engine prep for turbo

[DrivewayDrifter]

I own a 97 240sx with around 150k miles and I am planning to purchase the Greddy turbo kit. i want to keep the KA motor instead of going the SR route.

What kinds of things can i do to prep the engine for the turbo?

How much do these suggestions tend to cost?:help

[s13sr20chris]

you may want to ask the guys in the ka det/et forum about this. i would say that the engine hard parts are good for 10+ psi. that would mean you could make good power right off the bat on stock innards. i dont know whats in the greddy kit but you may wish to intall colder plugs(ngk only), oem wires, cap, and rotor, cat back exhaust, synthetic oil, new coolant, fuel filter, etc. all that maint type stuff should fall together for less than $200 plus like $400 for a nice apexi N1 catback. thats if you install it all yourself. as i said im not sure what kind of fuel management the greddy kit uses but an hks afr and nismo adj fuel pressure regulator could help with dyno tuning. hks afr is less than $300 i believe and nismo fpr is like $90. that should be a good start.

[hotshot240sx]

ok prepping the ka for turbo is expensive...like my fellow mechanic SRCHRIS says, it can handle from 8-10 psi with hard internals but the trick is getting it to boost further, and that lies in the block! YOU MAY BE ABLE TO HOLD UP TO 250-300HP. but its risky as we all know. so the best thing to do is lower your compression to 8.5. now you will need to up your fuel system. possibly to 550cc should help. ecu needs to be tuned as well as the head with the addittion of a metal head gasket from greddy or NIZZX. that will help lower the possibilty of blowing it. with the info from SRCHRIS and myself you should be pretty strong. but you must stay safe, or your motor will and i qoute "WILL" go to crap. you have to remember you have a pretty high compression ratio, so in order to achieve full potential your block must be built to handle boost... and as long as you dont boost heavy you should be OK!

[DrivewayDrifter]

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[slc240sxse]

I am thinking about doing the same thing. I am not sure if I am going to go the Greddy route, but I have some additional questions. My KA is coming up on 150k as well. It is an automatic.

In order to do this project correctly, from what you have stated, the compression ratio needs to be dropped from the stock 9:1 to a lower 8.5:1. Now, as you can understand, if you're going to end up pulling the block to do this, I can only assume that it would be in my best interest to rebuild the entire engine. Now, if you will bear with me, please suggest to me the following; I have a history of working on Mopar Muscle cars, and I have done extensive work on those engines. Some of my questions might be silly, but I am an import Noob.

1. What type of pistons / rings do you suggest.2. What type of connecting rods and bearings do you suggest.3. In my best interest to convert to a 5 speed yes or no.4. What type of cams / rockers / valves do you suggest.5. Are timing gears available for this engine.6. Should I replace my Cat Converter.7. With the new turbo, you mentioned the ecu needing a tune. Is this done by Jim Wolfe Tech.8. Do you suggest a VLSD for the rearend.9. Do I need to have any of the valves oversized.

I would like to push about 300+ HP out of this engine, so I would like to go tough on parts, and do it right from the start.

Thank you for your help.

[hotshot240sx]

well from my understanding as to what i have seen done... you can turbo it with out internals for a descent amount of power... all im saying is that if you want to stay "SAFE"... meaning more reliability...more power... with less risk... then building the block for turbo would be the "SMARTEST" thing to do... now you can hold up to 300hp MAX as to what ive seen and heard on stock internals. now is it safe. i doubt it. CHRIS made some good points earlier in the thread. my buddy is 9 grand into this project... and i will have to ask him how he went about with the twin cam. but he is well over 400hp. now thats a complete rebuild, alot of aluminum internals from what he says and a hell of alot of time. i am no professional when it comes to turbo apps. but he has done this many times over.

[s13sr20chris]

lets see for a ka24de in a 96 s14...300whp may be achievable on the stock bottom end but you dont mind building the motor so let do it. i cant really say much as to what brands of rod and piston to use. i do believe in this case you get what you pay for. stock rings are good but if you buy pistons, get what rings the piston folks rec. i would go 5 speed but the auto could be ok too. at 300whp a 5 speed conversion may be cheaper than a built auto trans. valvetrain- if you have the money get some jwt cams, springs+retainers, and adj sprockets. that aint cheap but i believe its prob the best route for a ka24de. with a turbo setup that may be a little too much duration. you could dial out some overlap with the sprockets. the stock valvetrain is prob fine. what matters on a ka is bottom end. its tough untill you try to rev high. built and boosted just stick to 7000 rpm redline(my guess). a high flow cat would be a good idea with a complete exhaust. apexi n1 is a good exhaust. its loud, cheap, and usually makes more power than any other on a turbo 240sx. the ecm needs tuned one way or another. if you dont want to do it yourself, a safe way to go is the jwt tune. just tell them what you got for power equipment plus what injectors and maf you are using. you will prob need a z23 maf and 550cc injectors for 300whp. yes, vlsd would be good. vlsd is cheap at the junkyards or you can drop $1000 on a fancy aftermarket lsd. the valves should be just fine for turbo applications. the only thing i can think that you may want is 1mm oversize exhaust valves and some good sodium filled or inconel valves. now that i think of it nico sponsor http://www.ka24de.com has some really nice valves. they are .5mm oversize and come nitrided or inconel. they also have other good stuff there.