NXSLT1

I've been working ,for some time now, on my roots blower setup on the TA. It's a stock LT1 with the exception of headers and of course the blower. I'm running it on E85 and have it tuned to go into WOT as soon as it goes into boost and I have the meth coming on as soon as it sees boost. WOT AFR is usually around 11:1. I just installed a meth/water injection kit on it and it does absolutely nothing for the car, nothing. The air temps never go down and I still get knock out the ***. I have the injector going in right above the blower. Normal driving the air temps usually hover around 165* and when under boost the meth never drops them. As matter of fact they climb and climb. In just a quick 5 second blip of the throttle they will reach around 190* Am I doing something wrong? Is the windshield washer fluid stuff a joke or is there a certain brand of windshield washer fluid I should use? The bottle doesn't say what mixture it is.

I'm lost, point me in the right direction.

NXSLT1

So nobody knows anything about meth injection??

Boostaholic

iTrader: (4)

You can always go buy pure meth and mix it 50/50 with water.

NXSLT1

How far up in the airstream should I be injecting it? I've got it going in right at the blower and that's pretty much right at the intake manifold. Wonder if I moved it back would it mix better or does that not matter?

BOONE

iTrader: (4)

Use straight meth and use vp m3, its oxigenated 3%. I would never use it diluted especially trying to enhance the ethanol. You could move the jets back some if you want but you are probably not hurting anything where you are. You might try to inject more, these cars can take alot. It will bog when its too much, then just back down a slight bit. You are probably just not shooting enough.

NXSLT1

Is there a certain size jet that I should be using? I'm assuming that's how you shoot more, bigger jet. I have no clue what size this jet is. It's a cooling mist kit.

BOONE

iTrader: (4)

I would call and ask what size it came with and go from there if you are going to order one. I also have the cooling mist kit. I had been running two 13 gph jets and I'm in the process of switching to two 16 gph jets then back to tune, or if that's too much a 13 and a 16 or what ever works out. Two 13 gph jets worked real well though at 11 lbs of boost with my other mods in my sig, but that was with gas. You will have to just see and let us all know, its kind of interesting with the ethanol and all. Boone

NXSLT1

It came with a 12 GPH jet. I got the bright idea today of drilling it out a lil bigger to see what would happen. The original hole is about .030, I drilled it out to .055. I checked the spray pattern and it was still good but I could tell it was spraying ALOT more after drilling it out. Took it down the road and of course it just bogged. AFR was around 9.8. It's definitely doing it's job now though. After I took it for a spin the blower was cold as a cucumber while the rest of the motor was hot. The blower is usually so hot you can't touch. I didn't get any knock except for the time it took for the meth to get going good, which was just a second or so. Now it's just a matter of dialing in the right size jet. I'm gonna try an 18GPH and see what that does.

NXSLT1

I got the 18GPH and it's too much. He doesn't have anything in between a 12 and an 18 so what now? When it bogs does that mean it's too much period and not even taking out fuel in the tune will help? I tried to take out fuel in WOT and I'm at the limit of taking it out and it hasn't done a thing to bring my AFR inline and it stills bogs like crazy. I'm gonna assume it's too much meth/water period and I have to back that down. I'm sorta cornfused on how all this works as far as tuning it.

I guess I could go with a 12 and a 3.9. The one nozzle that I drilled out was pretty much where I need to be and from guesstimating it's about a 16GPH but the spray pattern isn't exactly right now. Might stick it back in and see what happens.

ocdwill

how many pounds of boost?

NXSLT1

6-7 lbs.

ocdwill

sounds like you need to tune the car first....meth injection helps with being able to run more timming and boost...and i know you know how it works...but i find that on low boost apps will not work well..( you are in the low range)..will your car (ping) when its cold ?

NXSLT1

The car is tuned. I just added the meth in the last couple of weeks due to the knock I'm already getting. It knocks as soon as it crosses over into boost with only 5* timing. I haven't really gotten it to run on the meth yet, not right anyway. Remember this is a stock compression motor, 10.5:1 with a roots blower not a centrifugal. I'm to the point of believing nothing is going to work until I drop compression.

I'll keep messing with it, maybe I'll stumble across something eventually.

No Juice

iTrader: (11)

I can't believe you are getting that much knock on E85 and only 6-7lbs ? Something doesn't sound right even if its 10.5:1. Where is the IAT sensor? before or after the meth injection?

I've seen LT1's run 14lbs non-intercooled with no knock.

