Roadracing SR or KA-T reliability?

[Twinturbozs]

Looking for some info and intelligent discussion about which motor will be preferable for roadracing. From what i gather, the cost of a KA-T will be very similiar to the cost of an SR swap. Id like to run about 250rwhp reliably. So each is very achievable which each option. I plan on running approximately 5 events a year. The car will be driven to and from the events which are approximately 2-3 hours away. The car will also be a semi-dailiy driver so A/C and powersteering is a must.

So im guessing an SR is already buillt for boost which probably helps in durability, but what about cooling? Do SR have better cooling passages through the motor?
What about parts availability? how hard is it to find main seals, oil or water pumps. Parts that can possibly go bad under heavy throttle?


Please knowledgeble info would be great from guys who have actual experience with roadracing. Im not looking for a simple "SR" or "KA-T" answer. Thanks

[OJmobileII]

Think about this, you can buy a K motor for a couple hundred bucks if the other one blows up. There cheap and very easy to find, were is if the SR blows up its going to cost more money.

When it comes to road racing you always want a tight budget or things start adding up all over. Id say turbo the K and then get a extra motor for the side. Cant go wrong with that.............

[Nan Desu Ka?!]

i can smell another KA vs SR thread coming... please, just search for both motors seperatly and compare what they have that is favorable to your situation. Make the decision and let us know how it goes. This thread is going to turn into a flame war.

[wootwoot]

I would personally want to start with a completly fresh motor built to the task of racing. I would rather have the low grunt and tq of a KA over the SR and this means the money saved from purchasing the SR could be put into completly building the KA.

p.s.
I would port out the coolant passages in either motor just to insure proper flow, stock casting leaves a lot to be desired. The best thing to do would be to find out which cylinder generally receives the least amount of flow and make its coolant passages the largest.

Either way you should do full suspension and good tires on the car, leave the motor stock. While you are learning how to drive it properly build the other motor but this will put you in the right direction and it will have to get done eventually anyway.

[ceniack]

Think about this, you can buy a K motor for a couple hundred bucks if the other one blows up. There cheap and very easy to find, were is if the SR blows up its going to cost more money.

When it comes to road racing you always want a tight budget or things start adding up all over. Id say turbo the K and then get a extra motor for the side. Cant go wrong with that.............

I would personally want to start with a completly fresh motor built to the task of racing. I would rather have the low grunt and tq of a KA over the SR and this means the money saved from purchasing the SR could be put into completly building the KA.


these two guys both make very good points. couldn't have said it better myself.

[Mr_Nice_Guy]

Look up the posts from '97 S14 SE Turbo on freshalloy.com. He ran a KA-T for like 4 years in track events before it gave up the ghost. Would be a good place to start looking for some information.

Hell here is a link for ya:
http://forums.freshalloy.com/ubbthreads/showflat.php?Cat=&Board=UBB9&Number=68037980&page=2&view=collapsed&sb=5&o=&fpart=1

[g6civcx]

You may want to consider taking one or two track days with the stock NA motor and see how it feels before turbocharging it.

[Tenchuu]

You may want to consider taking one or two track days with the stock NA motor and see how it feels before turbocharging it.
not sure why he would want to take the NA lack of kick motor out there othern than to make a baseline to compare his furure motor to.

but i am goign to go with the practical answer. roadracing = high abuse. KA-T

if you have a friend that can junkyard scavage a KAT from parts go with that, if you are like the rest of us and can't list off all the parts you wil need and source vehicles in the next 20 seconds than be prepared to spend just as mutch or more on a KA-T setup (to do it righ eithr piece togather a turbo, or get a decent one that is not the 5psi, 15HP greddy kit that they sell. talk about a joke)

done right the KA-T will end up runing as mutch or more than a SR, but that is going to be a nice fresh KAT vs a questionable quality SR. and like they said before when you DO brake stuff, cause you will, it will be easy source parts to replace.

[Twinturbozs]

Ive been roadracing for the last 8 years. Ive ran my S14 w/KA for the last 2. Id like to add approximately 100-120rwhp either by kA-T or SR. Obviously building a motor is the correct choice, but as with 99% of the roadracers here, budget is definitely a huge factor. What im trying to decipher, is it worth spending $6k on a KA-T with necessary peripherals or $6k on an SR with the necessary components.


