NXSLT1

Boone, how can you being running that much meth and it not change yer AFR? I had it tuned to a 12.5 WOT AFR (seems to be where I don't get much knock) just on pump gas then turned the meth on and it drops mine to below 10, this is with the 18gph nozzle. The WOT tables are at -20% now and it's still barely above 11 and getting knock out the *** and spits and sputters and runs like ****. And it does absolutely nothing to the air temps. When I hit the throttle the temps climb and climb until I let off the throttle. Obviously I have no clue what I'm doing because pure meth is making it run worse than just pump gas alone.

Tell me what I'm doing wrong, I'm no tuner by any means, more of a fabricator, but I'd like to think I understand what it takes to tune one..... here's my entire setup.........

stock LT1 10.5:1 CR with exception of headers and true duals
weiand 142 roots blower non intercooled
running 5-7 lbs of boost
42 lb injectors
walbro 255 fuel pump
2 bar map sensor
I don't have a controller for the meth injection, just the pump, boost switch and nozzle. I have the meth coming on as soon as it goes into boost because I get knock as soon as it goes into boost. I basicaly have a stock tune with the exception of some things changed in the IAC tables to make it idle and timing taken out at 50 kpa and above. Max timing in boost is 8 freakin degrees and I still get knock out the *** no matter what I do. I'm running the stock coil at the moment, will a hotter coil make a difference??

Should I make it go into WOT as soon as it goes into boost or leave those settings alone? I keep reading that the AFR for boost is around 11-11.5 but the leaner I go with it the less knock I get. I've tried it from 11 up to 12.5 and the meth just seems to make it worse. It does seem to do better with the smaller nozzle tho. Seems like to me it should have ran on E85 since it's 105 octane, I'm only pushing 7 lbs max. I'm tempted to put some methanol in the tank and just see what it does. Surely it should run on pure methanol without any knock, right??

NXSLT1

Well, I took the CAI off the top of the blower yesterday to change the meth nozzle and found a couple of troubling things. One, I had a huge amount of meth puddled at the bottom of the CAI and two, there is oil everywhere in the CAI, blower and intake manifold. The oil is actually puddled up right in front of the intake ports along with being everywhere else. How much does oil affect knock and ping? I've got to redo my pcv system before I go any further. I've also got to relocate the meth nozzle, it's spraying across the airstream right before the blower inlet right now. I read somewhere that it's best to have it spraying against the incoming air for best atomization, is that correct?

Here's an old pic but the red arrow shows where the nozzle is now and the blue arrow is where it's puddling badly. I thought about putting it where the black arrow is, at least it will be further back in the airstream and maybe atomize better. Any suggestions??

98turbls1

iTrader: (17)

Oil can create knock like crazy... You definitely have to get that fixed, change the plugs, fix the meth, and then I bet it will be a million times better....

RW99

Ditto the above; oil in the intake will induce detonation and you'll see knock. If reworking the PCV system (and adding a breather?) doesn't prevent the problem then maybe a compression/leakdown test is in order... or are you sure that your rings are happy?

As for the puddle of methanol, my guess is that there's not enough heat in the intake tract to vaporize all of your spray. This would make sense, because it looks like you are spraying prior to the compression of your air charge (where the heat is generated). IMO, until you can apply the methanol spray to heated/compressed air, you won't see any benefit.

BOONE

iTrader: (4)

The way I can run that much meth without it changing my afr is by using the m3 from vp racing, the afr is sort of figured in with the oxygen content so it don't affect it. You can probably control your puddling somewhat by going to the progressive controller, its probably puddling mostly when it first comes on, all at once at low boost/rpm, this is where the progressive controller would help tremendously. My thoughts on putting the jet at the black arrow is that it would still be prone to puddle. I would look for a place right under the blower to inject, maybe two places for better distribution/atomization with two jets half the size of what you have. I would try the moving of the jets first, you should be able to run a non progressive setup especially with a blower that comes on so early. Then if it still bogs get the progressive setup and tune it that way. Def get the pcv thing worked out first though like everyone said. Hope this answers all the questions you asked me, Im not very familiar with lt1s or the blower you have so Im not too much help. Boone

NXSLT1

Yall have been very helpful. I didn't think about the oxygen content in the meth, that would explain no change in AFR, it brings it's own O2. I'm heading out to the garage now to put it back together. Maybe I'll get it figured out eventually.

04Mark

Do you have a solenoid used in your meth kit? Your supposed to run one if your nozzle is mounted after the throttle body. Otherwise the vacuum from the motor will draw alky threw your nozzle. So either move the nozzle infront of the T/B or you need to run a 'noid in your meth line. As far as the oil I would put a one way check valve after the pcv.And if you have any other lines from the valve covers going into the supercharger or before it disconnect them and use a catch can or a breather(the breather might lean out your tune).
~Mark

NXSLT1

No solenoid, I thought about that but I don't think that's the prob. I get plenty of meth according to the AFR readings when it comes on. It wouldn't be a bad idea to have one though just to make sure the meth doesn't get sucked out of the line and it's right there waiting to be sprayed.

Not sure what the purpose of a check valve would be. I put a couple of water seperators (like you would use on an air line to catch moisture) on each hose, it's catching the oil nicely now. Might eventually make a bigger catch can.

Got a question about pcv tho, the way I have it setup right now is I have a hose from above the blower (on the vacuum side) that goes thru the pcv valve which is in the back of the intake going into the lifter valley and then another hose going to the pass side valve cover. It basically sucks from two places and it's actually pulling a vacuum on the crankcase. Is this what I want or do I need to be letting fresh air back in like the stock system does? I've always read that the rings seal better with a vacuum on the crankcase.

Anyway, got it back together tues and took it for a drive. Still got knock after the oil problem was cured, the meth still makes the knock worse along with making it run like ****. It backfired twice on me then starting missing on several cylinders and now it won't give me any more timing than 5 degrees no matter where in the rpm range it's at. I don't know if it's the opti, icm or ecm went bad.

RW99

Still have methanol pooling in the intake?

NXSLT1

Didn't get to run it long enough before it backfired and started running like ****.