How does your ka-t drive on the highway?

Basic tech questions such as future setups, different turbo kits, car diagnosis, etc
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AFKOUKI
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How does your ka-t drive on the highway?

Post by AFKOUKI »

Been doing lots of research on going ka-t and im somewhat apprehensive at times due to the kind of driving I do. I live on base and walk to work, but drive ~600 miles round trip on the highway on a monthly basis. At ~80mph and with a j30 diff my ka is exposed to rms >3k for long periods of time. Would this cause excessive wear on a turbo? Also, would I be in boost this whole time with a T25 or T3/4 (undecided ATM)? Sorry for the newb ?'s but this is all a learning process, Thanks
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Post by schmauster920 »

You can swap diffs and or run an oil cooler if you are that worried about it.

With power, i love my freeway gearing due to large tires.. stock, it would be painful
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Post by tom550 »

you wont see any boost when cursing at a constant speed. its when you step on the gas that the turbo will spool.

get a different differential. such as a q45 to lower your rpm at higher speeds.
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Post by AFKOUKI »

does the q45 have a different gear ratio? Im not really worried about the diff, but anything for better gas mileage I guess. Thanks for yalls imput!
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Post by 240-kid »

Just get the J30 and a Taller tire. Stock tire is ~24.6 so anything taller is gonna help you. Q45 is overkill for just gearing.
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Post by Kfred »

I have a turbocharged integra and it was made when the interstate speed limit was 55mph. When I am doing 80mph in 5th gear, my car pulls ~3750rpms :x. My 20 year old turbo and engine are holding up fine.

Turbos use a journal bearing, so as long as there is sufficient oil pressure and viscosity there should be zero contact. If you are worried about oil temps, buy a cooler as stated above. You can buy an oil temp gauge to see if you need the cooler,.
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Post by beercandrifter »

in response to original question:
How does your ka-t drive on the highway?

Fast.


drive my car with stock gearing and im at lie 3200 ~ 80mph, i also run an oil cooler though. no issues so far with several thousand miles on it. oil holds up nicely too.
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Post by schmauster920 »

Yeah if i cruise really fast i notice my oil temps go up pretty quickly, im guessing wind resistance\load on the motor, therefore the extra heat.

You would probably be fine if you dont track or drive your car really hard for extended periods (10+ minutes) You cant ever go wrong with an oil cooler on a turbo motor, and you dont want to find out the hard way.
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Post by beercandrifter »

especially since you can just find them in the junkyard if your lazy
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Post by AFKOUKI »

Sounds like im adding an oil cooler to my shopping list. I was really unsure if that would put my motor in boost holding it at that rpm for long periods of time. What is the optimal placement of the oil cooler, just put it in line with the turbo oil feed lines?
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Post by schmauster920 »

Most people get oil filter sandwich adapters, which gives you out/inlets for hoses. If you get one with a built in thermostat, (you should) it will work like the one for your coolant, regulating a certian temp (around 200-230) so your oil can boil off gas and water vapor through the PCV.

Steel braided and AN fittings are a good choice because it wont get worn through from rubbing and the last thing you want is an oil line rupturing or hose clamp coming off.

Maybe the best place for the cooler would be behind the radiator if you dont have a thermostat.
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Post by 8-bit »

Don't add an oil cooler unless you're doing constant track racing. Big waste of time and money.

The quick, and clean, answer you need is that there is nothing wrong with driving 80 mph on the freeway with a kat, even with a j30 diff.

Put it this way... there is relatively no difference between cruising the freeway on your NA motor or a boosted motor. The only difference you should notice is when you accelerate, you will make more power and heat.
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Post by AFKOUKI »

Thanks 8 bit, what i was essentially looking for. Is that the same with any size turbo? Doesnt a t25 boost around 2500rpm?
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Post by ppctx »

Weird, but boost is more of a punch it vs an rpm thing. You can ease on the throttle up to x rpm and not get into boost, or slam the throttle hit boost at the same rpm. Fun stuff.

I've never researched it but if there is a temp modulating oil cooler, go for it. Otherwise, oil needs to be at a certain opperating temp to work. Oil is heated by the engine. The engine is cooled by water. The water is cooled by the radiator.
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Post by 8-bit »

AFKOUKI wrote:Thanks 8 bit, what i was essentially looking for. Is that the same with any size turbo? Doesnt a t25 boost around 2500rpm?
It won't if you dont make it.... Cruising is just barely having the throttle open.
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Post by TryingToTurbo »

ppctx wrote:Weird, but boost is more of a punch it vs an rpm thing. You can ease on the throttle up to x rpm and not get into boost, or slam the throttle hit boost at the same rpm. Fun stuff.

I've never researched it but if there is a temp modulating oil cooler, go for it. Otherwise, oil needs to be at a certain opperating temp to work. Oil is heated by the engine. The engine is cooled by water. The water is cooled by the radiator.
You can buy a thermostat to control your oil temps. basically, you set it up so that the oil bypasses the cooler until this inline thermostat reaches a certain temp and then it opens, allowing oil to flow through the cooler as well.
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Post by Freise »

You will not be in constant boost even with a T25 on the highway, boost is dependent on throttle plate, not just rpm. So even at 3000rpm you will still be in vacuum. And when you step on it, instant boost.
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Post by R33E8 »

Is something wrong with my car? I am at like 4k rpm at around 80 mph with my bone stock 240... Maybe my tach is off.. it shows that I idle at like 1100 rpm when it sounds like it idles normal..
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Post by AFKOUKI »

once my car is warm my idle is ~750rpm. right under 1100 when its cold
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