Review for Quaife LSD & Custom Houseman 4.85 Final Drive
----------------------------------------------------------------------------------
Background
I recently swapped in a new transmission to replace my old one that was in dire need of new synchros.

The old transmission was a stock M2Y4 with an open differential and stock final drive. The 2nd gear synchro was so worn that shifting into 2nd was only possible if the revs droped down to about 1k and then shifting slowly. That or just rev 1st a little high and jump right into 3rd. Both were not much fun to do. 3rd gear was starting to go under high RPM quick shifting as well.

So, it was time to either replace the synchros or just buy a race transmission from a former world challenge racecar. After thinking it about it for a few long seconds, I decided on the race transmission.

New Transmission
This new transmission is a M2F4 that comes from the 4th gen H22A1 VTEC model, although this one was installed on a 5th gen, as pictured above. It features a Quaife Limited Slip Differential and a 4.85 custom Houseman Final Drive.

The M2Y4 and M2F4 have nearly the same gear ratios with the exception of the 5th gear on the M2F4 being slightly shorter.

By shorter I mean for example: At 80mph in 5th gear, the 4th gen tranny will be at a slightly higher RPM than the 5th gen. The 4th gen tranny will also have a slightly lower top speed.

LSD - All about the Quaife Limited Slip Differential
The purpose of a limited slip differential is to power both drive wheels instead of just one. With an open differential, power shifts to the wheel with less grip. The LSD, on the other hand, senses which wheel has the better grip and biases the power to that wheel.

The real world indications of this include:
Wheelspin is reduced under acceleration and turning. Just launch the car and it pulls away flawlessly.

Hard launches create a nearly 50/50 power split to both drive wheels, resulting in essentially twice the grip of an open differential. This completely eliminates the peglegging effect that open diffs are infamous for.

LSD also improves handling by transmitting more power to the outside front wheel while turning causing the car to achieve much higher cornering speeds. This is similar to the effects ATTS produces, however ATTS is electronic and doesn't work as productively or seamlessly. ATTS is also only prevalent under spirited turning situations and not straight driving or launching. This makes LSD far superior.

A LSD greatly helps a FWD car handle much less FWD like. By that I mean much less understeer, with oversteer ability even, and ultimately a greatly enchanced automotible handling experience.

Driving Impressions
-----------------------------------------------------------------------------------------------------------
The Final Drive
The purpose of a larger final drive is to make the gears shorter. Shorter gears make the car faster, but also give the car a lower topspeed. As expected, this Final Drive does just that.

The gears are very very short. Maxing out my 5th gear is about the same speed as maxing out a stock transmission's 4th gear - About 120mph. In effect, each gear feels about as powerful as one down from it. 5th feels like stock 4th would. 4th feels like stock 3rd would, etc.

1st, well, 1st is just amazingly fast revving. VTEC engages and the RPMs shoot to reline before you can even have time to react.

I was plesantly surpised by how close these gears are. It feels like a completely different car now. It's as if there are no dry spots of power. You are always in the power band and/or very close to engaging VTEC, if not already there.

At 70mph in 5th gear I'm at about 4100 RPM. At 80mph that raises to about 4850. Mind you a stock transmission's final drive would yield about 4k RPM at 80mph in 5th. So this is quite a difference. It's almost motorcycle-like, well, not that high. It is considerably higher, as you be cruising along as 4k RPM and only going ~67mph. Driving along in the neigbhorhood, 3rd or 4th gear both have enough power to pull the car around at 25-35mph at about 2000 RPM.

There are some bad things about a shorter final drive. With shorter gearing comes a higher revving engine. Gas milage will suffer from the engine having to rev more to go the same amount of speed as before. Just how much more, I'm not quite sure yet. I'll update this review with gas milage once I get some more results.

Also, top speed goes down. The stock top speed on a 5th gen is somewhere around 140-150, which is always debatable because the stock tach is inaccurate at such a high speed. Nevertheless, that is the assumed top speed.

With this new Final Drive, the top speed has been reduced to about 120. I haven't maxed out 5th gear yet, but I am speculating it to be around this speed.

EDIT: Top Speed with Stock Wheels and Tire Size (205/16/50) : 130mph*

*Unaccurate stock speedo, but it's good enough. All test performed on a closed course. Do not attempt at home.


This isn't neccessaraly a bad thing, because when do you really need to go 140 mph? Most Honda club race cars don't even get up to this speed. Fortunately, I could run say a 225/50/16 tire and slighly increase the overall wheel/tire diameter to create a little bit of extra gearing for a higher top speed. This would be particually helpful at TWS with that famous long front straight. Plus any other track with a long straight.

More LSD
The LSD is just wonderful. It's very seamless. Just turn as you normally would and you'll notice you can lay a bit more throttle on than before and the car just rotates around perfectly. It surprised me at first as I oversteered.

