Will 42lb (+20's) be all I need?

[glhs875]

I've had my boost to as high as 28psi several times with the SC6152. All I'm running for fuel is, 2 pumps in parallel with the external mount being a 255L. and 42lb (+20's) along with a 60#per hr progressive alky nozzle and a reworked 2bar cal.. Iam going to get a wide band O2 to verify, but I seem to have enough fuel for 28psi. My bsfc seems to be pretty low, which is a good thing. I don't know exactly how much HP I'm making @ 28psi, but it's feels like ALOT!!! I don't really understand how raising efficiecy can lower bsfc. I always expected to keep having to add more and more fuel. I guess there will come a time when I will have to add some more again as power goes up, I don't know. I did have to add about 16 to 18% in the off boost and lower boost levels though. Iam a little confused in the fuel consumption dept.

[8valves]

I guess your alky is making up for a lack of fuel injector capacity. I was on the ragged (comfort) edge of +40's at 26 psi at 370 whp. IDC was around 85%. The alky throws everything I know out the window.

AM

[glhs875]

I guess your alky is making up for a lack of fuel injector capacity. I was on the ragged (comfort) edge of +40's at 26 psi at 370 whp. IDC was around 85%. The alky throws everything I know out the window.

AM

Iam sure the alky helps. Before the alky I was running (2) 33lb aux. injectors both full on after a certain boost, but activated at different boost levels. The size of the alky nozzle works out to be about the same which is more like a 70lb per hr nozzle now that I think about it. That works out to be the same as around (4) 60lb injectors. I guess I'm flowing more fuel than I realized! I still thought I would be needing more though at the high 20psi levels.

[cordes]

I would agree that the alcohol is making up for the lack of fuel. Even those with a much more mild setup than 8valves start pushing the +40s at 25-26PSI with no alky.

I would also look at the duty cycle, as the RPMs that you turn with your setup would certainly make me think twice about running smaller injectors like that. There is a spreadsheet on D-cal which you can use to play with that. If I were you, I would probably step up to some 72pph injectors and supplement with alky to stave off det rather than relying so much on it as a now primary source of fuel.

my .02

[glhs875]

I would agree that the alcohol is making up for the lack of fuel. Even those with a much more mild setup than 8valves start pushing the +40s at 25-26PSI with no alky.

I would also look at the duty cycle, as the RPMs that you turn with your setup would certainly make me think twice about running smaller injectors like that. There is a spreadsheet on D-cal which you can use to play with that. If I were you, I would probably step up to some 72pph injectors and supplement with alky to stave off det rather than relying so much on it as a now primary source of fuel.

my .02

I want to keep at least the same amount of alky flow. I love it! I may set it up with (4) smaller nozzles or injectors, one for each cylinder. I have plans to get more aggressive in some areas that the alky will allow. Like bumping up the compression ratio from the 7.9 to 1 that it is now, to 8.5 or so for one. Detonation seems to be non- existant. Even with VERY aggressive timing under boost, and with only the alky and 93 octane. No need at all for race gas with the way things are right now. Unless Matt changed the duty cyle in the upper map range, I didn't tell him to, the duty cycle at max boost should be whatever is stock on an 86 T1 cal. Whatever that is, 85%? I think I will end up needing a little more cal tuning once I start turning 7000+R's again to get things just right up there. That may tell the tale on the +20's!

[8valves]

The only thing I get nervous about with alky is if the pump fails, or if the line gets clogged, etc, you're done and you won't even know before it's too late. You may have even more of a severe situation with it since you're relying heavily on it as a detonation suppressant. Trust me- at 28 lbs on just straight 93 I blew a whole inch of the #4 fire ring OUTSIDE of the block. That's on 72 pph's w/ no alky, also roughly 7.4:1 compression. Detonation will be there if you lose the cooling of the alky.

AM

[cordes]

OK, well then you are going to want to look at what Carl did with his alky setup. He ran 4 mister nozzles (one per runer) and made a cal to cut out the fuel as the alky came on. that would proably be the way to go for you. Have you thought about converting to E85 or straight alky?

[glhs875]

OK, well then you are going to want to look at what Carl did with his alky setup. He ran 4 mister nozzles (one per runer) and made a cal to cut out the fuel as the alky came on. that would proably be the way to go for you. Have you thought about converting to E85 or straight alky?

E85 is not avaiable in my area yet. When it does get here I will covert. I could just buy a drum of methonal and mix my own for now. I've thought about it. Carl's setup seems to work real well. On the cal, bleeding off some boost to the pressure reg. can help with tuning when using a secondary fuel system as well.

[glhs875]

The only thing I get nervous about with alky is if the pump fails, or if the line gets clogged, etc, you're done and you won't even know before it's too late. You may have even more of a severe situation with it since you're relying heavily on it as a detonation suppressant. Trust me- at 28 lbs on just straight 93 I blew a whole inch of the #4 fire ring OUTSIDE of the block. That's on 72 pph's w/ no alky, also roughly 7.4:1 compression. Detonation will be there if you lose the cooling of the alky.

AM

Here's the deal on that. If Iam relying on a large amount of alky for fuel enrichment, if it does stop pumping or something, there will be a HUGE noticable drop in HP, almost like hitting a brick wall. No problem with lifting on the throttle quickly. Much more noticable than using a small amount would be, if noticable at all. I feel it is safer when using 2 different fuel systems to split them in the middle or so. That way if either system has a problem, it is instantly noticable. And there is always some risk no matter what fuel setup we are using, pushing things as hard as we do. If it blows, just shake it off, and build something even better!!! :thumb:

[Aries_Turbo]

if it fails youll prolly melt stuff far sooner than you raise your foot off of the throttle.