Who has gotten their Knock Retard to 0*?

Tooky

Tooky

Serious about performance
I only did a few times and it seemed to be "blue moon" type unrepeatable situations. If you have a truck you could get to 0* KR on pump gas and the stock chip (or T1-15/T1-16 on the Ultimate), how did you do it and how difficult was it?

I have seen some trucks that I swear have done everything in the book and they still get knock on pump gas, and I have also seen some trucks that didn't do much at all and they get CONSTANT 0.0 knock on a run.

The reason I ask is, my truck of course still has the 3-6* knock on pump gas and I need to resolve that before I can continue tuning my truck. I've done all the recommended stuff and I'm not sure if it makes sense to beat my head against a wall doing it all again or if I should just "give up" at this point? What do you think? I know I have gotten good performance out of the parts I have WITH the knock still happening, but I feel it could go even faster still if I can elimininate that knock to 0.
 
Merk

Merk

Donating Member
Josh,

I have zero knock on a stock truck.

Its because of:

Trial and error
Regular maintenance
Tits and ass
Beer and Bourbon
________
Uruguayan recipes
 
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K

kwick6

Donating Member
You can do all the stuff you want, and probably still end up with a small amount of knock.

The stock turbo is out of its efficiency range around 12-14psi, and trying to run 16-17psi on pump gas is pushing it... it just generates to much heat.

I have the te44 and have run 15-17psi with no knock. I might get a few degrees when the converter locks, but thats about it. The knock went down from 8-9 degrees to 3-4 just by changing turbos. I'll be putting on an external WG this spring, and then I should get solid boost and find out where the limits are.
About the best you can do is find out when your truck knocks and pull a few degrees of timing out... so that means getting the chip custom made to your truck. I don't think there is any other way.

Later,

Scott
 
S

Sy#26

New member
Make sure your base timing is indeed @ 0° - if you're getting 3-6° of knock, only takes a degree or two in base timing advance to cause that. See archives about vibration damper slipping on the crank pulley hub. Check it out.

Barry - Sy#26
Bangor, MI
(Running 22psi & 93 octane w/o any KR....)
 
Tooky

Tooky

Serious about performance
Sy#26 said:
Make sure your base timing is indeed @ 0° - if you're getting 3-6° of knock, only takes a degree or two in base timing advance to cause that. See archives about vibration damper slipping on the crank pulley hub. Check it out.

Barry - Sy#26
Bangor, MI
(Running 22psi & 93 octane w/o any KR....)
Click to expand...

Barry, I tried retarding my timing by as much as 8* this fall, and it did not have a very direct, significant effect on my knock. It might have lowered it a little but certainly did not eliminate it. Although I will say the truck definitely makes more power at -1* base timing than it does at -8* timing. Probably because the knock is about the same but the total timing is going to effectively be a lot higher on the -1* base timing setting. I set the truck to "0*" base and it knocks worse than ever. I'm gonna have to set it back to -1* and do a TDC check over winter. But the fact that even -8* base didnt solve the knock, convinces me that my knock problems do not lie in the base timing.

PS: Is your 22 PSI & 93 octane accomplished with alcohol injection, or what? No sense in "teasing" us without an explanation... ;)
 
SeattleSy#1255

SeattleSy#1255

Category 5 Conservative
I agree with Scott...Stock turbo can become inefficient when pushing high boost from what I have seen. I also think that sometimes unless the ultimate is completey custom to your truck, that will give you knock as well. Are you getting that with the alki??...that should help.
 
S

Sy#26

New member
Ok, excessive timing was my first thought, seems you're on top of that. How about MAT? Everything in the IC system working well? EGR system working correctly or removed? Is it all fuel dependant? There's some crap gasoline out there; local station was selling 89 as 93 recently. Is there any relation to RPM? I'm thinking false knock @ a particular RPM. Is it the same when you run a lot higher octane in it?

My 22psi on 93 octane is with 20% (realtive to fuel) 1:1 methanol / water injected. TE60 compressor, 1996 heads, modded IC system (standard recipe there). MATs run around 20° above ambient temperature. Around 12° timing @ max boost. Over 600 PROM images tried so far, which is part of getting there. In all honesty, I normally run only 20psi - and - I'm on my third engine in the last twelve months......

Barry - Sy#26
Bangor, MI
 
E

E-Rue

New member
tookmeister.....did you ever get your downpipe bolted back to the trany case? if not........shame on you!

e
 
P

phoonerorlater

Active member
I got 0 knock.

1. I drove to pheonix with a friend.
2. I wrote a check for $16k
3. I drove to sean morris' shop one day and ran DM with him.
4. DM came up with 0 knock
 
Tooky

Tooky

Serious about performance
Sy#26 said:
Ok, excessive timing was my first thought, seems you're on top of that. How about MAT? Everything in the IC system working well?
Click to expand...
You betcha. MATs follow air temperature but in the cold weather they are always below 100*F until the very end of a quarter mile.

EGR system working correctly or removed?
Click to expand...
GM EGR blockoff plate, didn't make much of a difference. I cleaned the throttle body and upper intake manifold of any oily residue. No change noted, really.

Is it all fuel dependant? There's some crap gasoline out there; local station was selling 89 as 93 recently. Is there any relation to RPM? I'm thinking false knock @ a particular RPM. Is it the same when you run a lot higher octane in it?
Click to expand...
I've run lots of different brands gas (all 93), nothing significant noted. I cant say about a relation to RPM. I can email you some DataMasters if you like. When I run higher octane the knock goes down, but only if the higher octane is significantly higher. For instance when I ran 98 octane the knock was about the same. When I ran 101 octane the knock hit 0.

My 22psi on 93 octane is with 20% (realtive to fuel) 1:1 methanol / water injected. TE60 compressor, 1996 heads, modded IC system (standard recipe there). MATs run around 20° above ambient temperature. Around 12° timing @ max boost. Over 600 PROM images tried so far, which is part of getting there.
Click to expand...
22 PSI, that's fantastic. What do you think is a realistic estimate for my max boost on denatured/water injection using SMC alcohol kit, stock turbo, stock (L35?) heads, standard stock IC mods? I was hoping for 20 PSI but I'm thinking it may be as low as 17-18 PSI :( I mean, once I get my truck's ailments fixed. Thanks.
 
Tooky

Tooky

Serious about performance
E-RUE said:
tookmeister.....did you ever get your downpipe bolted back to the trany case? if not........shame on you!
Click to expand...
No the truck is stored for the winter, I'm just working on it in the meantime and collecting ideas to try out in spring (or parts to install/replace over winter).

I looked at that downpipe bracket, its way too stiff and far away to be bolted to the tranny! Then I looked at the 1991 teal-green GM service manual supplement and it seems there is some type of a hand-sized little bracket piece that I don't have. Is that what connects the tranny bolt to the downpipe? If so, that would make sense. I dont think it would be possible for me to "stretch" the downpipe over to mount that bracket directly to the tranny. But I got the stock turbo out now, so now would be the time to try. My stock cat and ATR exhaust is all still bolted in though, and the DP doesn't have much play.

I dont think it's that downpipe though, I mean why would the knock reduce on high octane then.
 
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