sk8shorty012

iTrader: (3)

With my current transmission setup (4.785 final drive / 0.848 fifth gear) I would be at 4653 RPM at 80mph.

The OEM setup (4.4 final / 0.848 fifth) is at 4278 RPM at 80mph.

My question, is the extra 300 RPM too much for the motor to handle?

I'd prefer the extra "torque" of the 0.848 fifth, but don't want to cause damage to the motor as I do numerous drives to San Diego (2.5 hours one way) at 80 mph for most of the drive.

So is it bad to be at an additional 300rpm over factory specs for such a drive?

The car is a 1999 Honda Civic EX, with a factory B16A3 swapped in.

EJ8_Man

It's more wear on the engine of course, but it wont hurt it in the short term. You'll get less life out of it. I have a S80 JDM Type R tranny and I'm buzzing up around 4500 at 80 mph, which is why I don't commute in my type R

sk8shorty012

iTrader: (3)

With the JDM tranny, you'd have the GS-R 0.787 fifth and still @ 4500 RPM wow.

So basically, is the extra 300 RPM not worth the extra 10% torque?

ddd4114

An oil cooler would not be a bad investment.

ddd4114

I guess I don't see the reason you want a shorter 5th gear. Can't you just downshift when you want the extra torque?

BSFC will probably get worse when you're revving that high, depending on your engine and tune.

BryanM.

iTrader: (1)

Like someone else said, short term it will be OK. If it's a bone stock Honda
assembled engine, you may be able to drive like this for a long, long time.
If you're that concerned and you frequently commute on the highway for long
distances, think about switching to a 5th gear from a B18B transmission.

Or, here is another concept: SLOW DOWN. You do not need to travel at
80 mph, I don't care where you live. Not necessary. Leave the house a few
minutes earlier if you have to.

GTFO ok

lazlong

lol. Come live in Texas for a couple years and you'll change your mind on that one. Everything is miles away here.

Libertariat

300rpm isn't going to make that big of a difference.

I'd recommend cruising at the speed limit instead, and perhaps investing in an oil cooler.

You could go 70 or 75 and you won't get there that much slower than doing 80mph. what's 4-5mins?

sk8shorty012

iTrader: (3)

I do have the OEM Type R Oil Cooler installed already.

The only reason I say 80mph is because that's the maximum speed / RPM in 5th I'd be at, so it's to put the question in the worst case scenario not that I'd be at that speed the whole trip.

As far as downshifting, I was just saying I'd rather be able to accelerate in 5th (shortest gear ratio) without having to downshift, but not at the cost of the life of my motor.

h22accord101

just do like dude said above go out and get your self a bad ls trans that 5th gear is good in and put the ls 5 th gear in your b16 you will have shorter gears and a longer 5 th gear for highway

h22accord101

^^^^ best solution have had many friends do this

sk8shorty012

iTrader: (3)

I'll probably just compromise and do the 0.787 GS-R fifth. Still some acceleration, but not as bad as the 0.848 RPM wise.

Red_Army

slow down. yea you can go 80 but why not just chill at 70.

hah at texas. live in the midwest. theres nothing anywhere. and i can drive 60 all day just fine.

sk8shorty012

iTrader: (3)

There are certain sections between LA and SD where the speed limit is 75.

ktsciv93

5th gear pulls anyone?! lol

but ya the gsr 5th is probly ur best bet for what ur looking for it seems...

sk8shorty012

iTrader: (3)

it's not even about pulls, it's about being able to accelerate up a hill with a 1.6L without having to downshift to 4th.

ktsciv93

bro i have a b16a2 with a b16 tranny in my 93 eg. and i live in pa. u have no idea about hills...

sk8shorty012

iTrader: (3)

WHAT

itsnotfast

I kinda agree, but hes talking about long steep inclines on the highway in CA. In PA we have HUGE hills but they're not as long but in most cases are more of a climb.

I've been to LA and SD and the hills are there but they don't compare much to the hills/mountains in PA but like I said our aren't as long. I took my GSXR up in the Pocano Mountains 2 years ago, stayed in 1st and 2nd gear most of the time.

8YourV8

I love my GSR transmission. 4050 at 80 mph

itsnotfast

I love my GSR as well but I would MUCH rather have a LS 5th. I live in Delaware now and pretty much everywhere around here is flat as hell.

B serious

iTrader: (1)

No, its not too much for the engine to handle. You could also go 75mph if you're worried. Might be an easier solution than an oil cooler and gear swap and flux capacitor or whatever people were mentioning up there.

WeakSauce92

I love my cx transmission. 2600 at 70 :D lol I love my sohc. I can't imagine being over 3k for an extended drive... too much noise for me.

92civlude

LS 5th is the way to go.

AutoXer

I'm not sure you'd be able to do that even with the final drive ratio you're looking at. I drove my EK all over the northeast, mostly on highways crossing one mountain or another, and I would have to go to third just to maintain speed sometimes. Without actual torque, you're probably going to have to shift (I can't imagine 300RPM would make that much difference anyway.)

As for the 300 RPM, it won't do anything substantial to a well maintained engine. I've witnessed many tranny endurance tests when I was in the industry, where they would run motors at redline all day, every day for years and not have a problem. As long as there's a film of healthy oil between the moving parts you won't have a problem.