Need Help Type S motor install in progress on SH - Honda Prelude Forum

iammancini · 06-08-2011, 09:05 PM

Hello all, this is my first post on this forum. I was hoping i could get some answers here. Ive been searching around the forums and internet and cant come to a definitive answer on a few questions.

I just bought a type s motor (yes type S with atts). My mechanic took the harness off my sh motor and is installing it on the jdm motor.

He will be swapping the crank sensor(in oil pan housing?) and distributor from the sh to the type s and possibly vtec solenoid.

if i use the sh harness should i use the usdm ecu and atts controller or can i use the jdm ecu and atts controller. I would prefer to use the jdm ecu because of the compression ration difference.

I have noticed that the type s and sh ecu share the same code, how is this possible when the type s has higher compression. Does the ecu somehow compensate (through air flow) and adjust timing/fuel delivery.

Does it really matter what ecu i use since they are the same codes. (P5P i believe)

Is this the best option, or should he keep the type s harness and do some if rewiring if possible?

will i have any issues with emissions tests?

is there a difference between the atts units? Can i just use the atts unit which came on the type s motor.

Thanks for the help!

lilredlude · 06-08-2011, 09:50 PM

i used us atta ecu, and jdm and us ecu. i didn't really notice difference with either. don't know if there actually is one or not.

i failed emissions, but i didn't swap over anything. if you're in ny (or another state that reads ecu's) the jdm ecu will fail.

iammancini · 06-08-2011, 10:20 PM

i actually live in ontario so i guess i will have to use usdm ecu.
did you notice any power diff in motor when you swapped or the 20 hp isnt that big a deal.

do you have any check engine lights with any of the configurations you mentioned?
also jdm atts (talking about actual atts unit not atts ecu) or sh atts unit?

Kronn 98SH · 06-08-2011, 11:09 PM

If you ask on PreludePower, there's a member who just did this swap and tried all the different configuration options.

iammancini · 06-09-2011, 05:41 AM

ok i will try registering on that site when i get a chance

SH DRIVER · 06-09-2011, 06:03 AM

The Type S Prelude in addition to having ATTS ,also had an active braking system ,and they both worked together in some coordinated way.For that reason ,a Type S ecu may be needed if you are attending on going all the way with your conversion.This is something I guess you will have to research
using OEM Type S Prelude tech manual.

lilredlude · 06-09-2011, 06:22 AM

actually, i think i just got the motor, so i used my us atts, and my swap didn't come with jdm atts ecu. i can't remember if i had cel or not, its been awhile and i sold that car. the guy that bought my car is also on prelude power, although i can't remember if hes too active. i think he has some posts about his time slips from it too. thestapler is his sn.

iammancini · 06-09-2011, 04:30 PM

so its all just a big mystery lol.
well that sucks

minilogoguy18 · 06-09-2011, 05:23 PM

I'd say use the ECU that goes with the car but like said it probably wont pass emissions, that's why we don't get any type R's. The comment about the active braking is more than likely false, ECU only controls the engine, the Type S active braking system was a newer type of ABS which has it's own control module.

iammancini · 06-10-2011, 05:02 AM

im not concerned with the active braking system since im not isntall that option.
right now its a matter of determining what atts unit to use, sh or type s. as for the ecu they should be simple enough to swap back and forth

lilredlude · 06-10-2011, 07:58 AM

both should start it up and run it. see if you notice a difference.

minilogoguy18 · 06-10-2011, 07:59 AM

Never heard of the ATTS unit being different in the Type S but it's a motor most people don't buy. If you have the ATTS unit and control unit from the Type S then use both together.

This swap from what I can tell should be pretty straight forward, use your old wiring harness, fuel rail and use both computers that came with it and you'll be fine. That engine doesn't have any extra stuff on it, just different internals, the ECU that came with it would definitely bring the most out of it over the stock SH.

iammancini · 06-10-2011, 08:11 PM

Ok I'll try the atts unit from the type s and let u guys know. I'll post for future people who swap

iammancini · 06-23-2011, 07:17 PM

does anyone know if i have to take the oilpan off to get to the crank sensor. My mechanic asked just to make sure or else we will have to buy a new oil pan gasket. Not a big deal just preparing ourselves