ChevyNo1

Well, went down to Streetflight today to dial in the water/alky . . . got a #10 jet in there now, I still think I could go even bigger. But for now, I'm quite happy

The graph shows two runs; the first one is how I drove it in off the street. Running at 8psi, 91 octane, no water/alky. The 2nd run is at 10.5/11psi, 91 octane STILL, and water/alky running. This time I pulled fuel in LS1-Edit to account for the alky, I did not do that my last dyno session. Note the really safe A/F. I have no running knock sensors, so this was all done by ear. No detonation showed on the graph and none could be heard. The part I'm really happy about is this is a really safe street tune on crappy 91 octane!!!



Nic had no idea I was still running the stock driveshaft; how long do you think it will last with that torque launching at 5K rpm??

And as always, BIG thanks to Nic for his knowledge on tuning, I couldn't have gotten this far without him!!

- Dug

Blackbird

WOW!

Congrats Dug. The ol water/alky kicks but doesn't it

Glad to see you finally dialed it in.

ChevyNo1

Thanks Heath! Definitely works quite well . . . I still can't get the car to bog with this jet though, I know I need to go the next size higher . . . squeeze a bit more out!

- Dug

Ken G

iTrader: (1)

Great numbers! What are you using for a reservoir for the injection system?

-Ken

Tin Indian

Dug's Chevy is a BIG DOG!

I ran him on the highway coming home from the dyno and pulled him by at least 4 car lengths on a short race going from 70 to 100.



























Wait ... Maybe I got it the other way around
I'm so confused right now!

Tin Indian

Seriously ... I was at the dyno today with Dug.

Dug's SS make absolutly great numbers. Other than the turbos, big injectors, good tuning, and water injection, that car's engine is bone stock (even down to the valve springs)!

All on good ol' 91 octane Arizona gas .....

VINCE

iTrader: (1)

Awesome. Congrats!!!!!!

SuperTrooper

Move to FL and try some of our 93oct!

NicD

iTrader: (7)

Yes, today was a fun day. Just thinking about you having all that available whenever you want as much as you want pisses me off.

Tin Indian

Nic is a great tuner. Sure worked out some of the bugs on Dug's car with LS1Edit ...

ChevyNo1

Nic is the best!!!

Ken, I've got the SMC kit, so I got the gallon reservoir that he supplies with the kit. For anyone on here with the SMC kit, I still can't get the car to bog as he describes. I've got a #10 jet in there, do I need something bigger with 11psi? Also, I'm running 50/50 water/alky, but Steve suggests 100% alky. Could that be why the car wouldn't bog with the pump at full speed? I just think I'm not yet seeing the full benefit of this kit.

Ron, you stayed right even with me until the boost kicked in! Once I hit about 4K it started climbing quick!! It's quite a rush Thanks for going with me, now I have some proof

- Dug

Blackbird

Dug, you don't have to force it to bog. They use that as a reference for people to tune blind. You are doing it the right way. Tune it to a safe a/f with no detonation and your set. You don't need a bigger jet unless you plan on cranking up the boost even more. Again with running pure alky, imo, no need unless again your planning on cranking up the boost. Hopefully Steve (just_me) will chime in, but this is how I understand things to be with water/alky injection.

ChevyNo1

Well that's the thing . . . it was up to full pump speed and I still heard detonation on the last run . . . 4 distinct snaps. I am running stock compression on 91 octane, so maybe I've just reached the limits of my situation . . .

- Dug

Blackbird

ohhh ok.

maybe you do need a bit more, or perhaps upping the alky to water ratio may help?

easy enough to try at least.

Noyzee

iTrader: (37)

Congrats, great #'s!!
I ordered the SMC kit for my car, but sold it to my buddy with a GN. he needed it more then me.
If you wanted to push it, throw some good gas and a 70/30 mix of alk in it and up the boost. If not, those #'s now are great.
Go get some track times!

S_J_H

That is some very impressive power for 91 octane.
A few questions,
How much timing are you running?
Is the #10 jet a 10 GPH nozzle?
What were your charge temps?
Maf flow in lbs/min?


My engine ran nice and smooth at 9-10psi and 15 GPH of 50/50 mix.
When I went to 13+ psi it begain to have serious knock with anything more than 20' timing.
Perhaps maybe I might try another round of tuning with my alky system before I retire it for good.
Steve

ChevyNo1

Thanks Noyzee . . . ya, better gas will definitely help. I just wanted to get the max out of pump gas first, and then put some good stuff in.

Thanks Steve! I was quite happy with the results, since I have stock CR and crappy gas.

I believe he added 1 more degree of timing which puts me at either 16 or 17. I THINK the #10 jet is 10gph, but not positive. I did not autotap my runs, but from previous logs I run at most 30 degrees over ambient. Yesterday ambient was probably 70F. I DO know that at 10-11psi I'm maxing my MAF, we verified that the last time I dynoed.

S_J_H

From all the research I have done, best detonation control from water comes at 25-60% of water to fuel ratio.
We really don't need any alcohol but I think it does help a little.I mainly used enough alcohol to offset my maxed 42lb injectors.
I don't think pure alcohol is the way to go for detonation. It will help lower charge temps, but combustion temps will be higher.
An old NACA study showed that a water to gas ratio of .6 had the equivalent detonation resistance using 80 octane fuel as it did with 100 octane and no water.
But that's a tremendous amount of water! at least 35GPH for a 700 FLWHP motor on a 12.5 fuel ratio.
I think 20-22 GPH is about as much water volume as you want to try and flow through the intake.
That's about the same amount of wet flow as a 250hp throttle body n20 shot.
Which most will agree is about the limit before cylinder distribution problems showup heavily.

Anyhow, Use more water only if you need it.At only 10gph you still have a lot of room to add more if needed.

By the way,
Snowperformance is now selling a Nitromethane additive for water/alky systems for an instant 30-50hp gain.
Steve

ChevyNo1

Hmmm . . . great info!! I'm running 50/50 right now, so that puts me in the right area. Do you think I should try a bigger jet? Still got some knock in my best run . . .

How can you tell when you've got too much water flowing??

- Dug

S_J_H

Just so we are all clear, when I stated 25-60% water to fuel ratio,
I meant total volume of water to total volume of gasoline.
Not the ratio of water to alcohol.
A lot of guys don't run this much water because they are also richening up with alcohol.

I'll guess you are around 660 FLWHP. Maybe more.
So if you figure you were using fuel at a .5 BSCF( around 12.5-1) then you were flowing around 55gph of fuel.
So 10gph water/alky only puts you at a 9% water to fuel ratio and 9% alky to fuel ratio.
So if you are seeing Knock, Then yes I would add more water volume.
Those numbers are assumed on a lot of things like your fuel flow and FLWHP.
So they are probably off a bit.
You can figure it more exact of you calculate your injector flow.
But anyhow, you can probably add a lot more water but keep your alky volume the same or you'll have to retune your PE tables again to compensate as alcohol is a fuel.
Maybe try a 15gph nozzle at a 65/35 water/alky ratio.
That would put you at 18% water to fuel while keeping a similar air/fuel ratio with the 9% alky to gas ratio you are currently at.