Alky knock problem

[Vacuum 6]

I have an old BGC alky kit. I am able to run an 18° chip with 24 psi of boost on 93 pump gas. :happy: From a launch or walking into the throttle (once the car is moving any speed) the car does not detonate at all. Ok here is the problem…if I am cruising then nail it (alky system on) the car detonates badly. The turn on point of the system is set at 5 psi. Alky not getting into the mixture fast enough for the “nailing it” condition? If I go to a bigger jet the car bogs. Any problems like this with Razor’s or SMC kit? Any suggestions (other than buying a new alky kit)? Thanks.

[SMC]

You might upgrade the pump in that old kit to something newer from Razor or SMC. Those old kits were not known for high quality :dong:

A better pump should get the spray in quicker. One of the progressive controllers may also help avoid a bog from too much spray too quick.

[stevemon]

I would upgrade to a better pump too but I'd also throw some higher octane fuel in the tank & see if the problem still exists. You may just be getting false knock.

[Razor]

5 PSI turnon is typically too low for a pressure switch type system. You may be overly rich and cuasing the problem.

Do this, turn the boost down to 16 PSI. Turn the alky kit off.. now stomp the pedal and see if it knocks? You'd be amazed sometimes what you find.

If you cant get the car to run clean without alky.. it cant run clean with it. Put some high octane gas in the tank and see if the problem disappears.. You need to see if its an alky issue or something else.

Some cars with aftermarket cams can make the knock sensor flare off due to ramp profiles on the cam.. you again need to determine whats what :)

HTH

[dandman]

hi

i just bought a scanmaster and i see my car do the same, from a start to 17psi, no knock, from a rolling start 1-2 degrees of knock, i have a te61, 50lbs and casper chip, alky come on around 12psi, pump is set at 6-6.5, too little pump speed?

let me know suggestions, maybe turn pump speed higher?

thanks...dan

[SMC]

2 degrees transitional knock is not a problem. If it's an SMC kit, I'd recommend more pump speed and MORE BOOST. If you can run it wide open, go for it. Many guys run pump speed at 8-10 and 21 psi boost. Don't be afraid to tickle the knock sensor, 0 degrees knock is too safe IMO. I like to see a degree or 2 to let me know I'm "on the edge", and I've never blown a head gasket in 95K miles.

[dandman]

hi

smc, yes, its your kit, i sing your praises when i can, ok, ill try turning the pump speed to 8, should i increase my fuel pressure as well, i turned my boost up since my last post, 0-20psi, o2 reading was 779, o.oknock, same 6.5 pump speed, but if i give it boost at say 50 mph, o2 drops to 722 and i get 2.1knock, what do you think, normal?, or increase something, alky or fuel press?, your advise is like gold, all of you!

dan

[Razor]

Well the 722 may be a fluke. The scanmaster reads 1.5 frames per second, it may have read a glitch and not the correct O2. Only way to get a real handle is watch the O2 as its happening. If its like 790..795..790..720..790.. it will record 720 as the lowest yet the car is really running 790. Chip also plays a role in the way timing and fueling are dropped into the motor. Some chips like the extender employ a knock ignore if the chip senses a downshift.

When in OD for example and you slam the pedal down..tranny down shifts..bang.. this will cuase the knock sensor to pickup the metallic noise, which is not KR.

The KR your looking for is the top of the gears, be it 2nd, 3rd, 4th.. and watch it not escalate. If it does, lift. And the transitional KR which is a late turnon point on the alcohol system. depending on how fast the car spools.. will determine the point.

So to answer your question, 2 degrees is nothing. I would worry about a few degrees if running 30+ PSI. At 20 PSI with a stock motor..its nothing. As to why it does it, hope my explanation helps.

[SMC]

Good stuff, Razor!
Between us 2 I guess we know a little about this alky stuff!
It's hard to eliminate all knock under all circumstances.......you could lower the spray on point, but that could lead to a bit of a bog problem......It's a balancing act with a standard controller.....spray too early you might bog, too late you might get some transitional KR. But like Razor said- 2 degrees is no problem at a shift. 5 or more degrees at WOT at the top of a gear is where I get concerned.

[Vacuum 6]

I turned down the boost, no knock when stomping on the gas. Also I tried race gas…knock went away. With the turn on point set at 5 psi, my scan tool does not indicate a rich condition.

Does everyone agree that I need a better pump??? The BGC kit has a windshield fluid type pump. High quality…

[Razor]

Hey Steve..we do this cuase we like too :)

Vacuum 6.. if it doesnt knock at lower boost, doesnt knock with race gas.. your giving yourself the answer.. has to do with the alky kit.

maybe time for you to re-evaluate your situation .. my Buick crystal ball says.. a new kit is in your future :D

[Vacuum 6]

Thanks everyone for the help. :arco:

[Vacuum 6]

After talking with Razor he told me this first thing to do was check my pump pressure. It was determined the pump pressure was adequate for my HP level. Next I changed my alky mixture and pump turn on point. With straight denaturized alky and turn on point set to 12 psi no problems. I am running a 24 degree chip with 21 psi of boost...no knock with 93 pump gas. :rock: Thanks again for the help.