PDA

View Full Version : 93s and 24X Guide



Neil350
04-05-2013, 02:32 PM
A lot of the 93 guys seem to have questions which is understandable, owning a 93 for so long you begin learn they are just different enough to become annoying quickly. One thing to keep in mind, once you remove the engine harness and ECM, your 93 really isn’t much different than a 94 LT1 sans a few sensors, the intake manifold and location of the oil pressure switch.

Timing Cover: No OBDI LT1 timing cover will work, so that’s the same as any 94 or 95. If you’re retaining a stock style timing chain, you can use a 96-97 LT1 cover. There seems to be come misconceptions on the billet cover, that’s for double roller timing sets not necessarily a 93 thing.

Throttle Body: If you look at a 93 IAC versus a 94, the IAC in the 93s screw in to the bottom IAC plate, the later cars bolt in. Whoever builds your harness needs to know what syle IAC you plan to use. If you have any after market TB and want to convert to the newer style, you will need the newer style IAC housing. On the AS&M units, these units can be interchanged. If you’re looking at ordering a new Throttle Body and your car is a six speed, you can use any 94+ TB you want. 93 autos, if you plan to keep the factory 93 4L60, it will still need the provision for the kick down cable to attach to the throttle body. So keep that in mind when ordering or buying a throttle body.

ATI Dampner: You're going to need a new crank hub, the OBD1 cars didn't have a crank reluctor, so the hubs are essentially longer. When you order an ATI it's the same part for 93-97 F-bodies. What you will find is a spacer, this spacer is used for a OBD1 LT1 to space the hub out so you have proper belt alignment. When you do the 24X you do not use the spacer as it will not be needed. I run this with a GM bolt, works fine and the belt aligns with no issue. Not sure if that's an ATI thing only, Power Bond and a few others also make nice pieces for the LT1s.


Oil Pressure sending switch: All 93s have this by the oil drain plug and level switch on the driver side of the motor. I have heard early 94s may as well, you need to let who ever builds the harness know that so they extend the harness to reach your factory switch. I left mine in the stock location and it reads fine.


Intake Manifold: I am still using the 93 intake manifold and rails. My fuel pressure regulator is an aeromotive for a 94+ that was modified by Force Fed Fabrications to work on the 93 rails when they did the fuel line set up. But your intake will be fine.


Heated O2s: You will need heated O2s, I ordered some from a 94, they work fine.


Knock Sensor: the 96-97 Knock sensor will work in place of your original, that’s what I have on mine.


Gauge Cluster: All LT1 gauges will work with the exception of the tachometer which will need some programming changes in the PCM, that goes for all LT1 clusters. I am using a 93 gauge cluster in mine still, everything reads fine. My service engine light how ever does not work.


OBDII Communication Port: On the 93s, I believe the keyless entry is programmed using the OBDI port under the driver knee bolster (The thing you've been sticking paper clips in to flash codes), from what I can tell you would loose this functionality. I still have OBDI port taped off and tucked away.

Harness: The Harness I had built by EFI Connection routed and plugged in fine, under the passenger side of the dash it plugged in to the necessary connectors with no issues. No different than any other LT1 far as I know.


ABS/VATS: The ABS in my 93 functions with the 24X, VATS is disabled in the LS1 PCM. ShoeBox has a write up on to disable the VATS relay if you're concerned. Mine worked fine with out the relay disabled.


M29/M28/700R4: I am not using a 93 trans so I can’t comment on that. Some other folks here have how ever and I am sure they can comment.

Intake for MAF: If you ordered a cold air specific for a 93, it's going to be longer where it meets the elbow, you'll have to trim it back to fit a MAF sensor.


Other Notes: Other than those things, it’s no different than a 94+ car.
The A/C Still works, my cruise is gone so I can't comment on that.

Puck
04-05-2013, 04:30 PM
Some good info in here, should be a Sticky :)

Madman337
04-05-2013, 11:00 PM
Some good info in here, should be a Sticky :)

AGREE 100% and subscribed, thanks Neil we need more 93 love because the info like chip programming ect doesnt seem to allpy to us ect ect and that annoying as hell to me so far.

