Does GM know how to tune a car??

[omega_5]

Just a note to those that have only done custom power tunes....
OEM's have to tune for the general public, while keeping the government happy.

Their factory tunes must work for the guy in Utah, the guy in California, and the guy NWT Canada.... not exactly like jumping in a car and making it perfect for some guys home town.
As well, they can't just pull/add timing to make a tune work for one extreme, as it effects emissions, driveability and reliability. They rely heavily on the sensors to do their job and balance the vehicle as best as it can for the conditions it is driven in.


So, IMO, yes... GM can tune a car. And the fact that they are able to make a tune that works within their constraints, and suits the vast majority of the public, makes them amazing in their field.

[imphat0260]

Just a note to those that have only done custom power tunes....
OEM's have to tune for the general public, while keeping the government happy.

Their factory tunes must work for the guy in Utah, the guy in California, and the guy NWT Canada.... not exactly like jumping in a car and making it perfect for some guys home town.
As well, they can't just pull/add timing to make a tune work for one extreme, as it effects emissions, driveability and reliability. They rely heavily on the sensors to do their job and balance the vehicle as best as it can for the conditions it is driven in.


So, IMO, yes... GM can tune a car. And the fact that they are able to make a tune that works within their constraints, and suits the vast majority of the public, makes them amazing in their field.

Agreed.....

[PSYKOSTEVO]

I have also seen lots of KR on stock tunes , stock sc 3800's with 5-8 *

stock NA 3800's with up to 10-12*

and my 6.0 stock 2500 hd sees up to 6* - I am gonna license it and fix that one of these days

The 3800 S/c cars have it bad. Really high IAT2 temps. Its a wonder they just don't grenade. But an intercooler added to one makes a HUGE difference.

[kennysabarese]

If you put regular in a car marked premium, usually they still work fine, this is because of the knock sensors right? If this is true then I guess the tune constantly wants to try more advanced timing because it doesn't know if you went from 87 to 93 on your next tank so it has to constantly try to go more advanced.

My LNF Kappa is tuned by Wester's Garage and he's told me that anything under 8* KR won't hurt the engine. I know he's been tuning for a long time, maybe I can trust him?

[Jaxon]

I wouldn't trust that imo, that's quite a bit of knock especially for the lnf. 0* kr is best, 1-2* may be fine but otherwise I wouldn't be running that kinda timing in hoping the sensors can adjust quick enough before your engine is damaged. it may not blow up right off the bat but over time little problems from kr will add up.

[kennysabarese]

I don't have 8, I've never had more than 3* with his tunes. mostly 1-2*

[mkriebs]

If you put regular in a car marked premium, usually they still work fine, this is because of the knock sensors right? If this is true then I guess the tune constantly wants to try more advanced timing because it doesn't know if you went from 87 to 93 on your next tank so it has to constantly try to go more advanced.

My LNF Kappa is tuned by Wester's Garage and he's told me that anything under 8* KR won't hurt the engine. I know he's been tuning for a long time, maybe I can trust him?

Simply put, no. There can be no set point to where the engine will go boom. Like proved in this thread, some cars may see knock more 'sensitively' than others, so say, running 8* knock on car A, might be perfectly fine, because its phantom knock. But, running 8* knock on car B, it might blow up tomorrow.

It is an unsafe assumption to think that your car can handle 8* of knock. In all of my LNF tuning, I have yet to hear actual knock though. And, my boss in his NUMEROUS LNF tunes, has heard it only once, when building a very aggressive tune for one of his close friends. But, that can be taken as a grain of salt, because myself... I would rather be more safe than sorry. You run 8* of knock today, and tomorrow its hotter and more humid, you might see 10* of knock, and KABOOM.

I would not trust that, and honestly, I would change it ASAP. I know Wester does some good work, and he was on the forefront in the LNF game in the beginning, but he is obviously and tremendously wrong here.

[mkriebs]

I don't have 8, I've never had more than 3* with his tunes. mostly 1-2*

Regardless, I would mistrust anyone that stated that anything under 8* of KR is non harmful.

[Iam Broke]

I've seen 4-5* with elevated IAT2's (120*f) and aggressive timing. Backed some out with the intake temp tables so it's not an issue anymore. 1-3* on tip in most days when it's hot & humid. Never heard it knock at all except on a 30psi spike once <3k that scared me enough to never do that sh!t again.

[gmtech16450yz]

I know Wester does some good work, and he was on the forefront in the LNF game in the beginning, but he is obviously and tremendously wrong here.

I have no experience whatsoever with Wester's, so I have no idea what his skill level is and therefore cannot comment on the particular statement he supposedly made.

But...

