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Discussion Starter · #1 ·
Because I'm in Germany, I drive on the autobaun almost every day. The only problem with this is that my higher gears arn't tall enough. :cry: I have done 130-135mph, :D but the rpms are at about 6200. :x Now I don't go that fast usually but when 90-100 is the norm. It would be nice to have either a 6th gear or a taller 5th gear. Because doing 80-90 at 4000 rpms is getting old. I don't know how many of you guys have thought about this but I need a way to get taller high gears and keep the first three gears just the way they are. Or mabey if there was a way to just add a 6th gear for cruising without spending too much cash.
 

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What engine do you have? (I'll assume D-series for the moment.)

There's no way to do 6-speed unless you have a K-series, so what you should look into is a 5th gear swap. This will require completely dismantling the transmission, so it's also a good time to buy a rebuild kit and replace all the seals and synchros.

I'm sure you can find an HF 5th gear set on ebay or Honda-Tech or somewhere, and if not you could buy it through Honda. Then drop by a garage that specializes in transmissions, and ask how much they'll charge for a rebuild. They should be willing to install the new 5th gear set for free, since it all has to come apart anyway.

The HF 5th won't increase your top speed by a whole lot though. It supposedly lowers rpms by about 300 at 80mph. Most of the HF's tall gearing is due to its final drive ratio. I'm guessing you'll have an extra 500 or so rpms to work with at 130mph. Another advantage to this is slightly improved highway fuel economy.

With the transmission coming out, this is also a convenient time to consider replacing or upgrading the clutch and flywheel. You'll be saving big on labor charges if you do everything at once.
 

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He could also install a different final drive to "lengthen out" his gears a bit. It really depends on what kind of transmission and engine he has in there right now.
 

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Discussion Starter · #4 ·
You are right. It is a d series engine it's a d16z5 if you've ever heard of it. I'm not made of money right now so I'll have to wait a while on replacing the 5th gear and rebuilding the tranny. I don't think just doing the 5th gear will be enough. If I do that and work with the final drive ratio that could do the trick. Because I would like to lower the rpms alot more than 300 to 500. somthing more lick 1000. I know its steep but its killing my gas mileage to be doing 4000 to 4500 rpms on the autobaun all the time.
 

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stickershop said:
He could also install a different final drive to "lengthen out" his gears a bit.
You're exactly right. He said he wanted to keep the first few gears the same though, so that's why I didn't mention it.

What I'm thinking you should do, is get a ZC trans and put the HF 5th in there. I'm assuming that the Z5 you have is coupled to what is basically a US Si trans, which has the shortest final drive. The ZC trans has a FD equivalent to a US dx, but with real short gears. So, the "medium" FD combined with the short ZC 1-4 gears will give you the acceleration you want, and the HF 5th will have a larger impact through the ZC FD. I don't know the exact ratios or I'd compute it for you.

Or, maybe your trans is already equivalent to a ZC. Where's SETI? He should know.
 

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Hey bro! cool hang out. Your best bet is to get a taller top gear. you start screwing with the final drive there goes any responsivness you would have had. God knows you need all the gear you can get with your torque curve! :lol:
 

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Even if you put taller gears in, you will run into the problem where the power of your engine is equal to the wind resistance at high speeds, and you just can't go any faster. Putting in taller gears decreases torque multiplication so it'll take you forever to accelerate even a little bit at those speeds. i think the solution to driving a crx at 130 on the autobahn is to do a motor/trans swap.
 

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The d16z5 is a DOHC D, basicly a DOHC ZC, so he should have a ZC trans. I think a US Si or equivalent for over there would help a bit unless Im mistaken (Its also 1:30am) on the gearing being a bit higher in the Si, and a bit lower in the ZC trans.

http://www.housemanautosport.com/ratio%20calculator.htm

Nevermind..
zc:
3.25
1.944
1.346
1.033
0.878
FD 3.888

si:
3.25
1.894
1.259
0.937
0.771
FD 4.25
 

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Make the car more efficient first.
Lower it a bit, get some of those spoon replica mirrors, and put on one of those EE8 rear wings. (They DO help keeping the ass planted)

Make some more power.
Sort out the header and exhaust so you can push into the upper RPM range easier.
Once you're there, just shift the rev-limit up a little.
That oughta get you 10-15Km more.

Oh and for gods sake, put some EE8 brakes on if if you're gonna do these speeds. Stock crx brakes will kill you, no matter what those yanks say. They're not used to speeds like that.
 

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CrxCarl said:
Wouldn't it just be cheaper all around to slow down.
Save money on gas and the transmission.
Just a thought.
HA HA! Oh man, that's funny :lol: .
 

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Discussion Starter · #14 ·
You don't have to worry one bit about my car being lowered. In fact it's too low. When I go off base I feel my entire shifter assembly move when I go over the two speed bumps on my way out. And there is no way to avoid them. That ain't good. But I will say that coming out of the traffic circle near the base is intense because as I take the sharp 100 degree right my car stays totaly planted. I think I pushed 45 mph just the other day. And by the way this turn is not to be taken lightly. The traffic circle is tiny, the road is narrow and the turn is very sharp. Its europe what do you expect?
 

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Discussion Starter · #15 ·
Oh yeah, and as far as the autoban goes, you can do 60 mph and you'll be fine. See, at least half of the autoban has a speed limit of some kind. The highest speed sign there is is 130 kmph which is abou 85 mph. And thats pretty standard. The lowest is legal speed is 60 kmph. Thats only 31 mph. You usually only get that over bridges and in road work areas. Then of cours is the no speed restriction areas where the average speed is about 80-100 kmph. The only time its dangerous for the people going 60 mph is if there in the left side of the highway. By law the slower vehicals half to go to the right if a faster vehical is coming or they could be killed. Believe me its hard to take the car from 120 to 60 in a short amount of time because the slow guy won't move.
 

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I've heard of people swapping in the final gear from an LS tranny for cruising purposes, don't think it would be very helpful for trying to hit higher speeds faster, but at least you won't be at 6000rpm.
 

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CRX_2NV said:
I've heard of people swapping in the final gear from an LS tranny for cruising purposes, don't think it would be very helpful for trying to hit higher speeds faster, but at least you won't be at 6000rpm.
solman said:
It is a d series engine it's a d16z5
they just won't work together...
 
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