Launching, as I said earlier, is much simplified. Hardly any wheel spin is present as the car comes alive from a stop.

I currently have worn crappy Kumho 711 tires, so any attempt to push the car and really test the lsd tends to just make them slide around. I'll be able to give a better review of all the effects the lsd has after geting a better set of tires.

More to come later....

Lots and Lots of Numbers
-----------------------------------------------------------------------------------------------------------
Transmission Gear Ratios
Here are the different gear ratios.

1st is the stock 4th gen VTEC Transmission
2nd is the stock 5th gen Transmission.
3rd is my Transmission.

4th Gen M2F4:
1 - 3.307
2 - 1.950
3 - 1.360
4 - 1.071
5 - 0.870
FD - 4.266

5th Gen M2Y4:
1 - 3.285
2 - 1.956
3 - 1.344
4 - 1.034
5 - 0.812
FD - 4.266

New Transmission:
1 - 3.307
2 - 1.950
3 - 1.360
4 - 1.071
5 - 0.870
FD - 4.85
-----------------------------------------------------------------------------------------------------------
Final Drive
Stock / New
4.66 / 4.85
-----------------------------------------------------------------------------------------------------------
Below are the speeds at which each gear would max out at:
Old Redline Speeds
~ = approx
Gear / MPH
1 - 40
2 - 65
3 - 95
4 - 125
5 - ~145

New Redline Speeds
Gear / MPH
1 - 35
2 - 58
3 - 83
4 - 100
5 - ~120

A picture form for you visual learners:

Redline MPH Graph
Blue = Stock
Red = New
Each subsequent colored line represents a gear.

Note: Don't mind the redlining tachometer and excessively toped out speedometer. The car wasn't even on.
-----------------------------------------------------------------------------------------------------------
These are the approximate VTEC crossover points with a stock ECU:
Old VTEC Engagment Speed
Note: Stock VTEC Crossover
Gear / MPH
1 - 20
2 - 40
3 - 60
4 - 80
5 - 100

New VTEC Engagment Speed
Gear / MPH
1 - 20
2 - 35
3 - 58
4 - 73
5 - 85

^^ I'm thinking I need to try to measure 1st again. It moves so fast, it's hard to see when VTEC engages for that one. It's somewhere around there.

EDIT: 1st gear VTEC was in fact lower after all. 20, not 22.

And another picture for the visual people:
VTEC Engagment Graph
Blue = Stock
Red = New
Each subsequent colored line represents a gear.

-----------------------------------------------------------------------------------------------------------
New Cruising RPM in 5th Gear
MPH / RPM
70 - 4100
80 - 4850
-----------------------------------------------------------------------------------------------------------
The End, for now.


Modified by Paul H22A4 at 11:19 PM 9/29/2005


Modified by Paul H22A4 at 11:32 PM 9/29/2005

 

that's pretty damn sweet. how much did you spend on each component if you don't mind me asking?

 

I bought the entire transmission for 1200 shipped. It came with the LSD and FD installed.

 

that is a steal congrats....you must be an accelerating maniac now

 

good info. will constantly higher revs cause anything other than worse gas mileage?

 

hey thats my mechanics old lude the poor thing is sitting out side of the shop in pieces i wish i could have bought that h23 vtec motor and tranny but thats just how it is when your broke as a joke

good info man

i love my quaife i just hope im not hurting it by haveing 2 different types of tires on it one that grips good and one thats cheaper than the type that came factory on my lude

 

can you make a comparison btwn stock and this tranny's accel? like 0-30 ect ect

- wow now if i was you...id be wanting a nice 6th gear

 

you already installed that transmission with out me??!?!??!?!?


haha, LSD rocks huh??

 

Nice writeup, thanks for posting it! I'm happy to see a thread like this...

 

isnt it sweet paul, i love my tranny.....

i didnt get this deep with mine, but you are better off on the highway than me, my 5th at 80 is like 5k....its weird to cruise there, im in and out of vtec with like 2mph adjusments, great for passing though....

 

Dude, that is WAY to low of gearing, even for racing! I can't imagine a M2F4 with that low of a final drive. Arn't you going to be racing that car? 120mph top speed you will be hitting the rev limiter down the straights easily.

Corey - who would never think of putting a lower FD in a M2F4.. In a M2B4 and M2Y4, yes..

 

is this a street car??


bad *** tho

 

This thread is kick ***, great work!!!

 

A race prepped prelude can hit 120+ at most of the tracks I have been to. On a 5th gen tranny a 4.7 FD would be better IMO. However at $1200 for tranny with LSD and new FD is a steel! At that price I would run it and see if you run out of top speed. If you do then just get a new FD gear.

 

Great write-up.

But damn, that's some reeeeeeeeeeeeeeeeeeeeeeeeally short gearing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Honda318dx &raquo;</TD></TR><TR><TD CLASS="quote">Dude, that is WAY to low of gearing, even for racing! I can't imagine a M2F4 with that low of a final drive. Arn't you going to be racing that car? 120mph top speed you will be hitting the rev limiter down the straights easily.

