Bowtie Brody's Namesake 96 454

[Christian Steffen]

I think it has to do with the distance from the valve to the injectors. The 454's are further towards the centerline, the 350 spider injectors sit pretty close to the port.

@BNielsen , if you're in the mood for it next time we meet up for some tuninig I'd like to do some back to back logs with your truck with both injection timing setups. Maybe your average trims or injector duty cycle will change slightly? There may be some benefit in drivability. I like the way mine responds anyways. Yours felt fine when we drove it with the "new" tune, but not being in the driver's seat I can't tell what's going on.

I also forgot to tell you Brody that the idle speed and timing that I run is actually due to me fiddling with the spark advance and idle speed like a carb'd car. I messed with them both until it made the max amount of vacuum and ran smooth. Then I blended all of my tables to stay at those values until moving. I believe I also did it in gear as well.

That would make sense.. I guess I should probably experiment some more too. It will definitely show on stfts or a wideband when you're making progress, trying to make it end up richer so we can pull some fuel.

Brody it sounds like you're making progress.

 

[BNielsen]

That would make sense.. I guess I should probably experiment some more too. It will definitely show on stfts or a wideband when you're making progress, trying to make it end up richer so we can pull some fuel.

Brody it sounds like you're making progress.

I'm trying to make progress, once I get some maintenance out of the way that I've been putting off I can get a wideband, AFR gauge, and HPTuners ordered; so hopefully by late May I can make something happen.

 

[Mangonesailor]

From what I've found, the speedos in these trucks aren't really accurate anyway.. I go by the speed shown by the PCM in HPTuners scanner, which IS dead on with my GPS for the most part - but my speedo reads almost 4-5 higher. I could just pull the needle off and reposition it, but it's probably more trouble than it's worth.

Those are adjustable separately. You do the trans revs per mile to get the reported speed in HP tuners correct and so that you can get your shifts setup correctly. THEN the "VSS pulses per" Cal to get your speedo calibration correct.

 

[BNielsen]

Those are adjustable separately. You do the trans revs per mile to get the reported speed in HP tuners correct and so that you can get your shifts setup correctly. THEN the "VSS pulses per" Cal to get your speedo calibration correct.

I might have to have that checked next time we meet up; PCM of NC emailed me the other day asking if I was still wanting to schedule an appointment, which if I get HPTuners and my AFR/Wideband set up I reckon I won't need to bother with that.
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Ordered a dizzy for it tonight, an Accel shaft because it was cheaper than a Summit or D.U.I. distributor,

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[Mangonesailor]

PCM of NC emailed me the other day asking if I was still wanting to schedule an appointment, which if I get HPTuners and my AFR/Wideband set up I reckon I won't need to bother with that.

I would hold off on a Dyno tune until the VE and MAF tables are correct. That provides you with all of the drivability on the street first. I would get that done first though so you have a good baseline to give them so when they run it on the dyno.

Dyno runs are them running for a baseline, adjusting fuel or spark either run and testing result, and doing it again and again until it's safe and making max power. But, you need to have your MAF tuned so that the engine is actually creating the correct demanded AFR so if you play with the PE table it's "set and forget". It should make their process quicker. Their FAQ on a trailblazer forum says they don't lock their tunes, so that's badass. https://tbssowners.com/forums/pcm-nc/91217-pcm-nc-faq-thread.html

Sounds like though they also take care of part throttle stuff. Idk. It may be the better option. How'd the convo go with them when you talked about getting your truck done? Did they mention what they would take care of?

 

[BNielsen]

I would hold off on a Dyno tune until the VE and MAF tables are correct. That provides you with all of the drivability on the street first. I would get that done first though so you have a good baseline to give them so when they run it on the dyno.

Dyno runs are them running for a baseline, adjusting fuel or spark either run and testing result, and doing it again and again until it's safe and making max power. But, you need to have your MAF tuned so that the engine is actually creating the correct demanded AFR so if you play with the PE table it's "set and forget". It should make their process quicker. Their FAQ on a trailblazer forum says they don't lock their tunes, so that's badass. https://tbssowners.com/forums/pcm-nc/91217-pcm-nc-faq-thread.html

Sounds like though they also take care of part throttle stuff. Idk. It may be the better option. How'd the convo go with them when you talked about getting your truck done? Did they mention what they would take care of?

They didn't mention any specifics, how much more needs to be done to get the MAF and VE tables corrected?

 

[Mangonesailor]

They didn't mention any specifics, how much more needs to be done to get the MAF and VE tables corrected?

EDIT: Looks like they do it all... driveability and Dyno

So maybe they also do the VE and MAF? Might want to ask. Could ask as well if it's worth the time to them for it to be done or more closely dialed in before they do the dyno runs.

 

[Supercharged111]

I've been lazy on mine, just bumped the VE table 5 or 10 percent so my LTFTs are negative single digits. I really need to hook up the wideband to see what's happening WOT.

 

[AK49BWL]

Those are adjustable separately. You do the trans revs per mile to get the reported speed in HP tuners correct and so that you can get your shifts setup correctly. THEN the "VSS pulses per" Cal to get your speedo calibration correct.

Gotcha! I've had HPT for well over 2 years tuning my 97 with its 0411 now and I'm still learning new stuff lol. Like this talk of injector timing, I've never messed with it at all, but seeing y'all talking about it makes me want to mess with it

 

[BNielsen]

Haven't done much lately because the truck really doesn't need much; my mechanic said he didn't feel comfortable trying to replace the dizzy without pulling the intake.
Which if it does come down to it and he needs to open the intake up, I'll probably have some different injectors on stand by; anyone got any suggestions?
I do need to give the truck a complete fluid service, it's long past time for that I think.

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