Whipple Supercharger on GM 5.7 TBI Truck engine

[Curtis-226]

I am new to this site and hope you guys will be able to help me move forward with my build. Maybe you guys can point me in the proper direction.
I have a 92 c-1500 with a tbi 5.7 (pretty standard) but it has a full Whipple 1.6L Supercharger. It has the stock "Whipple" prom but I have upgraded my cam to the 96'-98' Vortec truck cam and also converted to a full roller setup. Stock will run approx 6-7psi but I would like to spice it up to 8-10psi if possible.

My issue now is I need to tune the Stock OBD1 ecu. Ideally I would like to upgrade to OBDII for ease of tune ability and live data logging etc.

My question to the group is will the OBD1 system be able to effectively compensate for boost/ or even read positive pressure? I know its been done in the past with the Prom from Whipple but is that a work around/ cheat for an OBD1 system to compensate for the boost via mechanical components? (Down stream Fuel psi Reg to raise psi after the OEM Psi Reg in the TBI Housing)

Or would it be ideal to graph a OBD2 into a TBI system? I am limited to a OEM style TBI Housing due to the mounting constraints of the Whipple.

Which area in the forums be best suited to these types of questions? (I Hope I am in the correct place to start)

Thanks in advance and look forward to your responses.
Curtis.

[tayto]

If you are not running a 4L60E or 4L80E and have no plans too EBL may be the way to go. http://www.dynamicefi.com/EBL_Flash.php handles up to 30psi of boost and a laundry list of other features. I have one for sale if you are interested.

[1project2many]

My issue now is I need to tune the Stock OBD1 ecu. Ideally I would like to upgrade to OBDII for ease of tune ability and live data logging etc.

I'm not sure I would go through the work of using an OBDII controller. I would likely switch to a 94-95 16197427. Datalogging speed is more than sufficient for most projects, real-time emulating is easy to accomplish, the ecm will control an electronically shifted transmission, the code is well documented and relatively easy to modify, there are multiple tunerpro tuning and datalogging definitions available, there's a MAF (instead of MAP) based calibration, and it was used in similar trucks in 94 and 95 making stock parts available.

The ECM can "read" positive pressure but it's not really programmed to understand it. Manifold pressure is measured by a pressure sensor which uses a 0 - 5V range. Most stock sensors read from vacuum to 14.7 psi pressure absolute (no boost, no vacuum). The next step up is a 2 BAR sensor which can read vacuum to 14.7 lbs positive pressure. This sensor also uses 0-5V scale just like the stock sensor. So the ecm will read it, but it won't know that it's measuring greater pressure in the manifold. For a turbo it can be very important for the ecm to be able to accurately read pressure but a supercharger is tied to engine speed so it's possible to lie to the cm. You just need to keep track of what you're saying.

Have you picked up any tools yet? It is possible to extract data from the Whipple chip to determine what changes they made. That often provides clues for making your own modifications.

[mira9_cz]

Hi Curtiss226, I have the same job upcoming too. I scored two of those small TBI whipples at ebay, one for my Caprice and one for my Astro Van. But it will take me long time appearently, now with that stupid virus I can't even find a machnie shop to bore over the block, I'm in Europe.

Anyway I have read through a lot of history threads and this is what I found out for the whipple kit: Some preffer to stay with 427/625 because it is well documented. It is, but to lie to the ecu is the approach here as 1project2many stated. 2 BAR sensor and following many different threads here and thirdgen forums seems like the best way to me. Other members asked the same questions before and going this way means you will have at least some support. Then some other people recommend EBL Flash because it was designed with boost applications in mind. Sounds good too, but my PERSONAL opinion is that the basic bin you will get with EBL Flash won't be effortless too. And since in this you really need to know what you are doing the effort with EBL Flash and 427 will be about the same. I think with EBL Flash you can not use TunerPro masks or some other compatibility issue was hard stop for me. Point is that going EBL Flash you will become uncompatible with many many usefull threads for unmodified ECU's. OBD2 seems like wrong way to me, you will still need to know what you are doing. Only the tools will be more compatible and user friendly, maybe more to choose from, but in principle you will mess with one more trouble (OBD to OBD2) and then you will stand before the same pickles as before. But at this moment you already you spent thousands.

I remember I saved some useful links for this project into bookmarks, here they are.

TBI, Tune, Engine Mods, Boost! - http://www.gearhead-efi.com/Fuel-Inj...php?t-501.html

PCM Options for Supercharged 454 / 4L80E - http://www.gearhead-efi.com/Fuel-Inj...php?t-501.html

16197427 Ability in an S10 - http://www.gearhead-efi.com/Fuel-Inj...hp?t-1701.html

Do you have some knowledge how to read chips already? Please consider buying moates.net GM OBD1 stuff, I really need you to ready your original whipple chip :-) That chip is really rare item! It would help a lot to everyone of us to find out what exactly whipple did to stock config.

Me myself I have ordered custom bin from David from Powertrain, the guy who worked for whipple back then when then made these TBI kit superrchargers. He made me Whipple compatible bin from the bin I read from my 5.0 caprice (965 ECU). I paid him and it was only one or two years ago. I feel it would be criminal behavior from me to send that bin online for everybody. I respect David's work and it would just be wrong. Unfortunately to learn myself from the bin, well, I'm not that skilled to see what he did in HEX. $62 mask is not very well documented and many parameters David changed are not described in the mask (I compared original and his with compare tool of tunerpro). But I'm opened to discuss that bin with somebody who will not post it online and will help the community to describe what needs to be adjusted for Whipple TBI supercharger, without posting Dave's work online of course.