16197427 Ability in an S10

[bandit]

I have a 94 S10 CPI 4.3, the pcm i've found is a 16197427. I'd like to top swap out my CPI intake/injection with a syclone/typhoon intake, tb, injection etc. along with the turbo IC system. It's my understanding that the syty trucks are batch fired (each bank) and operate off of one injector driver in the pcm. Can my 7427 pcm control the injectors in the same manner? Does it have two injector drivers? Will it operate off of one injector driver correctly (I've read the syty do it internally of the pcm)? I'd like to keep my 7427 pcm because of my 4l60e transmission, therefore i'm not really interested in running two pcms.

I haven't really jumped into OBD1 tuning, I do a lot of OBDII tuning with HPtuners (LSx cars, L67 V6s, new turbo2.0s, 4.3s) and really prefer it over the OBD1. That said, my GMC typhoon and my 94 S10 both need tunes so I really need to learn it. In the end, I'm bored with my cammed 4.3 CPI in my S10 and really wanna step it up. Being familiar with the syty stuff, and liking the way it works and performs, I'm really wanting to swap it into my S10.

Before I go to far though with collecting parts, I'd really like to understand the capabilities of my stock 7427 pcm. Nobody on the SyTy forums or S10 forums can seem to answer my question. I've cruised this site now for months but really can't find my answer searching and reading around. Thanks

[EagleMark]

If you look through the link below you'll find some documents on converting the 16197427 PCM from TBI to MPFI, it has pictures of removing or jumping the injector drivers in PCM. IIRC it is only needed when doing 8 injecotors, not needed in 6...

Not sure how to handle boost though? There are some codes there to run MAF as well.

http://www.gearhead-efi.com/Fuel-Inj...Information-OD

[Six_Shooter]

I can agree with the desire to not want to run two ECMs, but in the proposed set-up you have, it would be the best way to do it. The '7427 doesn't have a way to deal with boost. The ways to make it work involve the old add-ons of FMU and a way to retard timing under boost, such as an MSD 6BTM. These are compromises at best. Another way to look at that is that instead of adding a second ECM, you're adding other components, in lieu of the ECM.

Adding a second ECM will gain you much better control of the engine than trying to use an N/A program to run in boost. You can then run $59 that will gain you a few things over running the stock $58 code, such as WBO2 fueling control, expanded VE and SA tables, among other refinements.

Another way to deal with this involves knowing assembly code and writing, or patching the code used in the '7427 (Usually $0D), to recognize and make use of the positive intake pressure. This would be the ultimate way to do it, but requires a steep learning curve if you're not already familiar with .ASM code.

You may also want to look at swapping an OBD2 PCM in place of your current PCM, that supports boost. A PCM from an SC 3800 application may do the job, since many of them used electronic transmissions, and the transmission control maybe be very similar to what the 4L60E needs.

[bandit]

Both great responses.

Is it possible then to wire the six injectors off of my existing harness/pcm then? I remember reading through that one link a few months ago, I guess I really didn't pay much attention because of the 8-cylinder emphasis.

My plan for boost control was just to use an external boost controller. I was hoping I could just use the existing NA system to adjust fueling. I know on the OBDII GMs I've been able to tune a 4.3 S10 with a Vortech supercharger using the stock MAF/VE/PE tables and a single stage FP regulator. I had to really work on them and the spark tables, but it seems to be working good. I should theoretically be able to reduce the timing in the tables themselves to compensate for boost right? Won't the stock MAP recognize the added boost?

The idea of being able to run a maf is really intriguing, that would really be cool.

I've looked into possibly converting over to OBDII, my only problem is the engine is in the truck and doing things like changing the timing cover is a real PITA with the 4x4 and dropping oil pan. My front timing cover would need to be changed for the newer OBDII cam/crank etc. sensors. I've done a ton of L67 (SC3800) tuning and would have loved to go that route if I could have.

I guess from what you guys are saying swapping over using two pcms in the best option? That, or pull the timing cover and try going OBDII? Does the PCM i'm currently using need to communicate with the ECM from the syty for the engine?

[Six_Shooter]

The OEM MAP sensor for the '7427 is a 1 BAR MAP sensor and will not read anything above atmospheric pressure (100 KPA), though due to manfuacturing tolerances it may read up to approximately 1 PSIG, but still considered 1 BAR, even if the sensor you happen to pick up can read slightly above atmospheric pressure.