From what i gather, a KA-T will give more grunt down low but less flexibility with the rpm range compared to an equally powerful SR? Im looking for longevity in a motor, im not in the business of swapping blown KA-T motors, but im also questioning the availability of parts for the SR in case things are needed.

[wootwoot]

if you want longevity you can always follow a similar philosophy to what the Corvette racing teams do, up the displacement and keep the revs down. High revs are ultimately destructive to a motor, and you dont necessarily need them if you are going turbocharged or even better have more displacement to keep your power band low. With a gt28r/s14 t28/ s15 t28 on a ka, you could have full boost from as low as 3300rpms(estimating high) pulling all the way to the redline with appropriate cams. If built properly I see them both being equally as reliable but ultimately the SR costing more because of its initial cost.

[DJPimpFlex]

well I run an SR, but you cant seem to beat the initial cost demons of the motor. Also now a days its harder and harder to find a good condition SR. It is a wonderful motor, and either would be a good choice. I wish I had driven both before deciding. I've driven 2 SR cars and no KA-T's. I dont think I'll ever switch back to the KA though . . . .

[g6civcx]

Ive been roadracing for the last 8 years. Ive ran my S14 w/KA for the last 2. Id like to add approximately 100-120rwhp either by kA-T or SR. Obviously building a motor is the correct choice, but as with 99% of the roadracers here, budget is definitely a huge factor. What im trying to decipher, is it worth spending $6k on a KA-T with necessary peripherals or $6k on an SR with the necessary components.


From what i gather, a KA-T will give more grunt down low but less flexibility with the rpm range compared to an equally powerful SR? Im looking for longevity in a motor, im not in the business of swapping blown KA-T motors, but im also questioning the availability of parts for the SR in case things are needed.

Ah, I see where you're coming from now. What kind of roadracing do you do?

I think for the money, the SR is a better way to go due to the amount of support you can get for it. There is some support for KA-T, but it's much easier to get stuff for an SR.

If you have $6K to build a motor, you should have room to spare to build an SR that will live on the roadcourse. The SR is so common nowadays that you can get parts for it from the dealer. I was a little skeptical of it as well, but I found tons of places that stock SR parts so it's not a big deal. Plus Nissan is slowly phasing out KA parts so soon you won't be able to get any KA parts from the dealer.

A lot of guys run the KA-T because it's a simpler setup than the SR, but I choose the SR because it has more support. I was hard-pressed to find shops that work on the KA.

[g6civcx]

not sure why he would want to take the NA lack of kick motor out there othern than to make a baseline to compare his furure motor to.

The reason I said that is because for the new driver with no roadracing experience, it's not about power. Power will get them into more trouble. He seems to have a lot of experience so it's a moot point.

For a new driver, an NA motor with low power is better to help them learn the basics instead of worrying about abrupt throttle response and power delivery. Low power will keep straightaway speeds down and keep braking easy to manage.

I learned on sub-100 whp cars. I think some people need to learn the basics instead of jumping on the latest race car, like a guy with practically no experience claiming that an Evo is a better track car than an S13.

Cheers! :naughtyd:

[drift freaq]

Ive been roadracing for the last 8 years. Ive ran my S14 w/KA for the last 2. Id like to add approximately 100-120rwhp either by kA-T or SR. Obviously building a motor is the correct choice, but as with 99% of the roadracers here, budget is definitely a huge factor. What im trying to decipher, is it worth spending $6k on a KA-T with necessary peripherals or $6k on an SR with the necessary components.


