Need advice for Auto to Manual conversion.

[taztaz]

Hello all,

I have owned my NSX for a long time now. Have always wanted to do this conversion. I know and have read some threads about this swap in this forum. I have decided to do the swap because where I live there weren't any manual NSXs imported and even if there were, most of them are kept as collectibles (maybe about 4 units).

My question is to ask what other parts would I need apart from the ones I have listed below. Please shed some light as to any complications to look out for towards this swap.

6 Speed Tranny
NSX-R input shaft
4.23 Ring & pinion
Clutch Master Cylinder
Clutch Slave Cylinder
Clutch lines
Clutch and flywheel kit
clutch alignment tool
Clutch paddle, Brake paddle assembly
Shift knob and bootie

LSD ??

I also realize that the Cams will have a different profile, but I am wondering if the ECU and harness needs to be changed as well.

Thanks for the help and support guys and gals.

Taz

 

[Honcho]

A couple things:

1. You will need a manual ECU and I would recommend swapping in some manual cams. If you are spending the $ to go this far, you should do it all the way. I am sure someone on Prime can find you a set of used cams for much less than Honda new.
2. You will need a method for activating the reverse lockout mechanism, which the 6-speed uses to prevent 5th to reverse shifts. SOS sells a control box similar to the OEM logic, or you can wire the solenoid to the brake light switch.
3. If you want to use the NSX-R 4.23 ring gear, you need a 91-94 LSD. I would recommend increasing the pre-load on the LSD by using the NSX-R spring plate if you go this route.
4. In addition to the shift knob and bootie, you will need the complete shift linkage assembly, which comprises the lever mechanism in the console and the two linkage cables that go back to the transmission. Also readily available from scrap yards.

HTH

 

[4AU4LIFE]

couple of other things come to mind as well.
1. The tach is different but not sure about the other gauges
2. The center console should be different also.

 

[shawn110975]

yeah your old instrument cluster has the auto and gear selection in the cluster,

the wire harness from the ECU to the engine,

the harness from the cluster to the ECU

then the wire harness from the front fuse box under the driver bolster to the engine,

the heads the intake manifold, new valves/springs as I think they are different but maybe wrong on that one.

no-one has really ever flat out said HOW honda DE-Tuned the engines to have less HP so I dont know.

and if you used a 5-speed tranny instead of the 6speed you would not need to buy the new input shaft.

also need flywheel, the list goes on and on. sell the auto

save up and have a manual shipped in

where are you at ? there are prime members all over the world some prob live down the street from you.

or you could convert to a rear wheel steering from a 4WS prelude and really burn thru some money

 

[taztaz]

Firstly, I am glad and happy to see the replies by all of you. Great to see the help coming in.

Long story short. We have purchased our NSX (92-93 model) about 10 years ago. We purchased it from an auction. The car has been well kept prior to the auction and only had about 500 KM done on it. Since then we have put about another 25,000 KM to it. We seldom drive it as well as it is garaged most of the time.

When we purchased this NSX we also realize a Tag on the Engine that says "Engine prepared by Terry Hoyle" (As googled, http://www.racecar.co.uk/terryhoyle/about.html).

I am trying to contact them as to what was done to this particular NSX. As what I can see, a full DC sports header to full exhaust system was done. I don't know if any internal engine parts were changed or modified.

Where I live (Brunei) we cannot import any used vehicles that exceeds 2 or 3 years old. Hence my difficulty in just selling this very low milage and good condition NSX and purchasing a Manual NSX.

I will continue to research on this and will try to start on this project as soon as I have gathered enough information to be more confident in doing the conversion.

Once again, thanks for the feedbacks and hopefully more information will be posted doing this and will be of great info for future owners who are interested in this conversion.

Cheers
Taz

 

[Honcho]

the heads the intake manifold, new valves/springs as I think they are different but maybe wrong on that one.

no-one has really ever flat out said HOW honda DE-Tuned the engines to have less HP so I dont know.

hey Shawn-

Intake, heads and valves are the same manual or auto. The "de-tuning" is easy- Honda used cams with lower lift in the autos. You have to swap in manual cams. Also, I believe the auto ECU limits revs to 7500 rpm.

 

[nsxinkl]

I have done this conversion. It is not necessary to change the cams, the cluster gauge or the ecu.

Contact me if you need any help. I am close by in kuala lumpur, Malaysia. I have some parts which you need too. Eg very good condition clutch and LSD.

 

[taztaz]

Hi NSXINKL,

Thanks in advance. I will soon pm you and glad to hear someone near by who has done this conversion.

Am wondering if you managed to convert it to a 6spd or a 5spd ??

Cheers
Taz

 

[nsxinkl]

Hi NSXINKL,

Thanks in advance. I will soon pm you and glad to hear someone near by who has done this conversion.

Am wondering if you managed to convert it to a 6spd or a 5spd ??

Cheers
Taz

I have a 5 speed jdm mt with nsx-r final drive and input shaft and ATS carbon LSD. I chose 5 speed because I have been told it is can withstand more abuse from higher hp. My nsx has close to 500 rwhp.

 

[4AU4LIFE]

I have done this conversion. It is not necessary to change the cams, the cluster gauge or the ecu.

Doesn't it look a bit odd have a tach with the gear selection list on it? Does the tach also reflect the lower RPM max for the auto tranny?

 

[nsxinkl]

Doesn't it look a bit odd have a tach with the gear selection list on it? Does the tach also reflect the lower RPM max for the auto tranny?

I had the auto tachometer until recently. I agree it does not look nice but it is not required for the auto to manual conversion. Luckily for me a fellow nsxprimer gave me the manual tachometer recently.

 

[taztaz]

I have a 5 speed jdm mt with nsx-r final drive and input shaft and ATS carbon LSD. I chose 5 speed because I have been told it is can withstand more abuse from higher hp. My nsx has close to 500 rwhp.

Hi,

Since you have done this conversion, is it possible for you to help me out by messaging me what parts I need. Please let me know what left over parts you have that you are willing to part with.

Thanks Thanks !
Taz

 

[yellow-scorpion]

I believe the Lt or Rt axel is also different. you can mod the auto engine harness to work. I had Driving Ambitions do the conversion and they did an excellent job. Can't even tell the car was an auto. Have you started to swap?

 

[garylario]

hi nsxinkl
i have some NSX question about auto to manual conversion
would you mind pls give me your email contact?
thanks
Gary