[stick]

As some of you may have noticed, I have been spending a lot more time lately focusing on the drivetrain end of things. I am about to embark on a mission of creating the Uber-transmission (ultimate transmission).

Traditionally, the Uber L3 transmission has been a combination of ZC 1-4 gears, Si or HF 5th, and the final 4.437 drive from a JDM Integra ZXi.

I want to go one step beyond that with the transmission that I am about to build. I am planning on using ZC 1-4, an HF 5th, an SRR 4.9 Final drive and a Quaife ATB differential.

The 4.9 final drive should make the gears 1 - 4 25% shorter than if I were driving with a ZC transmission with the stock 3.88 final drive. I am opting to use an HF 5th gear because it should keep the RPM's about the same as if I were using an ordinary Si 5th with an Si final drive. I don't want to sacrifice my highway fuel economy.

Any comments/suggestions on other ideas for this project?

 

[akirarex]

I didn't know a 4.9 final even fit in the case, I thought the exospeed 4.73 was the largest.

 

[stick]

I didn't know a 4.9 final even fit in the case, I thought the exospeed 4.73 was the largest.

It's a brand new product. SRR is releasing 4.7 and 4.9 final drives for the L3 transmission (88-91)

 

[toxiclows]

Sheesh.... that is going to be one stout tranny.... Ill bet that thing bolted to even an hf would produce a litle neck snap.. .

Chris

 

[stick]

That's part of the plan too... if my car eventually goes turbo and gets significant horse power, I'll switch to an HF tranny to spread the gears out a bit.

 

[Kwicko]

Keep us posted and updated. If you don't mind my asking, what are those SRR final ratios selling for?

That certainly DOES sound like an uber-tranny. We've been tracking down and putting together parts for our own "superHybrid" for a while now - the 4.43 final isn't that easy to get hold of if you're not near the importers, where you can check things out and verify the ratios before you buy... I *did* get lucky in the last bunch of ZC transmissions we bought, though - one of the ones they sent us has a KAAZ limited-slip diff in it! David and I are still kind of fighting over it; I want it for my '91 DX - I want to replace the hybrid transmission I've got (ZC 1-4, HF 5, Si FD/Diff) with the new Super (ZC 1-4, HF 5, 4.43 FD, LSD, and intermediate shaft to calm down the torque-steer). David wants Effin to use that one in an unspecified "future project car". I'm kind of at the point where I don't really WANT any more project cars until I finish at least a couple of the ones I've got!

But seeing as that future project is being thought about as an autocross/track-only car, the 4.9 FD starts looking pretty sweet. Close gears and an ultra-quick final could make it go through the gears like a sportbike!

If you haven't driven a hybrid transmission with the HF 5th gear yet, try one before you commit. I love it, but there IS a pretty good drop in revs on the 4-5 upshift. It's fine for me, because I tend to use fifth more as just an overdrive or highway gear, not for accelerating. If I still need to have it floored by the time I'm shifting into 5th, the cops have already radioed ahead!

Mike

 

[stick]

Keep us posted and updated. If you don't mind my asking, what are those SRR final ratios selling for?

I'll definitely post updates as this project progresses. I think this is probably going to be my early summer project...so I'll probably have everything all together by mid-July.

They are going for $475 US. SRR has been making the 4.7 final drive for a while now, but they just recently added the 4.9 to their line up.

KIWI on Honda-Tech is the distributor for this new line of final drives.
http://honda-tech.com/zerothread?id=1227091

 

[Charles]

If you haven't driven a hybrid transmission with the HF 5th gear yet, try one before you commit. I love it, but there IS a pretty good drop in revs on the 4-5 upshift. It's fine for me, because I tend to use fifth more as just an overdrive or highway gear, not for accelerating. If I still need to have it floored by the time I'm shifting into 5th, the cops have already radioed ahead!

Mike

I love my hybrid tranny that has that setup. The 4th to 5th really isn't that bad and it sure makes highway cruising pleasant. Even at 90 mph or better the engine isn't really straining.

 

[Kwicko]

Maybe Charles can verify this, or maybe it's just me, but...

After years of crusing on the highway at my typical 80mph, the *sound* is permanently stuck in my brain; I tend to drive on the highway (conditions permitting, of course) more by the tach than the speedo, and to me, 4000rpm just seems "right" as the highway cruising speed. So now, with the HF 5th, 4000rpm isn't 80mph anymore - it's closer to 90! This has gotten me one ticket already, and damn near a few others; thankfully a Passport detector fell into my lap recently, which has saved me $.

