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4port engine to 6port engine swap?

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Old 08-24-2012, 09:00 AM
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4port engine to 6port engine swap?

I've searched around the forum and couldn't find anything about this.
I have a 5-speed 4port engine with 192hp, but it broke down, there was sand in the engine!!! The previous owner installed a shortram filter from china, 5000km ago i swapped to aem cai, but it was to late.
I found a 250hp 6port on the internet (it's from japan, but is now located in Finland) what do i need to make this fit to my rx-8?

Here are some pictures on the new engine (including manifold)
MAZDA RX-8 2004 - RX-8 RX8 13B - Auton varaosat - Nettivaraosa

I also need a new clutch, but should i then buy the 6-port clutch, if i do the engine swap?

If this is possible?
Old 08-24-2012, 09:02 AM
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Will this 6-port fit with my ecu and 5speed gearbox?
Old 08-24-2012, 09:04 AM
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The problem is not with the clutch. You need the 6 port intake manifolds (upper and lower), the ECU that can run the 6 port, and the engine bay harness, at a bare minimum.

There is a thread around the forum somewhere where a guy did the 4 port to 6 port swap, and it wasn't quick, pretty, or cheap. It's doable, but it is going to cost you quite a bit more than selling your car and buying a 6 port (Hi power I believe it's called over your way), probably even still true with a dead engine.
Old 08-24-2012, 09:18 AM
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Originally Posted by RIWWP
The problem is not with the clutch. You need the 6 port intake manifolds (upper and lower), the ECU that can run the 6 port, and the engine bay harness, at a bare minimum.

There is a thread around the forum somewhere where a guy did the 4 port to 6 port swap, and it wasn't quick, pretty, or cheap. It's doable, but it is going to cost you quite a bit more than selling your car and buying a 6 port (Hi power I believe it's called over your way), probably even still true with a dead engine.
The engine is complete (look at the picture on the link) there is the intake manifolds?
Old 08-24-2012, 09:28 AM
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Yes, they are on there. Still got a bunch of work to do.

Full conversion thread: https://www.rx8club.com/specific-per...4/#post2563386
Some of this wouldn't apply since you are already MT, but there is still quite a bit needed.

This is not your average conversion thread asking how much it would cost or how to do it, so please keep flames and bullshit out of my thread.

This is the first thread and I am probably the first person (that I am aware of) to post that they have DONE IT.

This is intended for future use of other enthusiasts who may wish to do the swap. I'm not going to give a step by step, but rather a general idea of what is necessary and how to go about it. I will give a few hints and tricks I learned along the way to save money and time for others.

My car was an early build 04 AT with 117,800 on the original engine and a reman trans. I bought it for dirty cheap with the intention to convert it and mod it at some point. I drove it for over a year as an AT to learn how the car responds and drives, while gathering parts and information for the swap.

I bought almost all the necessary parts for the swap from one single partscar to simplify matters. I had to source a few parts via ebay, other parts sources, and new from mazda when they were not available used. Here is the list:

-complete 6 port engine with all external parts, manifolds, injectors, flywheel, and wiring harness (including the wiring that goes from the battery terminal, to fusebox, to starter). Of course I rebuilt the engine before use since I can do so for just a few hundred dollars in parts cost and a few hours of labor.

-6sp trans, I chose to have mine gone through before install to replace the questionable/troublesome 2nd gear synchro

-MT starter (if possible the upgraded/high torque starter is greatly preferred)

-clutch parts (I used stock stuff but you could always buy a new clutch kit instead)

-6sp carbon driveshaft if available, however YOU CAN USE THE AUTO DRIVESHAFT WHICH IS STEEL BUT DIMENSIONALLY IDENTICAL. IT should not have a major impact on driveability or acceleration, if any at all, but it is heavier than the carbon MT shaft.

-clutch slave cylinder, master cylinder, hard line and soft line (I bought a SS braided line for a little over $20 instead of using the stock rubber line)

-shifter assembly, ****, boot, inner trim ring (goes inside the silver trim ring on your console, which will get reused from your automatic)

-clutch and brake pedal assemblies (be sure the clutch pedal comes with the rod that actuates the master cylinder, some people remove them). The pedals I found had the pretty aluminum pads, so I also bought the matching accelerator pedal and dead pedal that also did, but this is completely optional/cosmetic and doesnt have anything to do with the swap itself. From what I could tell the accelerator pedal was identical. Also hope that they leave the switches on the clutch pedal for the starter interlock and cruise switch.

