jdbaugh1

iTrader: (1)

Right now I have my methanol injection nozzle right before the throttle body. If I am holding upper engine rpms, above 3,500, and hit the gas I get a short amount of pinging before the methanol reaches the combustion chambers. About the same amount of pinging you would have as your knock sensor picks it up then compensates by retarding the timing.

Anyway, I was wondering if any of you have injected into the intake manifold to try and reduce the latency a bit. I was considering trying it with two nozzles pointed at each other on opposite sides of the intake manifold. My main concern is getting inconsistent mixtures in the independent chambers. I was wondering if any of you have injected into the manifold and how you did it and if you experienced any issues.

Sharkey

iTrader: (1)

i had that same problem when my car was being dyno tuned. we were able to make 270ft/lb torque on a 4th gear pull, however running the car through the gears showed knock just after the gear change, and it ramped the timing back in slow enough that it showed a significant loss in torque. brining the turn on point down helped, but not enough. ended up having to back the timing down a couple degrees in the lower rpm to keep it from knocking, and as a result lost 10ft/lb.

what meth kit are you running? ive got a devils own with a pressure switch, old technology. we have found this same issue on several different vehicles on the dyno with different meth kits (devils own, snow). part of the reason it happens is because when the kit hits its turn on point, be it a pressure switch style or a progressive controller, it has to build enough pressure in the line to open the check valve and start spraying. it happens fairly quick, however not quick enough and on a gear change causes knock. the AEM kit has a feature that pulses the pump at a low duty cycle to keep the system primed so as soon as the boost hits the "start" setting its spraying out the nozzle.

we had the exact same problem on a supercharged s2000 that was making around 420hp, after a shift it would knock and pull timing before ramping it back it. the snow progressive kit was taken out and an aem kit was installed and the problem was gone instantly, no tuning changes whatsoever. at some point im going to put an aem kit on my cobalt and try to prove the same thing, however i see no reason i wouldnt see the same results.

jdbaugh1

iTrader: (1)

Running devils own with the progressive controller. Have progressive part start as low as possible (~2psi) and come full on at 10psi. I have the start point low to try and help prevent this issue.

100% METH

iTrader: (3)

Highly recommended you leave it pre throttle body.

The constant pull of vacuum on the diaphragm of the boost switch or controller will dull their ability to spray at your specific PSI settings.

Here's what you should do to prevent your tip in knock without having to create a valley between the transition from cruise/part throttle advance to WOT advance.

Run two jets in separate stages

A single .75gph jet @ 1 PSI, or just as you exit vacuum.
Water Meth Methanol Alcohol Injection Nozzle Fuel Jet Injector 75 GPH 47 ml MIN | eBay

Recommend running two solenoids

Water Methanol Alcohol Injection 300 PSI Mini 1 4 in Push Connect Solenoid | eBay

1.5-20 psi boost switch

Water Meth Methanol Alcohol Injection 1 5 20 PSI Boost Pressure Switch Hard Line | eBay

jdbaugh1

iTrader: (1)

Do you think this is much different than just running the progressive controller with a single nozzle? I know coming on at vacuum will be just a tad earlier than 2 psi progressive but is that enough to stop it? When I have the problem I am usually in high enough RPMS that when I hit the gas it seems I am pretty much instantly over 10 psi. Just trying to educate myself a bit more before I spend the money..

100% METH

iTrader: (3)

The idea is to have it spray pre-load

Only other way to combat it is to create a valley between your WOT cells and your part throttle cells in the advance table.

Multiple nozzles are always a better option as well.

3 x 2gph nozzles fogging your intake vs one 6gph nozzle will provide better atomization and distribution over all.

Smaller the nozzle is, you'll have less pressure drop, and fewer droplets.

Check this out

Prometh Water Methanol Alcohol Injection 2 5 in Mist A Pipe 2 Stage Tri Nozzle | eBay