Alky settings track/street SMC

Razor

Forum tech Advisor
Staff member
Joined
Jul 31, 2001
Ok..heres my question.If I jab the throttle,I get a bunch of knock then it levels off.If I steadily get on it,the knock is nill.

Problem I'm having is if I set my turnon point to low,then it bogs when it hits that boost level.If I set my turn on point higher,then works great when I gradually get into it.But knocks when the throttle is jabbed.. until the alky catches up.

Same thing with the pump speed.Too much pump speed it bogs.Too little it knocks.

Do smc owners run into this?Where lies the sweet spot? is it a "set it to what your doing" thing every time.I mean turn up the pump speed and lower the turn on point when at the track..and raise turnon point and reduce pump speed when around town driving?

Thanks and sorry for the ramblings

Chip is thrasher100,stock turbo,stock inj.
 
I did not play with the thrasher 100 and stock injectors very long but I was having some high knock with both the thrasher 92 & 100. I was having other problems but I went to 38# injectors and a JC93 chip, the knock has gone way down without any tuning.
You might try a different chip. I have seen some other post that were having troubles with the thrashers & alky.
 
I've had the same problem with my alky kit. I would be interested in what others have done to eiliminate this.


Z
 
I'd like to know about more info on probs with thrasher chips and alky.

And good to know I'm not the only one having probs.

I wonder if spoolup were to be slower if the problem would be controlled.Just thinking out loud :)

Anyone else..please chime in.
 
This is the problem I'm having as well. I've tried a Reds 93, Thrasher 100, my old ATR Pitbull and it is still there, worse with the latter 2. Maybe I'll try my Thrasher 92 to see if that does it also.
 
How much boost do you run? I am running the same basic combo in my sig, and was running about 22psi on 92 octane with the SMC using denatured alky.
I have the turn on at about 11psi, no bog at all, and the pump is set to full all the time.
I found that the more I lowered my fuel pressure(39psi vac off) the faster my car went......pretty low for stock injectors I would think, but every car is different.:)
 
What alcohol are you using? Denatured will probably have a better time controlling KR than isopropyl. Might try changing the cocktail you're using and see if that will straighten out your situation. I had Thrasher 92 on stock injectors. It liked denatured with a 13psi turn on point, 70% pump speed, 18lbs boost on crappy BP 93 octane. 0.0 KR, maybe 0.5 when I hit it on the shift. And boy, can you ever smell that denatured.
 
Yep using straight denatured with a wd40 squirt.
If I set the turn on at 11 lbs with an aggressive pump speed...when tooting around town and the car hits the "on"it will bog.Different story at the track tho.

It seemed to like the thrasher 92 chip for KR but am trying to get a bit more aggressive on timing and boost level
 
I'm using the 91% isopropyl and water. I'm going to start trying denatured when my tank runs out.

FWIW, I'm only running ~20psi. My car doesn't like boost, or a lot of it anyway. On 100 octane, I could only run 18-19psi. I've been blaming on the stock stuff not supporting it. I'm slowly starting to address that issue :)
 
pump speed

I'm using a 20 degree chip with the pump coming on at about 11psi and the pump speed set at 5-6. Boost levels are at 23psi with a spike in first gear at 24 WOT. Knock is below 2 degrees at the 1-2 shift and 0 knock all the way through 3rd.. I only get knock at the 1-2 when the temps drop below 40 degrees due to that 24 psi spike. The chip is similiar to Joe Lubrant 93 chip but I changed the fuel constant, in his chip, from 47 to 43. Also running 009's for injectors and a pt51 with all the normal bolt-ons.
When I began tuning the Alky I always would tune it to where I would begin to set off the knock sensor during a WOT blast (less than 3 degrees). I then would turn the boost back one turn to be conservative.
 
With the stock turbo, intercooler and injectors I was running a Modern Musclecar 108 chip and 21 lbs of boost with SMC kit. I was getting no knock what so ever. I ran it with the MM 93 chip and it was lame so I put the 108 it and boy did it come alive. This was with strait denatured.

I am now running a reds 100 chip with 24 lbs of boost, but now have a pte 54, 55lb injectors and a v4 intercooler.
 
All good replies here. I liked what John Larkin said, because it worked for me! :) Once I switched to de-natured, and colder plugs (AC-43's) I had 25 psi, no knock at all. Lower timing helps if the cylinder temps are too high. *18 is good, no less than that.

Be sure that your car is not running high coolant temps. If so, that is the first thing to fix. Give your engine time to cool down between runs, as well.

BTW, I'm running alum heads, now, so no more 'AC-43' plugs.

Let us know how the de-natured worked. :)
 
Turbo Tim makes a good point. Give your car time to cool down. I was at a track rental a couple of weeks ago, and was letting it cool down for 1/2 hour to 45 minutes. Towards the end of the night I was trying to get in a few extra runs and was only waiting 20 minutes which wasn't enough I was starting to get knock where I wasn't with a proper cool down and was loosing about 2 mph.
 
Many thanks for the replies...really.

I guess the key is to run a very low timing chip and high boost.The more timing the chip has the more prone to knocking it will be since alky catches up.I also have been priming my system and that helps as well to curtail the KR.

I'm gonna be doing some playing around with a street chip I have and see how it responds to higher boost levels.

Also hot lapping the car at the track is a big no-no especially for our heavy-duty(BS) 200r4 trannys that love huge amounts of heat.

Julio

Anything/anyone else?
 
Keeping the car cool is what ive noticed is very important when running the smc, also pay attention to the weather. My car runs rich as hell(830 O2's) or higher if i leave the setting on 9 or 10 while running 21-22 psi during the day in 75-80 heat. But at night as the air gets dryer and cooler the car will run in the 760-790 area with maybe 2-4 percent knock on the punch and maybe 1 percent on the shift. Im running the 93 red chip, with 009's and all the other typical goodies. Like the 93 chip, since it has some timing, but not to much think its 22 degrees in 1st and 2nd, and 20 in third.

Shoebox
 
so in hot weatther just run less alchy and cold weather run more alchy?
 
The problem lies within the chip timing. We have eliminated that problem by adjusting the appropriate areas in the main spark table. The initial retard people get with alky is due to too high timing in the load levels building up to the max load (255). We can easily fix that. But, If you cant make your own chips, you'll be playing the hit and miss game for a long time.. :rolleyes:

Julio, I can help you make a chip to fix the problem. You don't have to run a low timing chip overall, in fact we've been running 24+ degrees with alky and 93, and high boost (23+). You just need to have your chip set up for your car running the lower timing where it's necessary. Give me a call and we'll get together for some tuning. (727)-856-2733.

-Bob
 
Bob how much for an alky chip

Bob,

I met you at dyno day at tunetech. How much are you selling custom alky chips for. Also, do you have the equipment to see what my current chip is programmed for. I need help in tuning this thing as I do not have that much experience in the tuning realm.

Thanx
 
Hey Jeff,
I would be happy to help you out as best I can. I dont sell any chips, just the package you need to make them yourself. However, shoot me an email or call and we can set up a time to do some tuning. We can get some DS recordings and then make some chips to help you get moving faster.
-Bob
 
Bob nice website

Bob,

I like your website, especially the forum. Lots of useful info.
I will drop you a line later this week.


Thanx,
Frank
 
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