Topic: Forced Induction Questions

[wildman4x4nut]

Hi all,
Well I am about to embark on a new project for my SE TJ. I just picked up a used Rimmer supercharger. And since it was used it doesn't really come with a lot of info. And Rimmer is no longer in business.
I have purchased a wideband O2 meter so I can read my A/F ratio & also got a scann program for my laptop so I'll be able to monitor what is going on. From everything I have read so far this should allow me to just about tune the engine without having to use a dyno. I plan on getting the extra O2 bung welded in first and log some N/A runs first. This way I'll know what my engine has been doing to date.

So my first question is this. I just bought the PD 4banger power package from 4WD Parts. So I'll have a decent ignition system to start. But with the added boost what should I run my plug gap at? Narrow it down from .65 to? I plan on using the injectors that came with the blower first and then if I notice any lean conditions I have so lager injectors.
What does anyone think about as far as headers go? Should I install one? What about a high flow cat? If anyone has any experiance with forced induction your comments would be appreciated.

[Jeffy]

Well, I believe you bought the kit from Trailblazer95 who's on the forums.

I'd run the PD system at it's recommended .065" and not .65". There should be no reason to reduce it.  I'd probably get it installed then fine tune it after that.  The Rimmer should be able to run with the stock setup out of the box.

What program did you get?  Does it plug into the ODBI access port so you cna remap the PCM?

[trailblazer95]

yep i'm on here, and he knows how to contact me via email if there's any questions.   i'd just run everything "stock" until you get it set up.  then start tweaking and tuning after that.  you'll find out very quickly that tuning it is a real PITA, so find a good spot and stick with it.  you'll be impressed with the gains straight out of the box.  but hit superchargersonline.com for more info on tuning it, spark plugs, etc.  the 1st cd has the article about spark plugs on it.  they recommend you run 1 degree cooler plug.

[/dev/null]

I'm familiar with a supercharger kit for my other car, so I'll share this-
You'll want to drop one or possibly two heat ranges on the plugs, and gap them down as well. I would go as low as .040-.045. With too big of a gap, the supercharger will 'blow' out the spark. A lower temp thermostat is not a bad idea either, but the ECM would need re-programmed.
As far as the fuel system, most blowers will either re-program the ECM or add a FMU(Fuel Management Unit). What the FMU does, is add more fuel when there is more boost. Otherwise, the engine will run lean and BOOM! About the injectors- I'm not sure what the Jeeps come with, but I would try them out first before upgrading. Not sure about the fuel pump either. It might need upgrading instead of the injectors, 'cause if the fuel pressure can't stay up... Boom!(again).
Just keep a real close eye on the A/F. If it drops, back off. Engine rebuilds although entertaing for everyone else, are not fun for you.

Peter M

[wildman4x4nut]

Thanks everyone for the replies. And yes I have trailblazers contact info so when I get ready I'll be talking to ya.

As far as there being a FCM, this is an older version so there isn't one. And as far as I know even the new Avenger kits don't have one. I have found a piggyback kit that will work on the Jeep from http://www.splitsecond.com but will wait until I have everything installed and running before I get it. As far as test equipment I have spent a little coin on as wide band O2 meter & a OBDII reader that gives live readings & recording capability. So with all that I should be able to fine tune the engine about as good as if I was using a dyno.

I'll be sure to keep everyone posted when I start the project.

[jpcreep]

I am currently using the FTC1 from Split second.  It allows you to calibrate its internal 2 bar MAP using a fuel/timing map which you will have to adjust via a laptop.  a scan tool will be required to see how the ecu is adjusting is fuel mapping.  http://www.obddiagnostics.com/ work very well and is about the cost of one trip to the dealer for diagnostics, but you get to keep the tools.  I'm running an Avenger with intercooler @5 psi.  I did not go the wide band O2 sensor route but use split seconds af meter.