Questions.....using 93-95 3.4 for rockcrawler install....

[Conn]

I'm set on using a 3.4l from a 93-95 camaro for our rockcrawler project.

I've been told that i can use the 93-95 SFI 3.4 engine (OBD I i'm assuming) in conjunction with a 3.1 computer from a Beretta or similar, but some alterations will have to be made to the camaro wiring harness.

I'm decent with wiring, troubleshooting, etc, but i'm not sure where to start or what will work? Are my assumptions of the engine/ECU combination correct?

What, if any, alterations will need to be done to the wiring harness? Should the beretta harness or the camaro harness be used?

I'm looking for the best performance, so will injectors, or any modifications to the ECU be necessary?

I'm a little lost. I guess I'll "rephrase" myself....

If i want to use the 3.4 from a 93-95 camaro in a rockcrawler....

What's the best harness/ECU to use and what modifications will I need to undergo?

Thanks.

Conn

[WhiteRaider]

SFI is nice at low RPMs where you will be rock crawling. Necessary, no. Nice. Yes. Benefits, a very little.

The 93-95 3.4 Camaro ECU is the only stock SFI ecu for that engine.

Why don't you just use the harness from a Camaro? That would be the easiest way and would require the least amount of modification by far. You would need a VATS bypass module which are easy to find and cheap nowadays.

Now, if you want to be able to tune your computer, I don't think the 93-95 ECU is your best bet. It's not as easily tuneable as the 7730 ecus - however, they are not SFI but MPI.

If you want a tuneable SFI computer, the ECUs from the 3.1l SFI Buick Centurys and Cieras are tuneable with Tunercat. Their definition file is $20 and the program is $70 or $80, but there is a fully functional trial version.

A few Isuzu guys have put the 3.4l in their Troopers and used the harness and ECU from a Camaro/Firebird. It works great for them and this would be my recommendation to you unless you want to do some home tuning. The wiring harness is already in a RWD configuration which it would not be on the 3.1/3100 FWD engines and it is already tuned from the factory for that engine. It probably won't be completly optimal for your configuration, but would work good enough for most people.

If you want easiest to tune, I'd say get a 7730 ECU from a late 80s/ early 90's 3.1l Cavalier and yank the entire wiring harness. Beretta, Corsica, etc. are pretty easy wiring harnesses too. Get the wiring harness and ecu from the same vehicle to make your life easier. It's MPI, but that's not really that big of a deal.

Is this a manual xmission vehicle? If not, make sure that your xmission does not need computer control. If you are using a 4l60E transmission, then it could be controlled with the Camaro ECU from an automatic, but other than that, you'd have to figure something out.

The disadvantage to using the Century ECU is that it is a MAF only ECU. The 7730 ECU or Camaro is MAP only. MAFs are more fragile than MAPs and don't handle the constant jarring, pounding, and vibration that rock crawling would cause as well as a MAP. They are also much more expensive to replace than a MAP. Not a huge deal or something that will break a lot, but it is something to consider for this swap.

Depending on how many mods you want to do to your engine and if you are interested in tuning should guide your decision. Easiest would be a Camaro harness because it's already setup for your engine and the sensors that are in it.

Anyway, sorry about the ramblings. This is something that I've thought about a lot for my swap into my 4x4 Raider.


[Edit - absolutely easiest configuration, convert it to a TBI setup like an Isuzu Trooper 2.8 or an S-10 2.8. Pull the wiring harness, ECU, intake manifold, and TBI unit. This would be the absolute easiest setup.]

[sharkey]

id say your best bet would be the camaro pcm/wiring. itll all plug right in, no tuning required. make sure you get it from a standard tranny car though, if the computer doesnt see the electronic tranny hooked up to it, itll go into limp mode. the other option would be to get the 3.4l motor and 4l60e auto tranny, and the auto pcm/wiring. this would work very nicley if you are running an auto. it has the same dimensions as a 700r4.

BTW: what kind of vehicle is this going into??? what would the original powertrain have been??? or is it a custom build???

