I just want to make sure I have things correct. To make an 01-02 pcm work in my 1998 Z28 I need to re-pin the harness, and get a temp sending unit from an 01-02 car? That's about all the information I could find in the search. The main reason I'm doin this is so when I spray nitrous I can program the PCM to pull timing. Thanks!

 

Why go thru all of the hazzle- get a timing tuner or similar device + save some money.

The Timing Tuner is a device that is installed on LS1 and derivative engine equipped vehicles for adjusting the spark advance ‘timing’ to extract improved engine performance. The unit installs ‘in-line’ with the crankshaft sensor wiring and alters the signal that is received by the PCM (Powertrain Control Module, ‘engine computer’). By shifting the crankshaft signal ahead or behind in time the spark timing in the engine is changed.

The Timing Tuner is used to adjust the Spark Advance to improve engine response and power. Assuming sufficient octane fuel is used, most production engines will make more power with a few more degrees of spark advance. However when Nitrous Oxide or superchargers/turbochargers are used to raise horsepower the spark advance must be reduced (retarded) to prevent detonation. Detonation (pinging, spark knocking) is very destructive and is to be avoided. Always run high enough octane fuel for the power levels desired.

The Timing Tuner also has a Nitrous Oxide (N2O) control feature. The unit features activation delay, timing retard, and activation controls based on RPM. The setup can be optimized for non-N2O driving and when the trigger wire is energized the secondary settings are activated. This ensures the optimum setting is always available both with and without N2O.

Adjustments and LED’s:

The Timing Tuner has several adjustments:
Spark Base: Adjusts the spark advance/retard at all RPMs
Spark WOT: Adjusts the spark advance at RPMs over 3000
RPM: Adjust the minimum RPM to activate the N2O relay
RTD: Adjusts additional spark retard when N2O is activated
MODE: A series of switches to set the N2O activation delay and maximum RPM

The Timing Tuner has 2 indicator LED’s: Both LED’s turn on for a moment when the unit is powered up, this is for checking LED operation. The Green LED will blink once when the settings are changed to indicate that the change has be recognized.

Green: Indicates that the unit has synchronized with the crankshaft and is controlling spark advance timing.

Red: indicates that the N2O relay has been turned on and the RTD spark advance setting is active.

The LED’s also are used to indicate various detected error conditions within the Timing Tuner System.

Green: 1 blink – Crank sensor pulses detected out of order.
2 blinks – Noisy crank sensor signal (reroute wiring)

Red+Green alternating: Incorect connection or operation is detected with the N2O pilot relay. The relay must be connected as shown in the Connection Diagram.

Turning the engine off resets all detected error conditions.

N2O trigger and Delay
The Timing Tuner has several features for control of N2O:
• Activation Delay
• Minimum RPM
• Maximum RPM
Activation Delay is used to delay the activation of the N2O system so the car’s suspension has a chance to react and plant the rear tires before the N2O ‘hits’. The delay is adjusted by setting Mode switches 1-3, see the table below. The delay happens once in a race, if the N2O is deactivated during a race and the engine RPMs do not drop below 3000, the delay is bypassed when the N2O is retriggered. This is useful when bracket racing and trying to stay ahead of the competition without ‘breaking out’. Or when traction is lost and the driver ‘lifts’ to stop the wheelspin.

Minimum RPM is a setting for tuning the turn-on RPM for the N2O. This setting is checked after the Activation Delay has expired. It is used in place of, or in conjunction with Activation Delay to control the point at which the N2O is triggered in relation to torque converter stall speed.

Maximum RPM is selected with the Mode 4 switch. It is used to de-activate the N2O system below the PCM rev limiter setting. If the engine hits the PCM rev limiter with the N2O activated, a backfire could occur. It can also greatly extend transmission life on A4 equipped cars by disabling N2O on the shifts.
Mike Licht
www.ramchargers.com

 

Why not just get a custom tuned handheld tuner for your 98 car, and just flash the tune you want when spraying the n20?

30 seconds for a reflash doesn't take too long.

Ryan

 

Almost every pin needs to be changed that’s like 160 pins if Im correct

 

I alredy have a 2001 pcm for an m6 brandnew never used or installed. I might have to look at a timing retarder or something like that.

 

1) PCM wire swap; 4 wires are the same, 4 not used positions are the same
152 /160 need to be swapped.

2) Fuel sending unit is different- might as well upgrade w/ plastic tank + pump upgrade kit like racetronix. Or just not know how much gas you have.

3) Instrument Cluster- 35 pins + add a wire/pin from the serial data port. 98 cluster uses analog inputs from sensors. 99+ use serial data from pcm. Plus, you have to consider the odometer, recalibration is around 200 or buy the special jig for around 6k. Or get lucky and find one with some milage close to yours.

4) Newer pcm / OS -Tuning to boot.