RW99

You're in some uncharted territory here... since you're on E85 you're already pretty close to 105 octane, right? So if you inject anything other than 100% methanol you're actually going to decrease the octane content of your fuel if you start to pull out E85 to compensate for the methanol added.

Also, the roots blower. I'm not sure how the methanol injection affects the efficiency of your supercharger... I think many (most?) guys spraying methanol are adding it between their turbo/blower and the throttle body. So you apply the alcohol to the hottest air and achieve more complete vaporization and therefore better cooling. I'm pretty sure this is why you're not seeing your IATs dip.

Maybe a methanol system just won't help your setup.

98turbls1

iTrader: (17)

Also don't you have to be somewhere around 9.* AFR with E85?? That may be why you're still pinging... Just a thought...

NXSLT1

I've often wondered if I was getting false knock but it doesn't happen until it's in boost and it does it everytime so I'm pretty sure it isn't false. I can't actually hear the knock because of the exhaust but it definitely shows up on the datamaster.

The IAT sensor is in the intake manifold after the blower so I get a true reading of the air temps. They do drop when the meth kicks in. Usually a 5 second or so burst will drop them from 165 down to around 110. I won't stay in the throttle any longer than that because of the knock I get. The meth is spraying right in top of the blower. That way the blower gets cooled and it helps mix it up in the air also. I know the meth is at least cooling things down because the blower is cool right after a burst of meth. Before the meth was added the blower would be so hot you couldn't touch it.

The first nozzle (12GPH) I had wasn't big enough and it didn't do anything for the temps. I drilled that one out while waiting for the second bigger nozzle to get here. It dropped the temps but was shooting too much meth. The second nozzle (18GPH) is too big also, it just bogs. I soldered up the first nozzle and drilled it out again with a smaller hole than the first time I drilled it out and my AFR was dead on but I had added a lil timing at the same and was getting knock. I'm gonna back the timing off again with the drilled out nozzle and see what it does.

What are these stock compression LT1's that are running with 14 lbs using? Do they have an intercooler, meth, both?? I have no room for an intercooler. The meth should work, I just need to figure out what I'm doing. This is all new to me.

The E85 is 105 octane and I really thought that would be enough but it isn't apparently. If you have yer wideband calibrated for the ethanol then yer stoich AFR would be around 9.7, max power rich would be around 6.97. BUT if you don't calibrate yer wideband for it then you just use the AFR numbers you would for gasoline. Trust me, it took some researching, reading and alot of head scratching to figure that one out as I'm new to tuning.

Thanks for the suggestions, keep them coming and I'll keep posting up what works and what doesn't.

BOONE

iTrader: (4)

No water bud. 18 should not be too big at all, well I would not think, hard to tell though with the ethanol and all. Bogging with that small of change sounds like too much water it can happen from too much meth or water but it takes a lot of meth to bog and not so much water. I would never run water at all because its not a fuel. I know it gulps up heat really good but, its still not a fuel and that is a waste of time to me except for the fact that it makes the meth non flammable. If your changing the fueling in the tune and its not responding, then its the non fuel portion of the charge. I bet if you remove the water completely it would possibly take quite a large shot and your kit would make you quite happy. Boone.

NXSLT1

Now that makes sense. Only thing is my pump says no more than a 50/50 mix. Yer running the cooling mist pump right? Haven't had any trouble with it on straight meth??

BLOWNBLUEZ06

iTrader: (17)

First off, the roots style blowers do not respond the same as centrifugal blowers to meth injection. Second, someone above me mentioned to inject between the blower and engine. This information contradicts that. Let me offer you some supporting documentation that I read on this.
"It seems even now to be a little recognised fact that adding even a proportion of the fuel before the supercharger is a very effective method of lowering charge temperature by evaporation during compression as well as being a good method of mixture preparation. There is an efficiency gain here which is not immediately obvious. Cooling the charge as it is compressed is of more benefit than any form of cooling after the event (by an intercooler for instance, although further intercooling may still be beneficial) because the work consumed by the compressor will be reduced. Water or water/methanol injection can be used for the same purpose. This important advantage is denied to the Roots device because of its lack of internal compression. Stanley Hooker estimated that adding fuel ahead of the supercharger dropped the air temperature by 25 degrees C on the Merlin, enabling it to consistently outperform the larger and supposedly more advanced German engines with direct fuel injection into the cylinders. Fuel has to be added anyway so why not add it where it will do most good? "