mtuggle86

iTrader: (7)

Ok I got my car tuned its a 01 SS M6 mods are in my sig the tuner was SB tuning in porthuron mi he seems to have a good rep but He do a few things that I find weird and Im just getting a second opinion

First He raised the rev limit to 6400RPMs my car has stock cam and valvetrain I was under the impression that the stock engine was only good for 6200? he said it would be fine so I took his word for it is that true?

The second thing was he used the stock narrowband 02 sensors to tune the A/F

It seems to have more power but Im worried about the rev limit what do you guys think?

jsteele90

iTrader: (13)

6400 is a bit high for a stock cam and valvetrain. 6000-6200 would be better. mine is set to 6500 but i have heads,cam, comp 918 springs and hardened pushrods so it can handle it

mtuggle86

iTrader: (7)

so you think theres a good chance I could over rev it? Thats what has me worried I let it go because he reassured me that the stock valvetrain could handle it with no problem which is against what Ive read here

ItsNotStock

iTrader: (24)

Valve float starts happening around 6,200 on a stock valvetrain. You gain nothing from the extra 200rpm and only risk damaging something when racing. Slap your tuner in the head and then politely ask him to turn it down On my stock engine I personally felt no gain if I shifted at 6,100 compared to just 5,800 so I shifted at 5,800 whenever I got on it. Better safe than sorry.

davidbakergli

iTrader: (1)

^ +1

HTX

iTrader: (1)

just make sure you dont over rev. i owuldnt shift over 6000.

Johnnystock

iTrader: (6)

+1...

Frost

iTrader: (45)

Why do none of you care that it was tuned with no wideband but you get up in arms over the limiter?

mistafosta

iTrader: (9)

I rarely post here, but this was a bit scary. He tuned on a narrow band o2? Those are pretty much 100% useless. I would HIGHLY reccomend you go to a real tuner that uses a wideband setup and a dyno. Have it done correctly, and never go back to this guy again.

6400 is also WAY too high for stock valvetrain, and with a stock cam you gain nothing from shifting up there. Just more possibility of damage.

ItsNotStock

iTrader: (24)

I missed that part. Usually when you see that someone got their car tuned it was done by a professional. He didn't even have a sniffer?

SweetS10V8

iTrader: (4)

How much did you pay for the tune? Did you end up on the dyno?

Sounds like all he did was raise the rev limiter and play with A/F ratio in the Commanded PE tables,and then assumed everything was OK. Did he even play with the spark timing?

Everyone is correct, the stock valvetrain is terrible and goes out of control easily especially if you spin it past GMs settings. There is a reason GM set it where they did. I personally swapped my springs and pushrods before anything, even on my stock cammed engine because of some of the data Ive seen.

mtuggle86

iTrader: (7)

sorry for bringing it back up I paid 275 for the tune It was tuned by S&B tuning in port huron Mi

#1 I was concerned about the rev limiter he said would be fine for sure and to not worry about it Im having him pull it down to 6200 in a few weeks

#2 I was also wondering about using the narrow band 02 sensors because there not known to be good He said he had some good PE Tables to dial in the A/F ratio and it would also be fine

#3 Timing was advanced to 30.5* it showed no knock the car was not dyno tuned it was street tuned

#4 He is a sponsor on Mifbody.com and has a good rep so I took his word on it even tho Im concerned about the rev limiter also the car did seem to drive better and seems to have a decent power increase so im torn Heres there site
http://www.sbtuning.com/index.htm

JonCR96Z

iTrader: (33)

My performance chips offer more gain than proper wideband tuning, and they're cheaper to boot.


You have an incompetent tuner, but the limiter is nothing to worry about.

Do you often hit the rev limiter? I mean if you constantly stayed on the limiter I might worry, but hitting it occasionally won't hurt anything.

I have a 149,000 mile bolt on A4 car and I command my shifts at 6200, I've seen them hit 6400 a few times. My limiter is 6600.



30.5 degrees of timing is STUPID. This isn't a Gen 1 SBC, you don't need that much timing. Tuning timing off of the dyno is a good idea but you need something to tell you that you're gaining or losing power. Such as a drag strip. You'd likely make the same or more power at 25-26 degrees and be way safer.

mtuggle86

iTrader: (7)

I was surprised by the 30.5* degrees also from reading before I got the tune I read 28-29* was where most cars make the most power and are still safe but I have read a few posted where people have gains with 31* advance thats why I didnt say anything about the timing being so high the tuner had a good rep on Mifbody.com thats way I took his word on it but Im starting to worry what the hell he really did to my car it seems to be running better and make more power after the tune what should I have him change? lower the timing and rev limiter?

My car wasnt showing any knock at 30.5* and I always use 94 octane so should I be fine?

JonCR96Z

iTrader: (33)

People like to push timing to the point of knock. Like I said if you made the same power with 25 degrees of timing (which is likely), why go any higher. You just run more risk of detonation if you get some bad gas or something.

That's why tuning timing at a track is best. You put the real load driving a car on the engine, instead of turning a roller on a dyno. You can find the upper limits and then pull timing until power starts to drop off (or MPH at the drag strip).

Making power isn't about how much timing you can get, its about getting the right amount. There is a nice thread by JRod around here somewhere that is very informative about timing.

You'll be alright with what you have, that's the reason they make knock sensors. I would just try to find another tuner and see what his opinion is on what you have/need.

Silver98Formula79

iTrader: (17)

So what kind of numbers did it put down before and after your "tune"?