New to tuning.

[Steven LS1 Z28]

I’m new to tuning and looking for some direction. I have a 98 Z28, with an LS6 intake, long tube headers, off-road y-pipe, B&B cat back, and SLP cold air intake. I know that I am running rich due to the soot on the exhaust tips and the smell of the exhaust. Any advice on where to start with my tuning?

[Supercharged111]

I seem to recall the F bodies commanding more WOT fueling than the Corvettes and also having less ignition advance. At least on the stock tunes I'd looked at years ago. Do you have a wideband? Your best bet would be to tune the VE/MAF then command a WOT AFR of something more akin to 12.7-13:1 vs the factory pig rich settings.

[statesman]

Your best bet would be to tune the VE/MAF then command a WOT AFR of something more akin to 12.7-13:1 vs the factory pig rich settings.

I don't normally challenge the advice you give, but this time I have to. Seriously, 13.1 AFR at WOT? In my opinion that's too lean... and considering you don't even know what fuel he's running, it could end up putting him in a situation where he gets very little enrichment at all.

[Steven LS1 Z28]

I do not have a wide. I use only 92 or 93 octane unleaded.

[Supercharged111]

I don't normally challenge the advice you give, but this time I have to. Seriously, 13.1 AFR at WOT? In my opinion that's too lean... and considering you don't even know what fuel he's running, it could end up putting him in a situation where he gets very little enrichment at all.

Sorry, I was assuming premium fuel here as that's what the car calls for. 13:1 is the number I have seen slung around for the LS1 by folks with dynos. If you've observed otherwise I'm open to more input. In the absence of a wideband dude is dead in the water. I think we can all agree that 12.5:1 is a universally safe AFR for an NA engine though.

[ScarabEpic22]

First step is to buy a wideband, without one, you're shooting in the dark as far as what your actual fueling is.

The 97-98 PCMs are super limited and you have to deal with a Secondary VE table plus there are limitations around running SD as well. The later 99-02 512kb PCMs don't have this limitation and it's a pretty quick swap if you need more tuning support and functionality.

[statesman]

Sorry, I was assuming premium fuel here as that's what the car calls for.

Yeah, I guessed that was your logic... but people will use shit fuel if that's the only fuel available in their area. I never assume what fuel is being used, I always ask.



13:1 is the number I have seen slung around for the LS1 by folks with dynos. If you've observed otherwise I'm open to more input.

I'm observing a newbie who doesn't even have a wideband yet, let alone a dyno. I would suggest a newbie (with a wideband) shoot for 12.2 or 12.3, and a more experienced home tuner should shoot for 12.5 or 12.6. Personally, I think 13.1 is too lean even for an expert dyno tuner... but that's just my opinion.

[In-Tech]

Good call statesman,
The overlap cycle has a lot to do with what the wideband sees. There is no magic AFR/Lambda number

[Steven LS1 Z28]

Ok next question. Any recommendations on a good affordable wideband and where to install it? I have read on other forums driver side or passenger side, with no real consensus on where.

[Supercharged111]

Yeah, I guessed that was your logic... but people will use shit fuel if that's the only fuel available in their area. I never assume what fuel is being used, I always ask.




I'm observing a newbie who doesn't even have a wideband yet, let alone a dyno. I would suggest a newbie (with a wideband) shoot for 12.2 or 12.3, and a more experienced home tuner should shoot for 12.5 or 12.6. Personally, I think 13.1 is too lean even for an expert dyno tuner... but that's just my opinion.

You bring up good points, in addition he'd be smart to leave some wiggle room in there in case he misses something when he does get it tuned with a wideband. If memory serves correct, the stock PE AFRs commanded were well into the 11s.

Steven I have an AEM gauge in my 1500, I want to say I only paid around $125 for it back in 2009. It has a couple wires that allow you to make a serial cable for it to get it talking to the Flashscan.

[In-Tech]

Ok next question. Any recommendations on a good affordable wideband and where to install it? I have read on other forums driver side or passenger side, with no real consensus on where.

14.7.com is a very affordable wideband. keep in mind the 0-5v is all that matters. or .5-4.5

[Supercharged111]

14.7.com is a very affordable wideband. keep in mind the 0-5v is all that matters. or .5-4.5

You talking about these guys?

https://www.14point7.com/pages/products

I'd forgotten all about them! While the AEM has gone up in price since I got mine, it is running the newer 4.9 sensor.

https://www.amazon.com/AEM-30-4110-UEGO-Ratio-Gauge/dp/B00N3VGPYS

I also have an older Tech Edge in the dually, but I blew my wad on that because the standalone I was running at the time didn't have any sort of datalogging capabilities. The wideband does though.

[joecar]

Several points:

I agree on swapping PCM to part # 0411 and running OS 12212156 (with matching trans segment).

For street usage, experienced tuner will run WOT at around AFR 12.6 which will be safe for the motor. I agree that a novice tuner should run WOT AFR 12.2-12.3 since this gives a greater error margin (err on the side away from distaster).

The WOT AFR 13.0-13.2 that you see mentioned in various places is only set by running on dyno and observing power increasing (slightly) as rpm continues increasing above where peak torque occurs, and is done only when spark knock is absent. This is done very carefully on the dyno. (Note that peak torque is a special point, this determines how to set WOT fuel/air and spark advance).

With mods being LS6 intake and LT headers you can probably run the stock 2002 F-car 12212156 tune and see how it runs (using a wideband).

[Supercharged111]

You're right, it was a seasoned Dyno tuner that said they like 13:1.