383z
04-06-2013, 06:42 PM
Throttle Body: If you look at a 93 IAC versus a 94, the IAC in the 93s screw in to the bottom IAC plate, the later cars bolt in. Whoever builds your harness needs to know what syle IAC you plan to use. If you have any after market TB and want to convert to the newer style, you will need the newer style IAC housing. On the AS&M units, these units can be interchanged. If you’re looking at ordering a new Throttle Body and your car is a six speed, you can use any 94+ TB you want. 93 autos, if you plan to keep the factory 93 4L60, it will still need the provision for the kick down cable to attach to the throttle body. So keep that in mind when ordering or buying a throttle body.

Question: So I need to switch from a 93 IAC to a 94 IAC in my AS&M 58mm TB or I can just inform BP Automotive I will use a 93 IAC?

ATI Dampner: You're going to need a new crank hub, the OBD1 cars didn't have a crank reluctor, so the hubs are essentially longer. When you order an ATI it's the same part for 93-97 F-bodies. What you will find is a spacer, this spacer is used for a OBD1 LT1 to space the hub out so you have proper belt alignment. When you do the 24X you do not use the spacer as it will not be needed. I run this with a GM bolt, works fine and the belt aligns with no issue. Not sure if that's an ATI thing only, Power Bond and a few others also make nice pieces for the LT1s.

Question; I HAVE TO buy a ATI Dampner or can I use a 94-95 crank hub? Is this if I'm using a ATI Dampner? Which I'm not.

Heated O2s: You will need heated O2s, I ordered some from a 94, they work fine.

Question: Will Fastbird's heated O2 convertion harness be the easiest way to go and just order gm 94 heated o2 sensors?

Gauge Cluster: All LT1 gauges will work with the exception of the tachometer which will need some programming changes in the PCM, that goes for all LT1 clusters. I am using a 93 gauge cluster in mine still, everything reads fine. My service engine light how ever does not work.

Question: Do you know why the service engine light does not work and will I be able to make it work.

OBDII Communication Port: On the 93s, I believe the keyless entry is programmed using the OBDI port under the driver knee bolster (The thing you've been sticking paper clips in to flash codes), from what I can tell you would loose this functionality. I still have OBDI port taped off and tucked away.

Question: How will this effect me? Basically I a mechanic wont be able to use a scanner to diagnose a problem?

Harness: The Harness I had built by EFI Connection routed and plugged in fine, under the passenger side of the dash it plugged in to the necessary connectors with no issues. No different than any other LT1 far as I know.

Question: How many hours did it take you to put in the harnes from start to finish and can you estimate how many hours it took to do everything?

Question: Do I need to have a MAF sensor and can I just get it tuned with out one, speed density?
I know I'm asking a lot of questions, but I don't want to make any costly mistakes or waste time. I thinking about doing this very soon.

96lt1m6
04-06-2013, 07:24 PM
Neil you are awesome, I told myself I would NEVER own a 93 after being a HUGE 3rd Gen speed density fan back when they were new 90-92:( thought I learned my lesson lol

Sent from my LG-P999 using Tapatalk 2

Fastbird
04-06-2013, 07:44 PM
I can help with a few of these.


Question: So I need to switch from a 93 IAC to a 94 IAC in my AS&M 58mm TB or I can just inform BP Automotive I will use a 93 IAC?

Depends on if Bill has access to the square four pin weatherpack connector (he should, it's a common piece).


Question: Will Fastbird's heated O2 convertion harness be the easiest way to go and just order gm 94 heated o2 sensors?

No need to because the BP harness will have the proper oxygen sensor ends and heater circuits.


Question: How will this effect me? Basically I a mechanic wont be able to use a scanner to diagnose a problem?

Just tell whatever person you have scan it to disregard the fact it's an OBD1 car and to scan it with the OBD2 scanner. Some may get it, some may not and give static. Just explain that you've converted to an OBDII computer and it reads codes fine.


Question: Do I need to have a MAF sensor and can I just get it tuned with out one, speed density?

Need? No. But unless you're Forced Induction maxing out the MAF, it'll be tuned.......I'm going to say better........with the MAF than in speed density. Reason I say that is because to really dial in a speed density tune you've got to spend a shit ton of time driving, logging, changing, repeat, to infinity. It'll be a lot closer a lot faster with the maf.

Going to sticky this now.

