Fast XFI ,Power plate in or out wth Alky ?

[gczarny]

here is my question , based on RJC flow chart for 70mm upper plenum is there a model of individual cylinder correction % you could apply with Fast XFI instead of using powe plate and be safe ? I know that without EGT probes you may not know what's going on for sure but if we know bench flow test results could somebody figure out how much fuel is needed to compansate ? I blew HG on #3 with power plate installed so I am thinking about taking it off also ..... is it different if you use Alky or Not with power plate ???? somebody said that if you using Alky your rear cylinders that are known to get to much air now they getting more Alky then the rest ??? makes sense ,what do you think ?

 

[Razor]

To make sequential adjustment to fuel, you need data.

Alky wont distribute unevenly when misted out of a nozzle. If that where the case you'd be blowing out cyl 1 and 2.

#3 is the most common cylinder to go on a TR engine. Then its 1 and 2

I'd be looking at WOT AFR when it happened. Did you log the run?

 

[gczarny]

To make sequential adjustment to fuel, you need data.

Alky wont distribute unevenly when misted out of a nozzle. If that where the case you'd be blowing out cyl 1 and 2.

#3 is the most common cylinder to go on a TR engine. Then its 1 and 2

I'd be looking at WOT AFR when it happened. Did you log the run?

Hi Julio ,was going to call you about it and my leaking alky pump problem ,anyway AFR was 10.3-10.5 with your two nozzle system ,I run into trouble last fall without power plate I melted #6 piston ,that was with NO ALKY , I only fixed right side never pulled off left head so maybe this started back then ,maybe not , I put power plate on it and after 15 runs or so started to hear puffing sound ,it was compression leaking on #3 , gasket was burned through , Call told me to add 3% fuel with Fast on #3 and #6 , but I wonder if I should just pull power plate off when I am running alky ?

 

[Razor]

Gary,
you should be monitoring both alky and fuel since the computer you have has the capability.. and log those. In the event something goes wrong, you have your bread crumb trail to look at.

I've blow HG's with and without the plate racing the motor and getting greedy. So I cannot blame the PP for my own maladies. Its up to you to decide yes/no on the parts you use on the motor.

If your pump has a leak, it will not deliver proper volume into the motor. So get that fixed.

5 years ago I went through 3 head gaskets over a fueling issue. I thought it was the alky pump.. changed that.. boom went the second.. I thought it was the fuel pump, filter, rebuilt the FPR... boom went the third.. on that one I was datalogging fuel pressure on the XFI.. at 21 PSI fuel pressure dropped from 64 to 58.. and the XFI started adding fuel.. but too late.

The problem ended up being the stupid 30a Bosch relay used in the hot-wire kit contacts where burned.. so intermittantly it wasnt delivering full voltage to the fuel pump. Changed the relay, and HG.. never had a problem. So sometimes the stupid 2 dollar part gets you.

 

[bison]

here is my question , based on RJC flow chart for 70mm upper plenum is there a model of individual cylinder correction % you could apply with Fast XFI instead of using powe plate and be safe ? I know that without EGT probes you may not know what's going on for sure but if we know bench flow test results could somebody figure out how much fuel is needed to compansate ? I blew HG on #3 with power plate installed so I am thinking about taking it off also ..... is it different if you use Alky or Not with power plate ???? somebody said that if you using Alky your rear cylinders that are known to get to much air now they getting more Alky then the rest ??? makes sense ,what do you think ?

I ran with and without a plate on an iron headed 231ci engine up to 6000rpm with no difference at all in performance. I dont believe the statement that the rear cyls get a lot more air than the others. This may become true at higher than 6000rpm or larger than 231ci but i dont have any data with the plate over that rpm. I dont think its likely that the rears will lean out before the entire left bank will lean out based on the stock fuel sysem setup. But as you already stated without actual egt numbers you wont know for sure. When in doubt always increase plenum volume. That will slow the air flow through the plenum and help reduce pressure drop pulsations as the valves open and close. What hp level were you at when you hurt #3.

 

[bison]

I run into trouble last fall without power plate I melted #6 piston ,that was with NO ALKY , I only fixed right side never pulled off left head so maybe this started back then ,maybe not

If you melted a piston and didnt find an injector , injector driver, or inj harness problem id find it hard to believe you didnt compromise the left bank and probably a lot more. Id pull the engine and go over it to be sire your not overlooking anything else.

 

[gczarny]

If you melted a piston and didnt find an injector , injector driver, or inj harness problem id find it hard to believe you didnt compromise the left bank and probably a lot more. Id pull the engine and go over it to be sire your not overlooking anything else.

this was done to test limit of 93 octane ONLY , car did 11.01 at 124 MPH with 1.60 60' , I also was very low on fuel ( 5 GAL left on the gauge ) got some knock at last run and that was it , leak down test showed problem only on #6 cylinder so I fixed only that ,put about 15-20 high 10's to low 11's passes 127-131 MPH with alky and power plate fighting realy bad 60' times , 1.66 best a lot in 1.7-1.9 range ,that happend after I put relocation brackets on my axle and change tires/wheels to 15 " from GNX 16" , started to puff , pulled left head and only mid- thick layer of cometic gasket was still good ,the outter thin layers burned through ,since then I fatten my tune and drop timing 1 deg. just wonder if I should pull power plate or not ,egt's will go on soon ,I hope

 

[gczarny]

When in doubt always increase plenum volume. That will slow the air flow through the plenum and help reduce pressure drop pulsations as the valves open and close.

Brian ,what you mean by that ?

 

[gczarny]

Gary,
you should be monitoring both alky and fuel since the computer you have has the capability.. and log those. .

a lot of people told me to log FP , but how you log alky

 

[WSLN 6]

Same way. Transducer at the end of the fuel rail and wire into the XFI.

 

[gczarny]

you mean transducer in alky line ? who sells those for FP and alky then ?

 

[Razor]

you mean transducer in alky line ? who sells those for FP and alky then ?

I do. yes on alky line. There is a thread in the alky section. You should take care of the leak first tho.

 

[gczarny]

I do. yes on alky line. There is a thread in the alky section. You should take care of the leak first tho.

I will be calling you tomorrow ,ring ring ring ,thanks