Na6 weekend warrior Turbo build
 

Hi guys,

I have a 90 model Na6 which i use for weekend club days which I am just about to convert. Im a long time member rare poster here and want to know if ive missed anything.

Mods so far-
-Custom solid lifter cams, 260 deg exhaust 265 inlet, 9.8mm lift i think cant find specs atm
-Solid lifters
-Heavy port job
-Acl race series rings and bearings
-Acl pistons
-Shaved to 10.5:1
-BP flywheel with exedy 4 puck brass button clutch
-6 Speed
-Link v10 standalone ecu with all the sensors necessary
-Hole in firewall style pod filter inlet
-Extractors and 2.5" mandrel stainless straight through exhaust
-HKS Hipermaxx Circuit coilovers
-Whiteline sway bars
-Poly bushes all around
-Braided lines good pads
-Stripped, no stereo power steer air con carpet etc
-Underchassis bracing
etc etc

So far the things i have lined up for the conversion-
-S13 blacktop T25
-Stainless manifold 3/4 done, will have 3 inch dump pipe to my 2.5 exhaust
-R33 GTST intercooler (done know if you guys get skylines over there..?)
-Series 5 RX7 550cc injectors
-LC1 from diyautotune
-all necessary couplers and oil lines etc..

Im looking at possibly getting a copper head gasket to seal it and bring compression down, my goal is anything over 200 rwhp with lots of driveability.

Will i need to drop compression to make this power figure or not because Id like to keep the exact same driveability as now but with the added torque from the T25 in the upper revs?

Have I missed anything for this?

I am looking at getting a 1.8 torsen but i havent found a reasonably priced one yet.

Also what sort of boost pressure is safe on a stock 1.6, and can anyone huess how much boost im going to have to run through the T25 to hit my power goal?

Thankyou for your patience reading this, I hope i get MT.nets usual blunt but informative answers.

Dann

you can easily hit over 200rwhp safely with that set-up

Thankyou, what I'm concerned about is the limit of the turbo and the need to decompress. Any thoughts anyone?

Cheers,
Dann

What are ACL pistons and why all the motor work with stock rods?

I say sell the built block and turbocharge a stock 1.6, or scavenge your ported head and put it on a stock 1.6 block.

The black-top turbos are 2554s, right? (guessing) If so, you're going to be at just over 200whp maxed out, based on what people usually see with them.

Sell the built block?

Yeah, unless a 10.5:1-pistonned block with stock rods is good for turbocharging...

Sell it, enjoy the money it brings, turbocharge a stock 1.6 and make 200 hp.

Why not keep it, with all its balanced and polished/knife edged crank etc and decompress it with a thick copper gasket?

Also, if I buy just an NA8 diff and tailshaft can i use this with my na6 driveshafts (between my diff and hub)

Thanks,
Dann

Because its no better to you than a stock block. Might as well sell it and make a few bucks. Stock rods are good to ~250whp in a street car, and that wont be any different with your "built" block. Unless of course it has rods in it, and you failed to mention that.

Ok thankyou.
What power are m tuned rods good for? And stock pistons..
Thanks
Dann

mtuned rods and stock pistons will take you over 300 at the wheels if you go with a reasonable EMS (i.e. get rid of that fucking link).

Also, using a thick headgasket to lower your CR is a time tested but shitty idea. running that high of a static CR to begin with and then eliminating your quench area is just asking for detonation. 10.5:1 + small turbo + pump gas = trouble. Just do what everyone else here is calling for. Stock motor, smallish turbo, 200whp will do you just fine.

Not to mention that using a thick headgasket to lower compression kills quench.

If your goal is over 200 rwhp and good driveability, that's easy and doesn't require a built engine. Look at my sig - that's over 200 rwhp, great driveability and been turbo for about 4 years now.

No, you need the 1.8 drivetrain from the transmission back. Driveshaft, diff and housing, and axles.

I dunno, if you've already got the built engine, I'd say throw in the $300 rods and then turbo. Why not have the built block? Although the whole compression thing does need to be addressed. This is unless you desperately need money.

No its fine, I can either use my crank and new rings / bearings with a factory block and m tuned rods, or use a thicker copper head gasket.

Ok so now i have everything i need except the rods and gasket. Do the m tuned rods use stock sized bearings?

Thankyou for all the help,
Dann

Ok and one more question,

http://img29.imageshack.us/img29/8218/15092010054.jpg

Uploaded with ImageShack.us

The above driveshaft, this is a pic that a wrecker has sent me to suit my new 4.1 NA8 torsen. The torsen I have has got stub axles and a flange plate but these obviously dont. Is this a later model shaft ready to slide into the side of my diff?

Thankyou
Dann

That flange is the difference between the two and one piece axles. Obviously the one above is a one piece, and it sounds like you have the two piece axles. I want to say they are not interchangeable, unless you have the diff from the one piece setup as well. Don't quote me on this though.

Are you piecing together a 1.8 diff swap? Why can't you get the axles from the same place you're getting the diff.

i thought you could swap out axels! all you had to do was pull the intier 2 piece set up out and pop in the 1 piece axles. and the axles in the above pic are for ABS (correct me if im wrong!)

Yeah they have the abs rings on them. and I have since been told that the axles just slot into the box. I hope the abs sensor ring doesnt get in the road.

Im buying them from a wrecking yard and they have sold the rest. I got a bit fucked around with it.

UPDATE: I have a S13 T25 just rebuilt, waiting for M tuned to stock more rods, got my Lc1, series 8 injectors, tune cable and laptop, intercooler, and the rest of my diff conversion will come to my place by friday (getting couriered).

Cant wait,
Dann