This is not for everyone. There are plenty of really bad *** 98's out there running the original OS. The original post I believe was interested in being able to manage fuel with NO2. EFI Live's Custom OS #5 is right up your alley. You do need to be able to run a later OS to begin with...I have done the painful logic truth table in Excel for the wire swap. I have also made up a 98 to 99 adapter cable in order to run my Moates Controller's Real time tuning on 98s. The idea is to reduce tuning time for 98s. If you don't have a real serious thing for your car, and are not technically capable or even have the time but you want to run later software you might as well sell your 98 and find a 99+ As the cost associated with all the custom work is going to be out of most folks price range. However, if you are dedicated to your car and want to see the project thru I can help you out with the logic swap truth table.
I love my 98. It is the only car I ever will/have bought new. I have a special attachment to it, and I like a challenge.

The timing tuner thing will work I suppose.
Not alot of hand held options for 98s. The Hypertech is the only hand held I am aware of for 98s and it is wholly inadequate. I don't believe the other companies wanted to do anything for the 98s.

 

Very cool wiring adapter for the 98 to 99+ PCM, I've thought about doing that about 5 times, but always decided against it (mainly, hard to find the pcm connectors and pins) I am just going to send Craig a 98 pcm here shorly and get a roadrunner made for the 98 pcm.

I see the waytec catalog in the picture, they don't have any of those connectors do they, I have always only seen metripack 150/280 series in them, no micropack stuff.

SCT does make a custom tunable handheld for the 98 cars, that is why I mentioned it. That is what I use on my car with good results. (same control as the other tuning companies, using the stock OS)

Ryan

 

Innovation at it's finest. Great work Doc

 

Thanks Ryan, TA. I'd didn't know SCT stepped up to the plate on that.

 

Doc:
For those of us that have a serious affection for out 98's but want the RTT of the 99+ cars, what would that adapter cost? Would it work with my HPTuners setup? I have a 02 PCM and engine wiring harness as well as my factory 98 PCM and wiring harness.

 

Damn, I almost wish I didn't find this thread and could still think there might be an easy way to get a newer pcm in my car...

 

maby someday someone smart will make a wiring connector for a newer pcm and make tonz of money. Or maby not!

 

LOL. Ignorance can be bliss....

 

Lets hope soo.

 

I am with the guy above not only for rtt but for 2-3 bar options, what if I have a 99+ harness and computer? I hear Speartech makes a adapting harness, but what would be involved for someone to do this themselves?

Also in the 99-02 range can the computers be swaped like say using a 99 computer in a 01 vehicle? If I had a 99 hp tuner and computer left over but a 01 car and didnt want to have to pay to licence the 01 car.

TIA

 

I am willing to do the re pining since I bought a 98 ls1 and harness for a swap, I also bought a 2000 Pcm, Is there any sensors that need to be changed. I am putting this in a different vehicle anyway so gauges and stuff like that will be seperate from the pcm. I just want to know if any sensors will have to be changed?

 

If you already have the 99 harness / 98 car / then you are in for a pleasant suprise...you will have very minimal wire mods to do (no pcm wire swap, just some interconnects). If you want a fully functioning cluster then you will need a newer (99+up) one and the wire swap for it is 17/35 pins behind the dash.

Yes.

 

The only sensor issue I forsee would be with the fuel sending unit that would centered around what indicator you choose.

Ps. I would hope that your are planning on changing out the rod bolts at a minimum on that 98 motor.

 

Correct me if I am wrong but doesnt speartech sell a harness that allows you to plug in a 99+ harness to a 98 car? I would assume this is a end all harness and no rewiring required.

If you could, would you mind pm'ing or posting some of the specific details about what it would take to make a fully funtioning 98 car with 99+ harness. I think for people wanting the feature of a 99+ tuner then buying a new pcm and harness sounds the easiest/cheapest. Thanks

 

John is a really honest and intelligent individual with integrity and experience rivaled by few if any in this community. He can make anything. Though I am not exactly sure if he has a regularly marketed solution for somebody with a 98 car that has a 99+up harnes and pcm, I am sure he could accomadate it...Maybe John can chime in on it.

I hesistate to use terms like "easiest" in the quest for the holy swap. For somebody like myself who has over 17 years in Aviation Electrical and Electronic experience, it's all relative. When I did my project, I did it with the premise that I was going to do it with the motor in the car. If I happened to have had the motor out at the time I would have elected to get a 99+up harness and go that route. On to the heart of your question, with a 98 car, 99+up harness, in order to be fully functional, behind the passenger side kick panel are three interconnects btw the dash and the pcm. The 99+up motor harness only has two connectors going in. You will need to cut/repin a 3 to 2 connector senario. That is take 3 connectors on the interior car side and reroute them to the 99+up cable(there are empty slots on the connectors). Plus add one wire for the serial data line from those connectors on the kick panel to the dash. Any info further than this, PM me for info. This post is just too long already and Florida is up!