-dual oil cooler assemblies with plumbing. You need both coolers, with mounting brackets, and mounting hardware. Be sure to get the ducts that go between the coolers and bumper. There is a long hard line that goes between the coolers, and the shorter hose between the front of the engine and the passenger cooler is also different and must be obtained. The driver side cooler, and it's plumbing, are technically identical to your stock AT's driver-side-only cooler.

-MT steering wheel (to get rid of the paddles which will be useless)

-MT gauge cluster (for the higher rpm tach, to eliminate the AT warning light, gear indicator, etc.)

-MT PCM. Here is where it gets tricky, read more below about this.

-MT ABS pump from the same car the PCM came from.

---------------------------------------------------------------------------------------------------

Here are some hints and tricks I learned along the way.

PCM/KEY/CAR COMPATIBILITY:

I got the PCM from the MT car but then it wouldn't work with the keys in my AT car, because of the transponder chip in the key. The PCM is programmed to look for a specific key chip, and so the MT PCM was still looking for the keys from the car it came out of. As a result, I was initially unable to start and run the engine using this PCM.

I was able to plug my AT PCM into the MT engine harness and fire it right up using my stock keys. One plug from the MT harness will not fit into the AT PCM, this plug operates the auxiliary ports etc. and are not necessary to start and drive the car so it can be left unplugged temporarily.

The AT and MT cars use different injectors, and as a result I would not take the MT engine (with MT injectors) above about 4000rpm due to the fuel flow differences, or risk engine damage as a result. I was breaking in a fresh engine so this was fine by me regardless.

I went to one dealer tech and he said he could not make the MT PCM work in my car, and was afraid to touch it. HE recommended that I try to obtain the original key(s) and ignition cylinder that matches the MT PCM I got, from the same car. HE said if I did this, I could install it on my car and the PCM would be happy and start up.

I was able to find a dealer tech "with a brain" as some others told me I would need to find at a different dealership. He was able to set up the MT PCM to work in my car, with my existing keys and such. Everything in the car then worked except for TCS and ABS. Even my cruise works, and in fact I don't have a clutch pedal switch for the cruise control installed.

Apparently the MT PCM would not communicate with my AT's original ABS unit, so I tracked down the ABS unit that came from the same car as the MT PCM, hooked it up and it regained ABS/TCS functionality. There is probably a way around this, perhaps my dealer tech didn't know how to program the original ABS unit in my car to communicate with the new PCM for some reason. For me this was the easiest method, but I am sure there are other ways to resolve this issue.

WIRING/CLUTCH PEDAL SWITCHES:

I am still using the AT dash wiring harness and engine-bay wiring harness. The only differences in the dash wiring SHOULD be related to the clutch pedal switches. I found this easy enough to get around...the cruise already works, so no need for wiring up the cruise clutch switch.

For the starter circuit I ran a wire from the ignition switch, to the clutch interlock switch, to the starter trigger terminal. On the end of the ignition switch, find the white wire with blue stripe (at least it was on my car), in a group of about 6 or 7. Probe this terminal with a DMM (grounded elsewhere) to be sure there is 0vdc+ when the key is off, or in the ON position, and then 12vdc+ when the key is turned to START.

Once you have verified this wire is the start trigger, splice onto it and run your new wire down to the clutch interlock switch on the clutch pedal bracket. This will be the switch on the back of the pedal near the firewall. Polarity does not matter, just that one wire goes in and one more comes out. I used a spare fuel injector plug/pigtail since my AT dash harness lacked this connector, one from an older nippondenso square style fuel injector, it went right into place like it was made for it. My ignition start wire goes to one wire on this plug, and the other wire on the plug then gets run through the firewall down to the starter.

