if anything fails that is not due to you breaking it. like apex seal spring failure. oil seal failure. coolant seal failure etc

 

i have a haltech and i have a FJO wideband. my AFR doesn't go higher than 10.50 on boost up to 18psi. i have to check my duty cycle don't remember off the top of my head

 

car is at the judge's getting pettit chromoly axles, pettit drag launch kit and pettit trailing arms installed for sunday races. i should get the car back tomorrow. i'll look at it when i have time and tell you guys

 

If you have the (1) **** FPR, take note what your fuel pressure is at idle for me, would you? Thanks!

K

 

at idle i'm 99% sure its at 48psi. if you mess with the base pressure you are gonna richen or lean the ENTIRE range out..... just remember LOL

 

There is some inconsistent use of the terminology by vendors (and lots of inconsistent use in general) but I would like to see everyone agree on and use this terminology:

Adjustable FPR w/manifold reference (or just AFPR): regulator with one setting for base pressure with a 1:1 boost pressure rise for consistent effective fuel pressure at any boost level. Note that the reference does not give you "more" fuel under boost, it just makes sure you get the same amount of fuel delivered for a given duty cycle under any manifold pressure. Your effective fuel pressure is your fuel pressure gauge pressure minus your boost pressure. If you set the base pressure to 50 psi (with the manifold reference disconnected), your fuel pressure will drop under vacuum and go up under boost. It will always be the same pressure relative to the manifold pressure, so you get the same flow for a given duty cycle (the effective pressure will always be 50 psi).

Rising-rate FPR (RRFPR): regulator with a fixed or adjustable base pressure, where you can adjust the ratio of fuel pressure to manifold pressure. This will give you more fuel flow under boost for a given duty cycle as long as the rate is set above 1:1. Units without an adjustable base pressure are often used in conjunction with the stock regulator, so the RRFPR doesn't take over until the pressure it wants is higher than the pressure the other regulator wants. The rise rate is adjustable on al the ones I have seen. For a stock regulator with a base pressure of 37 psi, and a RRFPR with a base pressure of 30 psi and a 2:1 rise rate, you get this fuel pressure:
-15 inHg manifold, fp gauge 30 psi, effective pressre 37 psi (stock FPR in control)
0 psi manifold, fp gauge 37 psi, effective pressure 37 psi (stock FPR in control)
5 psi manifold, fp gauge 42 psi, effective pressure 37 psi (stock FPR in control)
10 psi manifold, fp gauge 50 psi, effecive pressure 40 psi (RRFPR in control)
15 psi manifold, fp gauge 60 psi, effective pressure 45 psi (RRFPR in control)

Note that an RRFPR gives you another adjustment point that you might not need with a programmable engine management system. I would rather just set the base pressure higher with an AFPR or get bigger injectors and do tuning than have to deal with setting the RRFPR and tuning. Simpler is better, and an AFPR and programmable engine management is enough tunability to do whatever you need to do. RRFPRs can be useful under specific circumstances, but I don't think a turbo car with a programmable engine management system is the right place to use one. They are often useful for putting a turbo on an NA car or for a little extra fuel with a piggy-back system and stock injectors. Remember that the fuel pump has to suppy the needed flow at the fp gauge pressure, which can get quite high with a RRFPR.

-Max

 

i think i have the AFPR. thanks for clearing that up max !!! i'll take pix tomorrow

 

More I think about it, Nocab, the more I think the RRFPR is too much trouble. Up the base fuel pressure 5psi.

 

can i use the factory 850 secondaries in my primary location? i have 1600 secondaries. i didnt know if there was a way to use the 850s.

 

i think you can allrotor. carson (spyfish007), who is missing in action according to everyone, uses 850's all around. i bought some extras from poweraxl( steve) and planned on using them in that configuration or just send them to rc for the upgrade

 

nocab - I have 2 x 720cc primaries and 2 x 1650cc secondaries. Base fuel pressure is 45psi. I have enough fuel for 30psi and 600+ at the back wheels. You should have left the 850s as 850s and not had them modified

 

I'm with you Tony! Gonna stay with the AFPR and turn the fuel pressure up...

AJC13B - I'm sure I can find someone who wants 1300's and will swap out their 850's for my 1300's... oh Carl, where are you?

K

 

Helloooo, think i just found my 1300,s! C.

 

I was going to try 1600cc primaries, but after talking to Koji at xs
I found that the 920cc I am using is the fastest injector pulswidth
the PFC can fire. With 920cc injectors my idle is minimum 1200rpms
due to injector pulswidth. I think Koji said that the PFC fastest pulse
width is 2.3ms, note: anything below 1200rpm IDLE SUCKS.

Xcesive Motorsports

 

Ralph, did you try the 1600cc's in the primaries, or are we going by with what XS is saying? I'm just asking cause I figure if the weaker injector drivers from people using Haltech are controlling 1600cc's in the primaries(a few of my friends have it setup like this), and it's working, why wouldn't it work with the PFC? Also, are the 920's that you are using high or low impedience injectors?

