Experts: Runner length and volume?
01-06-2005, 07:22 PM
#31
Guest
Posts: n/a
Re: Experts: Runner length and volume?
Originally Posted by articfriends
Kennywould,you also made impressive dyno numbers(really close to what my 540 made on dyno with m-3 procharger at 6 psi boost). Fill us in on your combo(.050 duration,cam specs,compression,injector size,exhaust etc). Are you using mefi3 controller,who did your program for you. Did you use progressive linkage on your throttle bodies or do they open at same time. Are you using a stock tps on just one of them to tell computer info? Are you using merc iac motor and map sensor mounted to your custom top half?How much fuel presure/injector size?I am learning a little more every time someonetells about these fuel injected combos!
GPM,does the fast controller come with a base program that you tweak with laptop on the dyno at different settings and pulls or do you have to start at square one and create a program and make 100's of trial and error pulls on the dyno? Are you running somekind of exhaust sensor that modifys fuel curve (o2 wide band or something). I'm gunshy of getting a different fuel injection and trying to get program right while test driving boat under boost on water(one lean run and its all over!). Obviously you must have to start out fat and sloowly lean it down until its still making safe power,ive kind of done this already with factory fuel injection on my boat with blown 540 by slowly stepping up base timing and adjusting boost referenced fuel presure.Do you run a flat given fuel presure and make adjustments to your pulse width with your set-up or are you raising fuel presure with boost? I hate the boost refernced set-up on my boat,it's too rich at part throttle boost and i'm definately going to run bigger injectors in whatever fuel injection i run next year and use the two bar map sensor to tell computer to adjust fuel curve,i'm currently doing both and its NOT precise. Thanks for any info,I haven't been able to get any exact answers from the "fuel injection experts" other than multiple reprograms of my controller,Smitty
GPM,does the fast controller come with a base program that you tweak with laptop on the dyno at different settings and pulls or do you have to start at square one and create a program and make 100's of trial and error pulls on the dyno? Are you running somekind of exhaust sensor that modifys fuel curve (o2 wide band or something). I'm gunshy of getting a different fuel injection and trying to get program right while test driving boat under boost on water(one lean run and its all over!). Obviously you must have to start out fat and sloowly lean it down until its still making safe power,ive kind of done this already with factory fuel injection on my boat with blown 540 by slowly stepping up base timing and adjusting boost referenced fuel presure.Do you run a flat given fuel presure and make adjustments to your pulse width with your set-up or are you raising fuel presure with boost? I hate the boost refernced set-up on my boat,it's too rich at part throttle boost and i'm definately going to run bigger injectors in whatever fuel injection i run next year and use the two bar map sensor to tell computer to adjust fuel curve,i'm currently doing both and its NOT precise. Thanks for any info,I haven't been able to get any exact answers from the "fuel injection experts" other than multiple reprograms of my controller,Smitty
, at .050 272/280, 748 lift, only one throttle body has the TPS, its progressive, 55lb injectors, if I remember correctly somehwere around 42/44 on fuel psi, jeeez have to keep some secrets, your the first to see that intake 
, I ran down a new 275 Baja with a blower on it and passed him with my 272, he wasn't real happy agout it! Gpm does my tuning 
01-06-2005, 07:51 PM
#32
Re: Experts: Runner length and volume?
Smitty, that's a lot of questions, the Fast system has a base program, but you would have to set it up for your combo. Put in your cid,4,6, or 8 cylinder, 1,2 or 3 bar map, injector size, timing 50 degrees for bbc. You have a wide band o2 option, helps a lot, it can add or subtract fuel. You have to set up A/F ratios, timing map, accelleration maps, most of it can be done with power on,motor off.I always run a boost referenced regulater, 43 lbs at idle, most injectors are rated there. Once you get a program together, fire it up, let the fun begin. Start with the idle work your way through the maps, starting with fuel,sometimes it's a pain in the ass, as you get the maps closer you start making data logs and fine tune. It takes a while and I don't type fast enough to explain it all, I've been at it for almost 15 years now, I like EFI because I can run big cams, big heads, make decent power, and still idle around 1000 rpms or less. My wife unloads ands loads the boat, I can tow skiers,and go out and run over 140, all in the same day. TC. didn't mean to hog the thread, I think I'm doing good with the tunnel rams and EFI, but really don't have anything to compare to.
Last edited by GPM; 01-07-2005 at 02:49 PM.
01-06-2005, 08:01 PM
#33
Registered
Re: Experts: Runner length and volume?