From what i gather, a KA-T will give more grunt down low but less flexibility with the rpm range compared to an equally powerful SR? Im looking for longevity in a motor, im not in the business of swapping blown KA-T motors, but im also questioning the availability of parts for the SR in case things are needed.
SR's make great road course engines. Due to the fact they rev very freely and live in the mid range and top end which lends itself to road courses really well. Granted Corvette drivers usually utilize high torque low revving engines. Though for the most part, as you probably know from your road racing experience, mid range and top end is important and a lot of fastest track cars out there are mid range to top end engine cars. The Corvette being one of the exceptions. Even a lot of the V8's in road race cars are living in the higher end of their rev band. Look no further than the Ford Cosworth engine which was a mainstay in Formula one for a long time as well as Indy/Champ cars. That was not a low revving V8. Now parts availability in the U.S. these days for SR's is extremely strong. Drifters are rebuilding their SR's on a regular basis these days to start with a fresh engine rather than a unknown.
Pistons, rings, bearings, gaskets, cams they are all readily available from several sources.
That said in the end its up to you to decide on the engine you like the best. I don't want to be seen here as saying the SR is better. I am just stating that it fits the bill well. The KA could be made to perform as well though out of the box is not quite as prepared. I.E. you can make it rev better and make it live in the mid to top end, but I feel it would take work to get there and the SR is there already.

[i8yourfwd]

i can smell another KA vs SR thread coming... please, just search for both motors seperatly and compare what they have that is favorable to your situation. Make the decision and let us know how it goes. This thread is going to turn into a flame war.
For once it didn't turn into a flame war. This is actually a really good thread.

[Nan Desu Ka?!]

Damn, your right. woot. I love Zilvia. Hopefully this thread will come up a lot in noob searches. way to go guys :thumbsup:

[Twinturbozs]

One last question which i couldnt find a definitive answer. Is a KA-T w/turbo and FMIC heavier than an SR w/turbo and FMIC? If so, what is the approximate weight difference, not including the relocated battery?

[sideview_180sx]

for road racing. simply put as long as you have proper cooling to the engine, and the internals of the engine are kept in check. regardless of what engine you use, heat will be your enemy regardless. I know this from my friends H4 CRX taking 3rd in points, not too mention 3 other SE-R and honda challenge cars we maintain and fix at the shop. Heat and cooling is what you should care about over power. More power= more heat. As a previous person spoke about cooling passages being enlarged to help with cooling. BTW koyo would not be the better choice. C&R and Griffin will be much better then koyo, in terms of racing. Look into a thermostatic oil sandwich adapter, to run in conjunction with the oil cooler you will need.

[wootwoot]

KAT will weigh more then a SR. Ever think about just putting a qr25 in there and running naturally aspirated?.... Probably breach your budget. Its just a dream I have that I want to see somebody try and pull off.

[Cashizslick]

Damn, your right. woot. I love Zilvia. Hopefully this thread will come up a lot in noob searches. way to go guys :thumbsup:


:werd: I found this thread really interesting because i am looking to get into road racing with my S14. There is a lot of good info in here.

[DJPimpFlex]

correct me if I'm wrong, but I read somewhere a while ago that a fully dressed SR with sidemount intercooler, alternartor turbo ect weights 9lbs less than a stock NA KADE. Forgot where I read that, but it was a deciding point for me.

[big-byrd]

another good option is looking into the ca18det. i'm not going to get into details since that's your job to find out. just throwing one out there for you to look into. good luck with your search and let us know how it goes.

[TheSquidd]

Wow... one of the best threads on Zilvia in a long while ^_^



I too decided to run SR20 for road racing. I'll let you know how that goes.


PS. Definitely run a few track days with stock KA24DE, or even SE.

A. You wont be so prone to kill yourself or wreck the car.
B. Low horsepower tends not to break the engine.
C. You learn how to properly utilize every bit of horsepower available when it is limited, thus, when you add more power, you'll be at a level where it actually benefits you in more than just the straightaways.

[jmauld]

Looking for some info and intelligent discussion about which motor will be preferable for roadracing.


Another thing to consider are the classes that you can run with each engine. I believe there is only one class that allows you to compete with the SR? While there are a couple of classes where you could compete with a KA. That is, if you are concerned with competing with the car eventually. The 240sx can be a strong player in ITA.

[TurDz]

Wow... one of the best threads on Zilvia in a long while ^_^



I too decided to run SR20 for road racing. I'll let you know how that goes.


PS. Definitely run a few track days with stock KA24DE, or even SE.

A. You wont be so prone to kill yourself or wreck the car.
B. Low horsepower tends not to break the engine.
C. You learn how to properly utilize every bit of horsepower available when it is limited, thus, when you add more power, you'll be at a level where it actually benefits you in more than just the straightaways.


you say it's one of the best threads, but you failed to read a significant portion of this thread by the original poster...haha

for your P.S.