 

I didnt try the 1600cc because the 920s are barely good enough.
All my injectors are low impedence that I use. When I put the 920s in
and adjust the lag diff to max lean, reducing the basemap time lower
and lower made no diff. I adjusted the software to get the fastest time
per cell (To the best of my knowledge) and no diff in AFR. I have a dyno
and horiba wideband that I use for testing. My 1600cc injectors are also
low imp. so I figured why try anyfurther. By the way my car runs and Idles awsome with the 920s.
Xcessive

 

Thanks Rob, that's what I thought, I also will be using all low imp. injectors with my setup, guess I'll be going with 1000cc primaries and 1600 secondaries, only thing is what's the max RWHP with that setup at 40psi base fuel pressure?

 

I forgot to answer your question. Yes I think the limit is the PFC.
The 1600cc injectors should work with a faster injector driver like
the haltech etc. Now maybe I am missing something, I am open for
input. Ralph

 

What I meant to say is that my friends that use the 1600cc primaries in their cars with the Haltech the idle is like 1500rpm because of the injector size, I just thought the PFC would be a little better since the drivers are better, that's all I was asking, but I guess that neither can control injectors that big for this type of application at low idle. I do know that mostly everyone gets away with the 1000cc's in the primary with good idle, do you know the RWHP limit of that while using 1600cc's as secondaries at 40psi base fuel pressure?

 

Ill find out how much HP in approx a month. I am waiting on a tranny.
I am running a T72 Qtrim and am going to 30PSI so we will see
how much fuel is available. Thx Ralph

 

nocab,

Are you pushing 550 rwhp? You should be if you are running at 100% duty. Make sure your a:f's are correct and if so, make sure your fuel pressure is not dropping. I think the latter is likely.

Secondly... don't even think about 160lb primaries. I tried to run 4 850's in low load which is almost exactly the same flow as 160 lb primaries. Low speed drivability is horrible because you reach the lower limits of the injectors. Around 1.5ms is the shortest time they will come on and work properly. Even at 1.5ms you will have too much fuel. You can get around it by running 10:1 at low load but who wants to do that.

Bottom line, you should think about staying below 850cc for primaries if you want to play it safe... and verify your fuel pressure isn't dropping or something else isn't wrong - you shouldn't be running out of fuel with your setup.

Wade

 

Wade - I'm breaking the tires loose @ 90Mph in 3rd (255x35x18 Toyo Proxies, 5k miles on them). My Blitz powermeter shows 500rwhp+. I'm SURE Im pushing the limits of my Denso pump.

I run a Wideband in my car all the time. The Inj Duty cycles are likely high due to
1) too low a base fuel pressure (currently 45psi @ idle)
2) loosing fuel pressure up top, I don't have an in car-fuel pressure gauge and Tony (Badog) won't sit in my engine bay while I do a 3rd gear pull to watch the gauge. I plan to do an in car fuel pressure gauge soon.

It looks like I'll go for 850cc primaries, I think with trimming several people have had success with them.

Thanks for the advice and sharing your experiences!

k

PS lined up with a buddies SupraTT from a roll this weekend (420rwhp @ his last dyno). I pulled on him like he was sitting still... The quickest moving thing in his car seemed to be his jaw dropping...

 

I have 1300's and 950's in my car with pfc and everything seems fine.

 

OK guys a little update on the 1600cc primary injector subject, I spoke to some of my friends on the subject that have this setup and guess what?, their cars idle at 900RPM!!!!!, I stated about them idling higher before, but now I remember that it was when the car was cold, and it was in warmup mode. I also had a convo with a tuner that tunes their cars, and he told me that a 1600cc injector has a resistance of 5 ohms and therefore makes them easier to control even though it's a big injector. Another note is that there are certain 9sec rotaries that everyone knows about out there that ARE FOR A FACT running these setups and will not admit, or lie about it because it's kinda like an "advantage" thing, they say it can't be done, meanwhile it is being done(even by some hardcore guys on this forum, that don't give anything up). So does anyone who's running this setup have anything to say about this, or are we just gonna play stupid? Ralph from Xcessive, I need to speak to you, lemme know when's the best time to reach you at the shop so we can talk about this.

 

OK guys a little update on the 1600cc primary injector subject, I spoke to some of my friends on the subject that have this setup and guess what?, their cars idle at 900RPM!!!!!, I stated about them idling higher before, but now I remember that it was when the car was cold, and it was in warmup mode. I also had a convo with a tuner that tunes their cars, and he told me that a 1600cc injector has a resistance of 5 ohms and therefore makes them easier to control even though it's a big injector. Another note is that there are certain 9sec rotaries that everyone knows about out there that ARE FOR A FACT running these setups and will not admit, or lie about it because it's kinda like an "advantage" thing, they say it can't be done, meanwhile it is being done(even by some hardcore guys on this forum, that don't give anything up). So does anyone who's running this setup have anything to say about this, or are we just gonna play stupid? Ralph from Xcessive, I need to speak to you, lemme know when's the best time to reach you at the shop so we can talk about this.