's, you have enough fuel for about 866 hp max at 100% duty, assuming a conservative BSFC of 0.60. 780 hp at 90% duty.

Next, change your inj opening time to something less, like say 0.8 ms. Even though this may not be the "real" number for inj response time, this will allow the system to command less than 1.2 ms or whatever inj pw it's currently flatlining at. This should help it alot. When all is said and done you may have to put up with some amount of over richness at idle, even when it's dialed back in with the 160's. When you are making big power it sux to not have alot of cyls (and injs). Once the VE is re-mapped and it's running well, don't tweak the fuel pressure and inj constant.

My own car suffers some from the same issues with 160's.

With the new inj the VE table will need to be re-mapped, along with the starting variables, accel enrichment, and anything esle that is in terms of inj pw, etc.

Alternatively (depending on your power goals) you could use the 96's and make them bigger by raising the fuel pressure significantly to get you back down below 100% duty (probably barely). This taxes your fuel pump alot more though and that all has to be considered.

Do you have the 9 sec SVO 4 cyl?

TurboTR

 

[jbcalhoun]

Thanks very much for the tips. I'll give it a go tomorrow and let ya know how it went. No this is not the 9 sec svo. That is Jon Dell Blair in Odessa. He has helped me out a bunch on this Project. Don't think I'll ever run a 9.2 like he did (he has the tall deck block with a few more cubes), but high 9's are in my future!

Thanks Again

Brad Calhoun

 

[norbs]

Those HP ratings are in Gross HP, not RWHP, so consider that in your calculations

 

[TurboTR]

Awesome Brad- good luck, and let us know if it works for you. PS- I know Jason (white Monte Carlo) pretty well

TurboTR

 

[Otto J]

What are you running for a fuel system? A pump and or clogged filter will cause you duty cycle to go off the board,At the nats this year my 96s were maxed out when my pump was going bad and my duty cycle was in the 110 range,Changed the pump and cleaned the filter and now i run in the 60% range,Which pump are you running?

 

[TurboTR]

Yeah, good point! Is the filter fresh?

TurboTR

 

[jbcalhoun]

Running the Aeromotive A1104 which not that old. Guess it could be going bad. What's a good way to check the pump. Fuel filter does need to be checked, I'll do that this morning. Thanks

Brad Calhoun

 

[Otto J]

Thats the eliminator pump,More than enough fue; pump,You can take your return line or feed line off and put it in a gallon container and make sure it pumps a gallon in a certain amount of time,IM not exactly sure what that pump will pump,Someone can do the math

 

[jbcalhoun]

KLHAMMETT - Checked the filter this morning, all is good there.

TURBOTR - Your tricks are working. Idle not an issue anymore, but man am I having to change the tables a bunch. Slowly getting there. Guess I'll see if it was worth the effort or not. If it isn't....methanol injection here we come!

Many thanks guys for all the help.

Brad Calhoun