Corey - who would never think of putting a lower FD in a M2F4.. In a M2B4 and M2Y4, yes..</TD></TR></TABLE>

i can hit about 130 in 5th before 7500, but i dont have my limiter set until 8....no i dont know this from street driving....get out the calculator....

anyways....good stuff...

 

Thanks for the writeup on the Quaife, just solidifys my idea of wanting one of these

 

It's a bit quicker now. Having 2nd gear is nice too.

I hope not.

Indeed. The former transmission of the Lockwood World Challenge Prelude.

I wouldn't think running two different tire types would affect your diff. It's a good idea to run 4 of the same tires though.

Glad ya like it

Yes, it's great. That is strange though. At 80mph in 5th I'm at those same RPM's... this makes me come to think the FD may not be 4.85 and maybe something longer.

Sam Lockwood said it was just about the largest Final Drive they could fit in there, but could not tell me the exact Final Drive number. I should call him up tomorrow and see if he could ask his brother, Grant more about it.

If the gearing is too low, particually the low top speed, I could take the 5th gear off my busted M2Y4 and swap it over. Also, I plan to run 225/50/16 tires, which make the gears slightly longer. There will be no 15's on this one. I would top out at 115 or something...

Yes the plan to be racing the car eventually. HC H2 Rookie Season ETA: 2009...!! Yeah, I kidd, I kidd. I have no idea when I'll actually be ready for competition.

Currently, yes. It doesn't see any extended amount of highway driving.

The price was excellent. Like I said in response to Corey's post, I may change the 5th gear to make it essentially a M2Y4 again, if larger tires do not give me a high enough top speed.


Thanks. I'm really enjoying it.



Thanks

It's hard to gauge because I didn't have the ability to shift into 2nd very well with my old tranny. It is definately faster, I just don't know by how much.

6th gear would be great.

The car feels like it doesn't have a 5th gear now. Sure, you shift through all the gears, but the top of 5th feels like 4th would.

 

Again, if you do ever plan to race in H2, you have to use a 5th gen tranny to be legal, so take that into consideration down the road.

A M2F4 has sweet stock gearing. In H2 trim on the front straight at summit point, with stock gearing, I hit the 7500rpm rev limiter, as well as LMS.

Now the car is in H1 with stock gearing and +25hp.. I had to raise the rev limiter 800 rpms to not run out of gear..

Sorry, but I just REALLY feel thats too short, and you will be shifting (each shift looses time) more than you should.. Granted, the acceleration in each gear would be kinda sweet..

I also talked a friend that races H3 to NOT get that tranny/fd. It would have put him at lke 110mph top speed..

 

oh yeah i forgot that the stock f4 5th gear is .870 instead of the a4/b4 .787....

thats why the top speed is so low, maybe you can find a shitted a4/b4 to scavenge a gear from....or maybe your old tranny gear would do it...its not quite the .787, but .812 is better than .87....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">oh yeah i forgot that the stock f4 5th gear is .870 instead of the a4/b4 .787....

thats why the top speed is so low, maybe you can find a shitted a4/b4 to scavenge a gear from....or maybe your old tranny gear would do it...its not quite the .787, but .812 is better than .87....</TD></TR></TABLE>

b4 and y4 are .812..

The accord trannies (and some JDM H series) trannies have the shitty .787..

 

according to the faq, the only jdm h trannies that have the .812 are the 5th gen....

it says .787 for the a4 and b4

 

Maybe I'm confused.. B4 is 4th gen SI right? Y4 is the 5th gen base, correct?

Edit: Just checked, I was saying B4, but what I meant, was S4, sorry about the confusion and I stand corrected, thank you..

 

I bet a tranny like that would work really well at our local track. I really have to hit it hard to use 4th gear in a M2B4. The Quaife was quite noticable on this track too.


http://www.sandiamotorsports.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Honda318dx &raquo;</TD></TR><TR><TD CLASS="quote">Again, if you do ever plan to race in H2, you have to use a 5th gen tranny to be legal, so take that into consideration down the road.

A M2F4 has sweet stock gearing. In H2 trim on the front straight at summit point, with stock gearing, I hit the 7500rpm rev limiter, as well as LMS.

Now the car is in H1 with stock gearing and +25hp.. I had to raise the rev limiter 800 rpms to not run out of gear..

Sorry, but I just REALLY feel thats too short, and you will be shifting (each shift looses time) more than you should.. Granted, the acceleration in each gear would be kinda sweet..

I also talked a friend that races H3 to NOT get that tranny/fd. It would have put him at lke 110mph top speed.. </TD></TR></TABLE>

If changing my tire size to 225/50/16 doesn't give me a high enough top speed then I will explore the option of changing the 5th gear and/or final drive back to M2Y4 spec.