Is intake runner length more critical on a carb motor than an injected motor? It seems it would be more critical on a motor with a wet manifold to promote optimum fuel atomization where with an injected motor that is done with higher fuel pressure and the injector. Is anyone familiar with the old school trumpet type of Kinsler or Hilborne systems? Most of these were mechanical fuel injection, but they can now be used for EFI. I know they sold different length trumpets for tuning purposes. I love the look of those systems!!
Craig
Craig
01-06-2005, 08:11 PM
#34
Re: Experts: Runner length and volume?
Originally Posted by WETTE VETTE
Is intake runner length more critical on a carb motor than an injected motor? It seems it would be more critical on a motor with a wet manifold to promote optimum fuel atomization where with an injected motor that is done with higher fuel pressure and the injector. Is anyone familiar with the old school trumpet type of Kinsler or Hilborne systems? Most of these were mechanical fuel injection, but they can now be used for EFI. I know they sold different length trumpets for tuning purposes. I love the look of those systems!!
Craig
Craig
01-06-2005, 08:24 PM
#35
MarineKinetics
Platinum Member
Re: Experts: Runner length and volume?
Craig,
Kinsler is developing a 3 piece EFI stack injection system that was scheduled to be introduced the first of this year. It features short and long runner configurations with 2.5/2.9/3.0 throttle diameters, depending on the application. If you need more info let me know.
Bob
Kinsler is developing a 3 piece EFI stack injection system that was scheduled to be introduced the first of this year. It features short and long runner configurations with 2.5/2.9/3.0 throttle diameters, depending on the application. If you need more info let me know.
Bob
01-06-2005, 08:41 PM
#36
Registered
Re: Experts: Runner length and volume?
Bob,
That system would be awesome, not only in performance but in esthetics!! I'll bet Kinsler will want upwards of $12,000 for that package! I wonder if it will be coast guard approved for use in a closed engine compartment?
If my memory serves me correctly I believe Merc used a system similar to this on the class 1 race motor. It was a solid roller 499" 12.8:1 compression big chief head motor. Made around 900 HP at 6800 RPM!!
That system would be awesome, not only in performance but in esthetics!! I'll bet Kinsler will want upwards of $12,000 for that package! I wonder if it will be coast guard approved for use in a closed engine compartment?
If my memory serves me correctly I believe Merc used a system similar to this on the class 1 race motor. It was a solid roller 499" 12.8:1 compression big chief head motor. Made around 900 HP at 6800 RPM!!
01-07-2005, 12:41 AM
#37
Platinum Member
Platinum Member
Re: Experts: Runner length and volume?
Originally Posted by kennywould
I figured you would have questions , at .050 272/280, 748 lift, only one throttle body has the TPS, its progressive, 55lb injectors, if I remember correctly somehwere around 42/44 on fuel psi, jeeez have to keep some secrets, your the first to see that intake , I ran down a new 275 Baja with a blower on it and passed him with my 272, he wasn't real happy agout it! Gpm does my tuning
, at .050 272/280, 748 lift, only one throttle body has the TPS, its progressive, 55lb injectors, if I remember correctly somehwere around 42/44 on fuel psi, jeeez have to keep some secrets, your the first to see that intake , I ran down a new 275 Baja with a blower on it and passed him with my 272, he wasn't real happy agout it! Gpm does my tuning ,i should be able to compare my speed at 630hp to your speed at 770hp and factor exactly how much hp i'm currently making to achieve my current speeds,thanks,SmittyPS KENNYWOULD,did John Force notice his spare cam missing out of his parts trailer
,THAT IS HUMUNGOUS!!!!!Tomcat,sorry we aren't really talking about runner length but some good stuffs coming out!!
01-07-2005, 10:39 AM
#39
Registered
Join Date: Jan 2004
Location: San Diego, California
Posts: 2,777
Likes: 0
Received 6 Likes
on
6 Posts
Re: Experts: Runner length and volume?
On the question about taper in the runners. Runners should taper approximatly 2% per inch of runner length from the opening towards the valve on a constant smooth basis if possible. This will increase velocity and the ram effect. As for which benefits more, runner redirection is more critical in a wet( carburated) manifold, because when wet air changes direction(curves) it will let more fuel drop out of suspension. Remember fuel (heavier) and air don't weigh the same and hence change directions at different speeds. The runner length determines where the rpm power band of a manifold will be and the taper helps develop the speed of the charge.
Ray @ Raylar
Ray @ Raylar