You guys have to realize and remember not everyone tunes ONLY LNF's. I believe Wester's is a full range tuner, meaning he'll tune whatever his software will support. If so, he's seen logs from lots of different motors, not just the LNF. Let me tell you, the LNF is NOT your typical tuning experience. For example, those of you that are obsessing about making your long term fuel trim stay at 0 and short terms within 3-5 would go crazy trying to do that with any other non-DI motor. Long term fuel trims on a regular port injected motor can run anywhere around -10 to +10 on a stock tune. Put a CAI on and don't tune it (probably 90% of what I see with a CAI doesn't have a tune) and you're looking at +/- 12 or 15 on LTFT's. Don't even talk about short term, using short term instead of long term for tuning only works on motors like the DI LNF where fuel control is so precise.

So... An example closer to the point...

GMT900 trucks (fullsize with 4.8's, 5.3's, 6.0's, 6.2's, '07 on up) show TONS of KR stock. Seeing a log filled with KR as high as 12* is totally normal. (Not saying that's how I would want it tuned) It's obviously ok running like that because having an LS motor in with lower end or piston damage that could be blamed on excessive timing is extremely rare. So someone making a comment like "anything under 8* is fine" would be totally correct.

Now I realize LNF's are a little different, but I've logged plenty of stock ones and they all do have lots of KR. GM even realizes there's gonna be a bunch of false knock on these DI motors because most of the time the LNF's are showing 3* KR, if you look at the timing it's not actually retarding it 3*. It seems like it has to show 3* from more than 1 or maybe even 2 cylinders before it actually drops timing 3*.

So as far as my 2 cents worth, GM has some of the most dependable motors they've ever made showing KR pretty much all the time. I wouldn't jump all over someone that says not to worry about 8* or less ON MOST MOTORS. Seeing as though the LNF doesn't show those levels of KR unless it's REALLY knocking badly, the statement might not be that accurate for the motor he was giving advice on. (Assuming he specifically meant don't worry about <8* the LNF.)

(Oh, I guess I did end up commenting on the particular comment he made, my bad!)

[mkriebs]

I have no experience whatsoever with Wester's, so I have no idea what his skill level is and therefore cannot comment on the particular statement he supposedly made.

But...

You guys have to realize and remember not everyone tunes ONLY LNF's. I believe Wester's is a full range tuner, meaning he'll tune whatever his software will support. If so, he's seen logs from lots of different motors, not just the LNF. Let me tell you, the LNF is NOT your typical tuning experience. For example, those of you that are obsessing about making your long term fuel trim stay at 0 and short terms within 3-5 would go crazy trying to do that with any other non-DI motor. Long term fuel trims on a regular port injected motor can run anywhere around -10 to +10 on a stock tune. Put a CAI on and don't tune it (probably 90% of what I see with a CAI doesn't have a tune) and you're looking at +/- 12 or 15 on LTFT's. Don't even talk about short term, using short term instead of long term for tuning only works on motors like the DI LNF where fuel control is so precise.

So... An example closer to the point...

GMT900 trucks (fullsize with 4.8's, 5.3's, 6.0's, 6.2's, '07 on up) show TONS of KR stock. Seeing a log filled with KR as high as 12* is totally normal. (Not saying that's how I would want it tuned) It's obviously ok running like that because having an LS motor in with lower end or piston damage that could be blamed on excessive timing is extremely rare. So someone making a comment like "anything under 8* is fine" would be totally correct.

Now I realize LNF's are a little different, but I've logged plenty of stock ones and they all do have lots of KR. GM even realizes there's gonna be a bunch of false knock on these DI motors because most of the time the LNF's are showing 3* KR, if you look at the timing it's not actually retarding it 3*. It seems like it has to show 3* from more than 1 or maybe even 2 cylinders before it actually drops timing 3*.

So as far as my 2 cents worth, GM has some of the most dependable motors they've ever made showing KR pretty much all the time. I wouldn't jump all over someone that says not to worry about 8* or less ON MOST MOTORS. Seeing as though the LNF doesn't show those levels of KR unless it's REALLY knocking badly, the statement might not be that accurate for the motor he was giving advice on. (Assuming he specifically meant don't worry about <8* the LNF.)

(Oh, I guess I did end up commenting on the particular comment he made, my bad!)

But it is possible to tune the knock out of an LS series motor, as I have done it on numerous, and still put down excellent numbers. One puts down 410whp, before my last reflash, and the new intake parts, and one, was a GIGANTIC truck (8" lift, 37" wheels) that ran a 15.7 in the 1/4 mi with only headers. Both show a MAX of 1* of knock. But, now you have me curious, just how far we can push the lil G8... lol.

[kennysabarese]

I'm sorry if I turned this thread to a Wester's bashing session. I have some occasional knock, it's not constant through the entire rev range. In my initial tunes there was a little more knock but we've sorted it out. I just asked him what I need to be worried about and he said 8* higher or audible I should be concerned. So I don't want everyone to start saying that he is ok with 8* in all the cars he tunes or something because that is definitely not the case.