Prelude Type O

Was reading a lot about the ATTS unit on the SH trim and I saw that the ATTS unit carries three small clutch disks. The pictures are in someones thread page. The owners name of the thread starter: Revi
Link: https://honda-tech.com/forums/honda-...nside-1858351/

Would be pretty interesting if I took my ATTS apart and sent the clutches to a local clutch shop to see if they can do custom fabrication so it could withstand boost.
ATTS cuts itself off around 250ft/lb of torque. I wonder if it cuts off because of the stock ecu or because the clutch disk just slip at that point.

TimiK

it would be alot easier (and more reliable solution) to get mechanical LSD there with Hondata than start to play around with ATTS and OBD2 electrics

Prelude Type O

Man... I should just go all motor for my Prelude SH then. That way I can just get another 5th gen prelude and drop a jdm H22a and boost that one. What about GReddy e-Manage Ultimate (black box) and how well it piggybacks force induction?

TimiK

neptune or hondata (REAL engine management) only Id say - wouldnt trust those others

sell your SH and get another lude or sell just the engine from it and get base engine to play with

motoxxxman

I've tuned several boosted h22's with emanage ultimate. It actually works very well when done correctly, and passes emissions in most states. good luck finding one though.
I've also done a twin ecu setup on an Auto SH prelude with a turbo; stock obd2 ecu and hondata ecu. It basically was a jumper harness and a conversion harness, where all inputs fed both ecu's, and only the hondata ecu had the outputs for injectors and igniter. It was solely meant so it could remain an auto but be fully tuneable. I'm actually surprised how flawlessly it worked.
as for the atts, its because they slip. and building it up I don't think would help, because the computer would need to be reprogrammed for it and thats not possible.
It's odd that you found the magic number of 250ft/lbs, because all 3 SH preludes I've tuned that reached that area for power all got the atts light and disabled it at almost exactly 250tq as well.
I'd say go n/a with the SH, and get a normal base model for boost. the SH's are heavy as hell too, not the greatest for racecar.

snobordboy

Just to add more food for thought here, but when dealing with a modified Honda, especially turbo, you are generally going to need to be doing more maintenance, and being very hands-on with the car. In the respect, the SH is a pain with the big ATTS unit back there, making axle and clutch work much more difficult, as well taking up space at the rear of the engine bay, and being very heavy as Motoxxxman said.

If you do not need the car to pass OBD emissions via a plug in test, dropping in a base model/ JDM engine and tranny setup and then tuning via OBD1 setup, would be much more flexible and easy to deal with. Personally I think there are the other small benefits that many don't think about at first, like not having wiring for the crank sensor down by the oil pump, etc that are also plusses of the obd1 swap.

Prelude Type O

When you say the atts disables itself, you mean when you tuned the SH on the dyno right? When it reached past 250ft/tq the light turned on and then after the pull the light turned back off or stayed on?