I wasn't talking about boost control, I was talking about fueling a spark control. Open an $0D bin and take a look at it, the VE and SA tables stop at 100 KPA with no multipliers to above that. (OEM OBD1 boost codes, $58, $8F, $31T all used 1 BAR tables with multiplier tables to control fuel above 100 KPA.)

If I were in your shoes, I'd likely go the parallel ECM route, and seriously look into using an OBD2 option, if I really didn't like the parallel ECM set-up.

You would still use both injector drivers in an MPFI set-up using the '7427, the feed back or sense scheme will change and is at least part of the reason the PCM needs modifications to support it.

[1project2many]

Best flow comes from 96+ Vortec heads. Syty intake doesn't fit Vortec heads. Get marine intake instead. Seller on Ebay based in Worcester MA sells them for $200 uses individual injectors.

Parallel ecm system:
http://www.michaelrenz.com/4l80e/

[EagleMark]

Not sure why everyone looks for V8 marine intakes, yeah they are cool, but the ones I seen complete are expensive, and the writes ups have multiple issues? But there's so many Vortec intakes available that have the boss where injector goes. Just have it machined for injectors, guys have been doing this for years.

[PJG1173]

Syty intake doesn't fit Vortec heads. Get marine intake instead. Seller on Ebay based in Worcester MA sells them for $200 uses individual injectors.

Parallel ecm system:
http://www.michaelrenz.com/4l80e/

the sy/ty intake will fit the CPI heads. the intake says vortec but still has the 6 bolts on each side vs the 4 bolts like the 96 and up. its a common upgrade for the sy/ty guys

[1project2many]

the sy/ty intake will fit the CPI heads. the intake says vortec but still has the 6 bolts on each side vs the 4 bolts like the 96 and up. its a common upgrade for the sy/ty guys

Fixed. Wife's blankety-blank laptop deleted sentence. I hate that machine and the hell it puts me through!

Not sure why everyone looks for V8 marine intakes,

Not sure for a V6 application like this,

the ones I seen complete are expensive

Yes, they usually are. It's not like when I found my first setup in 96. These days you really need to search hard to find a cheap one.

But there's so many Vortec intakes available that have the boss where injector goes.

You're talking about carburetor intakes, not stock EFI intakes.

Just have it machined for injectors, guys have been doing this for years.

Sure. Machine the boss, weld in cups if intake's not thick enough, machine fuel rails, purchase / fabricate throttle body, adapt linkage, and still need to buy injectors, connectors, and FPR. It's the same set of issues with more work.

I've had a brand new V6 marine intake in my hands. I don't remember if it had injectors installed but if it did they were probably too small for our intended application. We opted to use the stock 96+ TB and I only remember having to do a little work to make it fit. EGR was a non player but the truck it was going in wasn't going to be subject to testing so it wasn't an issue. The project was never finished so I can't offer suggestions about fuel rail connections etc but there was nothing there that couldn't be overcome.

To the OP...

Turbo applications don't lend themselves to "cheating" like a SC system does. SC boost is tied to rpm where TC boost is tied to load. With SC you can use RPM and TPS values to enable PE mode to cover boost but with TC you just can't make those assumptions.

Swapping in two bar MAP and trying to scale tables can get you into trouble with SD system. You lose idle resolution and if you miss a variable you can invite the Gods of Broken Things to find a place in the engine. Sure, guys do it and some are happy with the results. But it's no less a kludge than installing a second pcm.

The 7749 has two injector drivers just like the 7427. The 7427 has been used with CPI as well as TPI applications. It appears that the right settings will enable a two bank PFI application but you may find yourself doing some experimenting if you go that route. find the injector resistance for the CPI. With the right numbers you could use a 7427 in CPI mode with six port injectors if you still wanted to play around with it.

[bandit]

Thank you for all the replies. I guess as of right now i'm going to just look at going OBDII,then I can use my existing HPT tuning software which I'm familiar with. Although, I'll have to read through the parallel ecm link and see what is really involved.

I like the syty setup because it will bolt onto my L35 heads (CPI), as already stated, otherwise I'd probably consider the marine intake. I just put a lot of time and money in rebuilding and P&Ping the heads, so I'd rather not just dump them.

My plan was to just swap out the map like the syty guys do, I guess that idea was flawed as well though.

With the idea of possibly being able to use a MAF I also thought I could take that route and not rely on a SD tune for control. I guess I don't know enough about the OBD1 stuff to know how they reference VE vs. MAF (when used). Too many of GMs new OBDII systems reference both and then some (L67 3800) cars don't look at VE at all unless the MAF fails.

Thanks again for all the help and insight.