Anyway, has anyone else noticed this phenomenon? Does anyone else cruise more by tach than speedometer? Or is it just me? I'm constantly looking down now and being surprised to find myself doing 88mph or more. Most cops around here won't look twice if you're doing 80, but when you close in on 90, you're going to get it.

Mike

 

[Charles]

I go by the flow of traffic more than anything else. There's always some teen hauling ass around here. If not, then I do go by the engine sound/tach. I really don't look at the speed at all. That's why I will look down on a long trip and think, "Wow, 95 mph. Didn't realize I was going that fast."

I don't have a radar detector as I still got tickets with it. Since getting rid of it several years ago I have only received one which was dismissed after deferred adjudication. My record is still clean at this point. (knock on wood)

Kwicko is right, that HF 5th sure allows for a fast cruise. And the ZC 1-4 paired with ths Si final has a habit of encouraging jack rabbit starts. So I guess it is just plain difficult to granny drive with the hybrid.

 

[akirarex]

I am a tach guy all the way. I have a dohc zc with a hybrid trans but the si fifth gear not hf. That spot at 4k is really nice and it hums nicely too. I think that cars have a sweet spot in how they are geared and powered to create a band of rpm's that you could say that the car wants to be driven in those ranges. Tach watcher all the way, as soon as it starts creaping over 4k I let off ever so slightly to maintain 4k.

 

[Kwicko]

Whew - I was starting to wonder if it was just me! Akira, you're right - 4000rpm just feels like the perfect sweet-spot for the CRX engine. The HF 5th doesn't change that sweet spot - just the speed at which it's maintained! 4000 still feels like the right spot for a highway cruise. It's weird - I went with the HF 5th because I wanted my revs to be a little lower on the highway; I figured since I always tend to cruise at around 80mph, then the HF overdrive would drop my revs to around 3600rpm at that speed (it does, but closer to 3700rpm). Instead of cruising at 3600-3700rpm, though, I still end up at 4000rpm - because that's where the ENGINE speed wants to be, regardless of my wheel speed!

Guess maybe the car knows more about what makes it happy than I do...

Mike

 

[stick]

Correct me if I'm wrong, but I was doing a little bit of calculation, and a transmission with a 4.9 final drive and an HF 5th will have almost exactly the same RPM's as the 4.25 final drive with the Si 5th. I think it was only off by about 50 RPM's or so in my calculations.

 

[akirarex]

It's also nice for the zc engine to be at 4k because that is when it starts gettting "on cam" it seems. So at that rpm you can punch it and it moves nicely to pass the slower traffic.

Stickershop you should post a pic with that nice big final drive in the trany case. I would like to see how much gap that is left in there, I bet you have to get the feeler gauge out to make sure it won't rub lol.

 

[Kwicko]

Sticker: You're probably right, but there will still be a larger-than-usual gap between 4th and 5th, just because of how widely spaced they are with a ZC 4th and an HF 5th. Likely the 4.9 will minimize the effect, but I think you'll still notice it - just not as much as you would with the 4.25 final.

And if I could have a 4.9 final and a 4000rpm cruise at 80mph in 5th, I think I'd be all over it.

Mike

 

[stick]

And if I could have a 4.9 final and a 4000rpm cruise at 80mph in 5th, I think I'd be all over it.

Exactly my thoughts on it. I'll double-check all of my math and let you guys know how it turns out.

 

[Kwicko]

Akira: Makes me want a ZC... My A6 engine mated to the HF 5th gear does a bit of an odd thing: it gets up on the cam up at around 4500rpm - which is around 105mph! It's a weird thing - you're accelerating, but just smoothly, easing up the speed, and then you can feel it start pulling stronger and stronger. I don't know where it runs out; I've chickened out around 115-118 mph indicated every time I've tried it. I'd love to find out where the air drag overcomes the "awesome" power of the Si engine, but I'm getting too old and "mortal" to try it.

Mike

 

[akirarex]

I like a6's over zc's. They just drive better and have more torque down low for nice city driving.

 

[daveb91]

This is when we need Mista Bone.

 

[Kwicko]

This is when we need Mista Bone.

Anyone contacted him and invited him over? I won't say *everything* I know about transmissions was learned from him, but a good deal of it was!

Mike