ON the starter find the small trigger terminal on the solenoid, the only male blade terminal. Do not use the factory plug for this, run your new wire to it instead. Now your starter circuit is complete, and requires the clutch pedal to be depressed for the engine to start, just like stock. IF you get a no-crank, use your fingers to fully depress the clutch switch manually, and check using the key turned to start.

IF it operates then, that means your clutch pedal is not fully pushing the switch, and you must either adjust or shim the arm on the switch. I had to do this to mine. I checked the extra distance needed to fully depress the switch, which was about the width of my fingertip. I removed the little green plastic stopper from the clutch pedal that pushes against the switch, and taped on a spare nut (from a bolt) onto it, in order to push the switch further, then it worked perfectly.

OTHER MISC INFORMATION:

The steering wheel is a direct bolt on/plug in, you reuse your original airbag. I didn't even need a puller for my wheel, I just removed the big nut and pushed hard side to side on the wheel and it released from the splineshaft/column. BE sure to have your old wheel centered before removing it, so you can re-center your new wheel and not have it sideways while driving down the highway.

The powerplant frame is identical between auto and manual. No need to change.

The exhaust is identical between auto and manual.

The hole and mounting points for the shifter assemblies are identical.

I did not install the VFAD on my car, I simply capped the vacuum nipple on the intake manifold that operates it.

Again, you could technically use the automatic driveshaft (steel, fat, heavier) with the MT conversion, but I used the manual driveshaft (carbon/plastic, skinny, lighter) since I had it. They are dimensionally identical as far as the mounting points and length, including the front yoke/splines.

The hole is already cut in the firewall for the clutch master cylinder, there is a plastic filler plate there that simply pops out. The master cylinder can then slide into place, and the clutch pedal slides onto the MC studs inside the car, and then you use 2 nuts to bolt it together on the firewall. I did have to unplug and remove the trans control module (TCM) for the AT, which is bolted in place of the clutch pedal.

The clutch master gets it's fluid supply from the brake MC, and there is a hose that goes from the clutch MC to the brake MC reservoir. The res. has a casting for the nipple, but it is not present. I took my res. off of my BMC (it disconnects via a locking pin underneath the res.) and drilled a hole into it, then inserted a brass fitting that I could connect the clutch MC hose to. This needs to be done with care, you do not want to develop a leak here which could cost you your brakes and clutch while driving. Alternately you could probably order the MT version of the brake MC reservoir with the nipple already cast in.

The firewall of my AT already had the clips that hold the clutch hard line so it went into place like factory. The mounting studs for the bracket that holds the hard line and soft line to the firewall, near the oil filter, are also present on my car so it was also a bolt up affair like stock. THen it is simply a matter of bleeding and adjusting the clutch pedal via the rod and locknut inside under the dash.

The rearend gearing and LSD appear to be identical, as are the halfshafts.

GAUGE CLUSTER CONCERNS:

The MT gauge cluster plugs directly into the stock AT dash wiring and everything seems to work normally. IT did take a few minutes for my gas gauge to come up to the proper level, it seems to have a buffer that slows it's movement a lot. I did have the presence of mind not to install this before going into the dealer for the PCM programming...because the mileage information on the odometer is stored IN THE CLUSTER. As a result, the MT cluster shows lower mileage than my AT car has on it. Dealers always document mileage during any service, so if I had plugged in the MT cluster before taking it in for service, CARFAX would have picked up a mileage rollback discrepancy which would follow the car for life. To avoid this, I waited until the dealer was done to install it.

I did inquire about programming the mileage of my car into the MT gauge cluster, and was told it would probably not be possible to do. Apparently when a cluster must be replaced, a new one is ordered, and the cluster manufacturer (apparently subcontracted by mazda) asks the mileage that the dealer wants put into it before shipping it out. They will apparently not service used units due to possible legal issues.

BRAKE PEDAL SWITCH:

The automatic uses a long cable that runs from the ignition switch, to the brake pedal switch, to the shifter. I had to remove this cable so I could swap pedals, and so that the ignition cylinder would be unlocked without the auto shifter going back into park. For the time being, I removed the cable from the brake pedal switch/housing, since I was not sure how the switch came off of the pedal bracket because I couldn't see it very well.

