One of the mods was an LSD. When I drove my brothers civic with a swapped out S80 Integra gearbox it felt very impressive around the corners and gave me the urge to get it done on the Lude. So I asked Rich a few questions regarding fitting an LSD, either an Mfactory helical item or an ATR type from the U2Q7 gearbox.
Rich says: The U2Q7 LSD will fit directly into an M2P4 gearbox. The M2P4 crown wheel will need to be swapped over onto it and the speedo drive gear or complete VSS will be needed from an ATR also as the drive on the LSD is different.
New diff bearings and output shaft seals are required, also require shimming to match the box.
Other notes Rich mentioned: Any time a component inside a gearbox is replaced whether it be mainshaft gears, counter shaft (final drive) or diff the related area needs to clearance checked. So for example if it is just the diff being replaced then the diff bearing preload or clearance needs to be checked/adjusted with the use of shims. Every gearbox is shimmed from the factory and every box is different. Sure you can just throw a diff in and not shim it but that is not the correct way to do it….although I’m sure many people overlook that because it takes time and patience !!
I went with the mfactory products as it was easier to source, and also whilst the gearbox was open I went for the 4.64 final drive change too. The final drive does dramatically change the characteristics of the car. It accelerates alot faster although cruising rpm is higher. At 70mph it is now 3900rpm insetad of 3600rpm. That said, it doesnt bother me too much as the Prelude isn't used daily although I do commute occasionally with it.
It does make it great fun drive, bearing in mind my h22 engine is pretty much stock, the prelude comes alive.
If the car is driven daily then the final drive would be abit too aggressive and the fuel consumption will noticeably suffer.
Ive not felt the accord u2q7 LSD but the mfactory helical LSD i have heard is slightly more aggressive than the ATR one. When driving normally (commute to work) the LSD is hardly noticeable. When manoeuvring, parking or just turning at a set of traffic lights you will hardly notice its there.
However, when you accelerate hard, the power is instantly transferred to the wheels. There is very little wheel spin and the car is pretty stable. When taking corners it feels like it wants to pull you around, there is very little under steer. Quite literally it feels like the car is on rails. The LSD does come alive on track though.
I would highly recommend the LSD upgrade, as the gearbox is out a final drive upgrade would be ideal but that's a personal choice. it depends on what you want from your car and how often you go for long motorway runs.
Hope i have helped
Few images of Rich installing my LSD and Final drive
Standard diff left vs Mfactory Diff right
All installed in gearbox
. If it's still there I'll have a nosy.