Puck
04-06-2013, 08:51 PM
AS&M sent me the wrong IAC plate for my 93, and when I emailed them they gave me the option to either send the plate back to exchange for the correct one, or to ship me the newer style connector free of charge. I went with the newer style IAC pigtail, and spliced it into my harness to run the newer bolt on IAC on my 93. I was changing the IAC anyway since my screw in one was sticking so didn't mind having to buy the 94+ style.

Moral of the story is that the physical IAC circuit is the same, so you can keep your 93 IAC if you don't want to buy a new one and just splice in the older square connector into the harness. Colors match and everything, but you will have to follow the wires up into the loom to tell them apart. Mine all looked the same nasty green since they were old, but following them up into the loom they slowly turned the proper color so I could splice them in.

Neil350
04-07-2013, 12:08 AM
Question; I HAVE TO buy a ATI Dampner or can I use a 94-95 crank hub? Is this if I'm using a ATI Dampner? Which I'm not.



No, an ATI is not needed, you could reuse a stock set up or go with any number of after market if you so choose to do. The key is making sure the crank hub is the correct length to accommodate for the reulctor wheel. You need a 96-97 hub for an F-body, 96-97 LT1s were OBDII, they had a 4X reluctor wheel from the factory, the tooth count isn't what matters since the custom 24X reluctor wheel is machined to be the same thickness. From Nook & Tranny (http://www.nookandtranny.com/Info_LT1.html), here are the differences in length. As you can see below, the right hub is important to maintain belt alignment.

Crankshaft Hub, 92-95 LT1 Corvette, 93-95 LT1 Camaro/Firebird, 3.516" Length, GM

Crankshaft Hub, 96 LT1 Corvette, 96-97 LT1 Camaro/Firebird, 3.416" Length, GMCrankshaft Hub, 94-95 Impala/Roadmaster/Caprice 4.09"

Crankshaft Hub, 96 Impala/Roadmaster/Caprice 3.99"

Neil350
04-07-2013, 12:16 AM
Neil you are awesome, I told myself I would NEVER own a 93 after being a HUGE 3rd Gen speed density fan back when they were new 90-92:( thought I learned my lesson lol

Sent from my LG-P999 using Tapatalk 2

Those were the best running ones though, didn't a lot of guys convert the 85-89 MAF cars to the speed density set ups? I still want a nice Formula 350.

96lt1m6
04-07-2013, 09:27 PM
Correct... the 90-92 did have issues with the tachometer while having large camshafts.. tachometer would bounce and become erratic at times:( we were still running 11s all over H town:)

Sent from my LG-P999 using Tapatalk 2

highlander
09-05-2014, 09:31 PM
https://www.youtube.com/watch?v=sMG_PHdnQeM

Neil350
09-07-2014, 10:18 PM
Killer High Lander, I see you did the 58X with Drive By wire.

Toph
03-12-2015, 08:44 AM
So on a '93 is it worth picking up a MAF, or am I better off without it and tuning it out? If it's best to add a MAF, are there any I should stay away from?

gmpowered
03-12-2015, 02:54 PM
I would add a maf, You need to understand the LS pcm and the pro's and cons of running Speed density, open loop ect that im not going to get into.

I would run an LS maf it would be easiest to set up, You could also run an LT maf, any tuner can do either. The LS has MAF tables more readily available in efilive hpt formats. Depending on the pcm you use the motor would probobly fire and run better untued with a maf matched to the pcm. Mine fired with an LT1 maf and ran lol.

Stay away from aftermarket MAFs, pick up a used GM unit.

Toph
03-12-2015, 04:27 PM
Ok, that's kind of what I figured. Thanks!

Homerandabe69
05-19-2015, 08:22 PM
Finally got my 93 24x setup running. Still have a lot of work to do but got an ok idle after I adjusted the fuel pressure.

Second start attempt with shitty idle (https://drive.google.com/open?id=0B_RMOchAEUwdcDMweDA0Z2trV0k&authuser=0)

I also have the IAT sensor disconnected as well as the accessories because I am still waiting on parts to arrive.

Neil350
05-27-2015, 10:31 PM
Nice man, it takes a while to get these things lined out. That things that fund this hobby, i.e work are what tends to get in the way of time.