Ive been roadracing for the last 8 years. Ive ran my S14 w/KA for the last 2.

[TheSquidd]

lol I actually did read that, I was just commenting on the SR vs. KA for road racing. Sorry, it was not actually directed at the original poster.


I just wanted to participate and feel smart like everyone else~! :confused:

[infinitexsound]

ka24de... great engine... suspension and alignments and tire choices are more benefical .. but thats just me...

[SochBAT]

http://img.photobucket.com/albums/v189/soshit/sochbat.jpg
OMG, GOH ZIYA!!!!

And NO, i will not get off my SOHC powered dreams!

GOOOOOOO REBELLO!

[i8yourfwd]

^^^ LMAO!!!!!!!!!!! omfg that was hilarious.. i almost choked and died.

[ladiesman8527]

well, you can do what im gonna do. im gonna swap in my sr when it gets warmer outside. but, im also gonna build up my ka slowly on the side for a backup. but as for your question. if both the ka and sr are built up right without taking any shortcuts, both should last a very long time.

[SpeedMonkeyInc]

Drift Freaq put it best: Go with the engine you like. Lots of people saying how nice it is to have that power down low. Sure, on the street. The only time you are at lower revs on a road course is when you screw up and end up in the wrong gear.
Who is this guy saying you can get more support for the SR? There will be no lack of factory parts for the KA for a long time to come. Same with the SR. Nice thing about the SR is so many well made parts ready to just bolt on. True for the KA as well, but fewer options. The KA is more of a DIY engine.
Like Sideview said road racing any turbo motor is all about heat management. Protect your BMC, heat wrap anything flammable near the turbo/downpipe/manifold, make sure your coolent system is good, add some water wetter, consider an oil cooler.

Personally: I chose the KA-T. Havn't been to the track yet, but I expect everything to be fine. I am interested in how long the engine will hold up.

[turtl631]

You won't necessarily be revving high all the time on a road course. If your powerband is low and your car is geared correctly, there's no need to keep the revs high.

[SpeedMonkeyInc]

Sure, if you have a huge V8. But we are not talking about big slow revving toruqe monster engines, we are talking about KAs and SRs on a road course.....and we are definatly NOT talking about custom gearboxes to get to whatever you consider "geared correctly"

[wootwoot]

ug. The redline of a ka would not be needed to be raised much above stock...With a t28 you would have a full 4000rpms of power, same as the sr can easily have but slightly lower in the revs. Changing the final drive will get you geared correctly. Neither motor will have "low" end but the KA will have considerably more mid range then the sr.

[574-240sx]

If you go KA-T it would be wise to invest in a upgraded oil pump, dual pass radiator and oil cooler. I believe a decent built one will last a while. Hell I beat the crap out of my KA-T and it still comes back for more.

[XxJaPxOxNeEs23xX]

but for road racing i prefer lower torque so less chances of messing up around the turns but still having power at the end, so i like sr better, even tho i dont have sr. i wish i did.

[BigVinnie]

I don't like these KA VS. SR threads at all, just starts to much biased opinion.
It's really upto you (the thread starter).
Both engine's would run good on a low boost.
KA has the potential to make power earlier in the power band while the SR drags power out, (which is good if your into higher top speeds).
Both are wonderful engines to work with each with there own attributes to suit how the driver enjoys his/her driving style.
I find this is more a topic where you should explore this question your self since it will be that you are the driver of your car. With enough R&D you should find what you like. I don't think anyone could answer the question that you left us with.

[infinitexsound]

word... what he said^

[wootwoot]

I have an SR =)

[EchoOfSilence]

The stock oil pan on a KA can't handle G's found in some/most hard corners. The SR's on the other hand, has withstanded it somehow

[infinitexsound]

sr are more oil starvated motors from what i was told by ppl who have em...

i like both, i just prefer my KA

[kuramaya]

Me and all of my friends rev the piss out of our SR's and they take it like champs....I think it is a very reliabe motor as long it is maintained...They dont blow often at all...shit the tranny's go before that will happen...as long as you maintain it, keep the right afr and control temp you should be good...here I can get a redtop SR for 500 Bucks usually so it is easier to swap if I needed...the only guys I know that have blown their SR's were putting down mid 400's
late
daryl