I am looking for (as soon as I can sell my 2002 z28) an M6 lt1 z28. I think I want to stay away from the 93 speed density. 94 and 95 (does 95 have an OBD 2 diagnostic port?) are OBD1 right? Is this harder to tune or will it cause me any problems? What years have the vented opti and is that something I should worry about?

It is going to be a heads and cam motor built to handle a 200 shot (the driveline will be appropriatley upgraded). I did a search but could not find any definate answers. I just need to know if there is a good reason to stay away from certain years. My main concern is that I go with a computer that is easy to monitor (I don't know what is used on OBD1 pcms) and tune. Any help is appreciated.

Dustin Keers

 

It's a lot cheaper to procure editing software for OBD1 (ex. "LT1_Edit" or "Tunercat") than it is for OBD2. With that in mind, I'd stick to a 94-95 considering your intentions. You could also buy a 96-97 and convert it to OBD1 for about $250. LT1_Edit is available for OBD2 and is around $550, and there may be other hidden costs there too.

 

94-95

 

94 has the non-vented opti, 95 is vented. 95 is OBD-I but has an OBD-II style connector, so it confuses a lot of people. You can use Diacom to monitor it, and LT1Edit to change it. OBD-I is much more user friendly when it comes to modifications.

 

I prefer the 93 because I don't have to mess around with some things like the MAF and there's a few other things missing that make it easier to work on. However, then you have to deal with having to purchase different headers (air fittings different), you have to use the more expensive non-vented opti and you have to deal with a different type of PCM.

I would go with the 95 because it's dual exhaust and has ODB1.

 

I'm going to piggyback on what DJArcadian said. The 93 isn't something that should be ignored just because it's speed density. Having a chip burned isn't that big of a deal, and the little nuance of having to deal with the different air pipes on the headers isn't anything to fuss over. The non-vented opti situation isn't the best, but if you're going to do a head/cam package, or even swap the cam, it's not that difficult to buy a vented opti, timing cover, better timing chain, and wiring and vaccuum harness'. A lot of people say the 93 models run stronger, and repspond better to mods than the other years. That's somewhat up in the air, but I've seen a few really well running 93's.

That said, if you're hell bent on staying away from the elite and only year speed density LT1 F-Body , I'd say go with the 95 for reasons stated above.

 

Ok, I won't rule out a 93, but if I find one I will just make sure it is a great price. Does the 93 have a different 6 speed transmision than the rest? I think I am going to look for a '95. Does anyone want to trade their 95 that needs some work for my 2002 z28? (with cash of course ) Thanks for all of the help so far.

Dustin

 

a 97 has the same interior styling as your 02 does. the only downside(if you can call it that) is that its OBD2 so if you were planning on mods that call for computer modifications then its going to be more costly than say a 95(OBD1). but even that isnt really a factor to consider since you could always replace the OBD2 with an OBD1 in about 5 min. the 97 is the last year of the LT1 so several problems you find in the previous years are not present in the 97. basically i would stay way from a 93-94 unless you found a really good deal on one.

 

Is yours in the for sale section? How much do you want for yours? Color? Tranny? Mods? Thanks. By the way, the 94's are very strong cars. I have about 151,100 miles on mine, bought it with 119,000 miles on it. Other than the usual things that go, only major thing i've done is have the head gaskets replaced along with the starter. Not too bad, aye?! (knock on wood )

Ryan

 

The 93's had two different six speeds. Coded M28 and M29.

Gear Ratios:

M28 M29 94+
3.36 2.97 2.66 1st
2.07 2.07 1.78 2nd
1.35 1.43 1.30 3rd
1.00 1.00 1.00 4th
0.80 0.80 0.74 5th
0.62 0.62 0.50 6th

93's -- M28 had a 2.73 rear end ratio, M29 has 3.23 ratio
94+ -- All M6 have 3.42

Basically, the reason for the two trannys in 93 is as follows: When GM began production on the F-Body in 93, borg Warner didn't have the F-Body spec T56 ready, so GM went to Chrysler/Dodge, and bought XXXX amount of Viper T-56's. The M29 is rated at 400 lb/ft while the M28 is rated at 350 lb/ft.

The close ratio of the M29 and the 3.23 rear is actually a little more stout than the 94+ ratio with the 3.42.

And BTW, check the link in my sig. The Purple Pearl T/A I just bought for $6000. The mods are in the link also. If that's not a deal, I don't know what is.

 

Depends on how much cash you're offering...

 

isnt the 94+ trannies capable of handling 450lb/ft tq?

 

Yes.

 

It is in the for sale section, do a search on titles containing "wholesale". If you are interested, i can send you pics and give you more details. I am asking $18000 (thus the "wholesale" price) and I can deliver the car.

Thanks for all of the help, I am learning a lot.

Dustin
dkeers@iupui.edu