Once I got the pedal out and compared it to the MT brake pedal, I discovered that this switch would not install onto my MT pedal. Then after studying it for a while longer, I learned that the AT switch actually comes apart in 2 halves, and the upper half (the electrical part) WILL install onto the MT pedal. So then it was all good, I installed the switch with a simple twist, and it plugged right back into my dash harness like stock. I imagine that the MT car uses the same switch, just without the lower half/housing that the AT adds on. The purpose of this lower housing is to accomodate the cable that runs from the ignition to the shifter, though I admit to having no clue why it needs to run through the brake switch.

Once the switch was plugged in, I did have to adjust pedal height to get it to work properly. This switch controls when your brake lights come on as you touch the pedal, and my lights were stuck ON all the time.

---------------------------------------------------------------------------------------------

That is all I can think of right now. Hopefully this puts to rest some of the bullshit spewed on this forum routinely about AT to MT conversions.

Last edited by RIWWP; 08-24-2012 at 09:31 AM.
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Old 08-24-2012, 09:47 AM
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Hmm... Almost everthing is about manual/automatic change.

What needs to be done on just the 4port to 6port to make it run, i dont need a new dashboard or something like that.

Does a 4port 210hp from japan fit on my car from eu?
Old 08-24-2012, 09:53 AM
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Yes, a 210hp 4 port engine should work. It's not the power output, it's the 4 port vs 6 port difference. The intake valving, runners, and fuel injection are different, and it requires the ECU and wiring harness to control that properly. Once you replace those, then there is a bunch of other stuff that has to get replaced that the ECU is expecting, even if the engine technically doesn't need the difference. Like the immobilizer related stuff, the keys that are paired to that ecu and immobilizer, gauge cluster for the info (like tach, etc), the ABS pump (paired with the ECU), etc...
Old 08-24-2012, 10:42 AM
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or you use a piggy back ECU such as the Adaptronic to manage all the 6 port stuff... this is my plan when I dump my 4 port (once it dies -- hopefully some day far ahead in the future) and replace it with a newer 6 port motor....
Old 08-27-2012, 09:24 AM
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Originally Posted by RIWWP
Yes, a 210hp 4 port engine should work. It's not the power output, it's the 4 port vs 6 port difference. The intake valving, runners, and fuel injection are different, and it requires the ECU and wiring harness to control that properly. Once you replace those, then there is a bunch of other stuff that has to get replaced that the ECU is expecting, even if the engine technically doesn't need the difference. Like the immobilizer related stuff, the keys that are paired to that ecu and immobilizer, gauge cluster for the info (like tach, etc), the ABS pump (paired with the ECU), etc...
What do i need to do to make the automatic 4port to fit? I've heard that it's hard work to change the flywheel.
Old 08-27-2012, 11:04 PM
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I'm not familiar enough with the differences between AT 4 port and MT 4port to be able to answer that. In theory, it is just the flywheel, clutch, and bellhousing, but it's just theory to me. The 4 port MT was never in the states, and it's relatively rare that someone with one posts here.

Might want to find an engine builder located in Europe and call them up to discuss.
Old 07-25-2013, 09:18 PM
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i had access with JDM 5 MT, lemme bring this dead thread up

for future reference, the 5MT is mostly the same as the 6 MT part BUT! because 5 MT is base grade in Japan, so their wiring is different Than 4 at and of course 6 MT. so doing a 5 MT swap is pretty much the same as doing a 4 at to 6 at/6mt swap. you need almost everything including ECU and such. and mind you all, 5 MT does not have DSC and stuff. and the wiring does not fit USDM car (RHD/Lhd differences)
Old 07-25-2013, 09:31 PM
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Originally Posted by nycgps
i had access with JDM 5 MT, lemme bring this dead thread up

for future reference, the 5MT is mostly the same as the 6 MT part BUT! because 5 MT is base grade in Japan, so their wiring is different Than 4 at and of course 6 MT. so doing a 5 MT swap is pretty much the same as doing a 4 at to 6 at/6mt swap. you need almost everything including ECU and such. and mind you all, 5 MT does not have DSC and stuff. and the wiring does not fit USDM car (RHD/Lhd differences)
Say what ?????

I did a 6MT to 5MT swap . Straight swap - no issues ...................
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