[BMC]

Conn,
I like what whiteraider wrote. Good stuff. For almost every conversion i have completed, we have used the stock 93-95 Camaro PCM with the 3.4L motor. Easy and a good system for our MGB conversions as well as my 3.4L SFI powered S10. We did one haltech conversion and for the most part, would reccomend MOST people to stick with the stock PCM for their application. The Haltech was installed for a future big cam, possible compression or a supercharger which was never installed.
The SFI system that comes with that motor is fantasic and these motors make good torque everywhere. Some day... i will update my website with more information, but then i have said that for a few years now! :-)
-BMC.

[Conn]

Ahhh....

MUCH THANKS for all the info.

I knew there was a VATS module to disable on the camaro PCM, but i wasn't sure if it was worth the hassle. looks like they are pretty cheap.

I knew there were advantages and disadvantages to each, but wasn't clear. thanks so much for the great info.

The transmission is a tricked chrysler 904 from a mid 80s 2.5 or 2.8 jeep cherokee. it's non computer controlled and will bolt up with no adapters to either the D300 or the NP231 transfer case. This one will be in front of the Dana 300. My whole goal was to keep it simple and cheap with no adapters.

We had used a 3.5l from an olds aurora before and got a harness and computer from turn key engine supply. The engines are CHEAP ($400) but the computer and harness is around $1200, which quickly moved me away from the shortstar 3.5 motor. And you have to monkey around with alternator mounts and cooling issues from what I recall. A SMOKIN little motor though. It had custom headers made for it which made a tremendous difference.

This is either going into a 94 wrangler tub that i have sitting here, or the beginings of a tube chassis. I sold my last built wrangler because it was to the point where i needed to start cutting on it, which i didn't want to do. I'm not sure which vehicle it's going in, but i wanted the engine, trans, and t-case sitting here in the floor, turn key ready to go when i decide.

I'll be back for more questions i'm sure.

Conn

[Conn]

looks like the computer i'll need is 16196397?

i pulled it up on car-part.com and kinda confirmed it here:

http://www.enginecontrolunits.com/catalog/CHEVROLET_CAMARO/1994.htm

but it looks like the same ecu was used for M/T 3.4 camaros, skylarks, grand prixs, berettas, monte carlos and the like.

even though some of these cars are A/T, i guess as long as the #s match, i'm good.

i need to find a complete car somewhere and gut it. most of the yards around here pull the computers and throw them on a shelf though.


wow, these 3.4s are only kickin' out 160 HP. i wonder how much trouble it would be to go ahead and dig around for a supercharged 3.8?

[WhiteRaider]

If you're considering engines like the SC 3800 and the Aurora, engine mounts probably aren't going to be a problem for you. Why not get a 3400 or a 3500. You can get low mileage engines for a few hundred dollars. The aluminum top end is nice for weight savings and they are reliable engines. You can use a lot of the 3.1/3.4 or 3x00 computers too.


The 3.4 has a lot of low end torque which is what you need for rock crawling. Put some roller rockers on there, port the intake, get a valve job, and put some headers on there and you'll probably get over 200 HP.

On a rock crawler, top end speed most likely isn't a concern. Low end torque is the key. Throw in a low/mid torque cam like the HT Crate Engine cam or the Mellings MTC-5 (MPI only - cannot use the Camaro ECU) and you're more than set. The Isuzu 4x4 guys are incredibly happy with their 3.4 Camaro engines.

[BMC]

The Camaro has a flat torque curve which i think is pretty nice for our cars, and probably still very good for your application. Keeping the stock PCM is the way to go for most.

I know that the 2.8L Jeep we did with the automatic had to have the Jeep flywheel being of a bit different bolt pattern to the torque converter. So, you will need a flywheel for a 1985 Jeep Cherokee then you will need to have the flywheel zero balanced- pull the weight off one side and have it balanced by a machine shop.

[Greg55_99]

Chris Pomeroy sent me this pic of his Buick 3800 V6 hooked up to a Toyota R150F with dual cases. Nice.....

http://www.jeeps-offroad.com/attachment.php?attachmentid=6260

Greg