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4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Mon Jun 16, 2014 10:49 pm
by BrianZ
Hi guys, I am new to ae86, about to pick up a GTS.
But since the gts has a 4.3 rear end and it hits 60mph at about 3600rpm and 70 mph at 4k rpm
which seems a little high for me (it hits my OCD zone when it revs so high on the hwy)
I just want to know on a reliability point of view, if it is safe or "ok" for the 4age to do road trips since it revs so high on hwy?
Anyone has any experence ?
It would be my daily so road trips are unavoidable, it just has been bugging me for a while.

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Mon Jun 16, 2014 11:51 pm
by ZINCHOTRAN
I took my transmission apart and took the input and output shaft to a transmission shop to replace the synchros. They didn't check the gear thrust clearances and it was paid under the table.

So for over a year and a half I haven't been able to use fifth gear. So I've been in fourth gear upwards of 100mph with no problems while cruising back and forth between my apartment and visiting my mother. Round trips of 320 miles. Oddly enough when I stay around 5k rpm and it is around 70mph I still average 24mpg in fourth gear. If I keep it around 60mph I can get up to 28mpg.

It really depends on how delicate your foot is on the pedal. Pretend you have an egg under the gas pedal.

I'm sure others have similar experiences. The sound from the engine is SweeT!

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Tue Jun 17, 2014 12:39 am
by Zissou
A friend of mine had his AE sit and rot in a yard in LA for six years before he decided to give it to me. I flew down on a plane and drove it to Oceanside before turning back and driving it to Reno, which, all said was some where around 500-600 miles. Six year old oil, gas, tires, brakes, everything, and I ran it in one nonstop run at 70-75mph, and over Donner summit from Sacramento to Reno, no problems.

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Tue Jun 17, 2014 11:34 am
by -zenki-
If your engine is well maintained, the higher rpms aren't really a problem just noisy. Imagine what it would be for people with a 4.5/4.7 rear-end, even higher rpms.

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Tue Jun 17, 2014 12:31 pm
by Deuce Cam
Yeah I've got a 4.7 rear and rpm is roughly 4300 at 65 mph :(. The sad thing is I've got a longer mfactory fifth gear that's been sitting in a drawer for like a year and a half.

ZINCHOTRAN wrote:So for over a year and a half I haven't been able to use fifth gear. So I've been in fourth gear upwards of 100mph with no problems while cruising back and forth between my apartment and visiting my mother. Round trips of 320 miles. !


Holy **** :shock:

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Sat Jun 21, 2014 5:41 pm
by BrianZ
Brought it back, almost 300 miles.
But still, cruise at 3k-4k rpm hit my OCD zone real bad, haha.

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Sat Jun 21, 2014 10:08 pm
by ZINCHOTRAN
From what I've heard and read the 16 Valve 4AGE was developed to be like the Ford Cosworth engines.

Now don't think that all Ford engines and components are refuse. These engines love to rev. What you need to do is keep them maintained and well lubricated. Think about all the components and what will wear out faster than other parts.

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Sun Jun 22, 2014 7:58 am
by Snotcycle
if 3k hits your ocd zone dont drive an 86, miata, any motorcycle, or any two stroke; It all depends what the motor is designed for.

These arent some POS unbalanced v8 thats going to window the block after 5 minutes above 4k

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Sun Jun 22, 2014 8:23 am
by Deuce Cam
^Indeed, but in all fairness the national speed limit was only 55 mph when the ae86 was available new.

Even my old sti with a 6 speed was around 3500 rpm on the freeway around 70-75 mph.

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Sun Jun 22, 2014 11:34 am
by ZINCHOTRAN
Yep. When I did 55mph in fifth gear I'd achieve my maximum mpg of around 41mpg with the AE86 coupe GT-S. Slow and steady acceleration and coast when possible. Cruise control helped a lot too; but not always.

Re: 4AGE High Cruising RPM, Safe&Reliable or not?

Posted: Sat Jun 28, 2014 1:23 pm
by taroroot
It's a 4AGE, it lives for revs, heck 3600 is just starting to get into where it likes! Have good oil, good coolant system, you're all good.