I'm not new to turbo applications. I've built a 92 Talon TSI AWD top to bottom with much success. My problem is that I have no idea where to find more informaiton on boosting a 240. I know that most n/a cars need stronger bottom ends to support more power.

Bottom end:
-low compression pistons
-forged rods
-micropolished and knife edge crank

Questions:

-What's the stock compression ratio?
-Where can I find low compression pistons?
-Is there a common Nissan piston/rod combo?
-Any horror stories of playing with the crank?

Next, since I'm replacing my headgasket (copper head gasket replacement), I'm going to do headwork. I've got the hook up with a friend for machine work.

Headwork:
-7 angle valve job
-new seals
-self port and polished head, decked (I've done porting and polishing before, so no worries )
-polish intake manifold

Questions:
-Is there a larger stock throttle body? Would the stock one be sufficient?
-Should the MAF go on the intake side of the turbo, or between the intercooler and T.B. like the GM MAF. My guess is the second option.

On to the turbo.

-Should I get an aftermarket turbo manifold, etc, or will a stock turbo mani work ok?
-Where can I get one at?

That's all I can think of right now. I'm tired.........

Anything I should know before getting into this project? Anyone on these boards running boost on a previously n/a car?

Thanks guys!

 

-What's the stock compression ratio? if i remeber correctly it is 9:1 but could be 10:1

-Where can I find low compression pistons? jspec.com, aris

-Is there a common Nissan piston/rod combo? go to www.ka24de.com

-Any horror stories of playing with the crank? no one i really have heard plays with the crank too much.

-Is there a larger stock throttle body? Would the stock one be sufficient? there is a guy running 504rwhp with a stock one...so it should be good to go.

-Should the MAF go on the intake side of the turbo, or between the intercooler and T.B. like the GM MAF. My guess is the second option. 2nd option...actually let me look at some pics and see where they stick them.

-Should I get an aftermarket turbo manifold, etc, or will a stock turbo mani work ok? you have to get aftermarket. there are several that are log style but if you want an equal length then go to www.turboboss.com

-Where can I get one at? just search there is now a few places that have them now.

 

Thanks for the help. I'll be doing more research before continuing the project. I'm taking it into Nissan next week to have some diagnostics done to it.

If I have more questions or if you have any suggestions, please feel free to respond. Thanks!

 

Answers:

Bottem End:
- The stock compression ratio is 9.5:1... organic head gasket that will hold unless you detonate the engine, which is a good idea, as something has to give due to excess cylinder pressure.
- Low compression pistons, only if you plan on more than 330RWHP... talk to Marc @ import-autoperformance.com, he has a set in stock. Tell him Alan sent you.
- Common parts are with other KA24DE engines.... pistons are cast and the ring lands are very very thin... thats the weakest portion of the bottom end.
- Don't bother with the crank, it is forged steel... if you build it just have it balanced.... it's been proven to hold over 550rwhp.

Headgasket?... and headwork, only if you plan on making over 450RWHP. The KA head flows quite well and the head gasket is as tough and gives way under detonation quite easily to save your bottom end.

Headwork:
- Again ... unless you plan to make more than 450RWHP.... wasting money.... just get the appropriate set of cams.

General Questions:
- There are 500+ RWHP KA's so throttle body hasn't been much of a bottle neck.
- Blow through MAF.... Some MAFs read inaccurately if its on the pressurized side.... Dennis (Heavy Throttle) runs a blow through and 350 RWHP with no issues.... its a Z32 MAF not the stock KA..... which brings me to the question, if you are serious about building a monster KA? why do you want to use a MAF setup?

Turbo:
- Stock turbo manifold?.... ok are we still talking about the stock US 240 engine the KA24DE. You have a few options here, since you want all out power... Go with an equal length tubular manifold. import-autoperformance.com .... Its home grown MIG welded, but it is quite strong. I've had major brand name manifolds crack on me and this one looks quite strong.

Anything else you should know:
- Bring lots of money
- Plan on downtime
- Be patient and resonable
- Ignore the ricers and dime-a-dozen haters
- Work on this project because you love to do it
- Safely tune and don't forget to have metering equipment to monitor the engine parameters......

Here is a test fitment picture of my setup Take your time man.

 

thanks for the info........looks like you read my mind.

I know that on my talon I couldn't bypass the maf.....didn't know you could do it on this car. Explaination of doing so would be great!

I don't think I'm going for an all out powerhouse monster, but I'm just following some guidelines I feel you should follow when going from NA to FI. Since I'm new to this car, I just posted what I thought I would have to do to accomplish this sucessfully.

So, correct me if I'm wrong-

Stock bottom end is good enough for boost until about 330 whp.
Get a new headgasket cause mine is blown.
No head work is necessary because I dont look to push a lot of power (lets keep that 330 whp a good target hp for me to hit).
Cams are what I should focus on for now as far as bolt on's go.

So that's the engine work I should worry about? Damn that sounds like a plan. Piecing together the turbo kit is no biggie. Nuts and bolts.

Only thing I'll need help on is that MAF situation. I see you can use the 300zx MAF. A little more info on that if possible.

I know I'll have more questions later. Thanks for the help bro.

I'm on aim if you ever get on. My SN is the same as my board name.

 

Stock bottom end is quite strong for a 4 cylinder... just make sure you have the fuel system.

300ZX MAF, upgraded injectors (555cc) and JWT ECU is a common setup for 350 rwhp.

all other info there is the way to go. If you are serious, give the guys at import-autoperformance a call they sell a kit and can work things out with you. But like I said again, take your time before you make a decision..... goals goals goals....

 

when you move the mafs to between the tb and intercooler are you going to put the bov before or after that? ive heard of people puttin the mafs right before the tb and then purging to the atmosphere without the bogging. does this cause a problem for the sensor itself to be there though? this is the setup that im planning to run if its safe..

 

300zx maf plug and play?

 

What you are refering to is a "blow-through" MAF setup. The 300zx MAF requires an ECU tune that can remap its electical voltage scale, so no it is not "PNP".

As for the blow-through MAF, for some it has worked others it haven't due to turbulence.... I'd rather play it safe and recirculate the BOV.

 

Why not skip the MAF setup and go for a stand-a-lone unit? Don't go too crazy with the cams either, just a little something more performance oriented. Turboed cars don't like huge overlap. Well I'm sure you know, you had a TSi.

With the head, I don't think a fresh valve job would hurt, the 7 angle you mentioned seems overkill, just go with the standard 3 angle to freshen the ports up. That will help those nice new cams out a bit. The head of the KA flows fine in the low to mid-range area, but starts to choke up at higher RPM's, so the head could benefit from the valve job in that way also.

 

My sentiments exactly. I'm not a fan of untunable, hacked ROM solutions