Should I Go thru with it or no...??

[Thee 240sx Owner]

First i wanna explain that i will be posting this in both the NA Motor and Turbo KA forum... for this question is one of both topics...

I have an 89 240 Fastback... with 260k on the motor... (dash reads in Kilos ) its has a bunch of problems with the motor... IE. Cam is worn... Need new oil pump.. new tensioner for timing.. Timing is retarded 4 degrees (so was the guy who chained the guides).. needs new clutch.. transmission doesn't sound to good.. sounds like a bunch of rocks are rolling around in there.... but everything else on it is running in good condition.. now i don't wanna be like everyone and do the swap... with an SR (short for sorry 20) and i'm not much of a fan of the CA...(weedwacker motor) so i was wondering.. if i should do a rebuild with all forged internals... (cam (ka24e).. pistons...rockers.. springs...etc) and then turbo it... or should i just wait for the motor to die and find a DE motor and turbo it..??? mind you this car never came with AC from the Factory.. so HP is what i want... i believe this car is from canada being that the dash reads in Kilos and its rusted on the bottom of the frame.... and theres no AC... but i want to know what everyones input/opinions on this is.. doesn't matter what you say... i want to make sure i'll be doing the right thing... since there is alot of money at stake.... thanks alot everyone....

[PROJECTRB240SX]

DO A FORGED STROKER KIT WITH 8.5/1 OR 9.0/1 COMPRESSION, THEN CHANGE YOUR CAM TO HIGHER LIFT SHORTER DURATION, BUY A MASSIVE 280Z TURBO OIL PUMP(YOU'LL NEED IT), CHANGE YOUR FUEL PUMP AND FUEL INJECTORS, GET BOSCH PLATINUM +4 PLUGS, AND MSD IGNITION, DO A T06 TURBO KIT, AND GET AN ALUMINUM RADIATOR. THIS SHOULD PUT YOU NEAR THE 450RWHP RANGE AND YOUR TORQUE WOULD BE ALMOST MASSIVE. AFTER THAT YOU'LL HAVE TO FIND A WAY TO PUT THE POWER TO THE GROUND. WITHOUT THE TURBO YOU SHOULD PUSH 300-320RWHP.

[Thee 240sx Owner]

now i have the high compression motor... my motor was made in 88.. should i have to swap pistons or anything else or should i just have it bored and the whole port and polish deal...

[240SXedUp]

Wait for the blow and do a DE swap

[PROJECTRB240SX]

THE COMPRESSION IS ONLY 9.5/1 IN YOUR MOTOR, WITH A HEAD GASKET YOU COULD LOWER IT TO 8.5/1 IF YOU'D LIKE. IF YOU WANT TORQUE STAY WITH WHAT YOU GOT AND BUILD IT UP, IF YOU WANT ALITTLE MORE TOP-END BUY A DE AND BUILD IT UP. IN THE END THE SOHC GETS TORQUE AND THE DOHC GETS ALITTLE (VERY LITTLE) MORE TOP-END.

[Thee 240sx Owner]

Now see what i was wondering.. i know the DE have the extra 2 valves on the exhaust.. would that make a difference in the Turbo spooling up quicker.. i would think so since it would be flowing more exhaust.. but i mean... i've been reading articles all over like the one on 240sx.org the SOHC 89 that was turboed and ran 13.8 on street tires.. ?? any clues on to the difference with the E and the DE and trust me i searched...

[TrueSlide]

Your oil pump is fine. SOHC Turbos are just as competative as the DOHC. And you already have the SOHC, find another or just rebuild and turbo. Not to mention parts for a sohc = cheap. As for turbos a t4 should be adequate enough.

Racin that SOHC 89 you read about, they got it to run a 13.06 on street tires at only 10PSI, or so they claim.

[PROJECTRB240SX]

THEY ARE BOTH 2.4 LITERS SAME AMOUNT OF EXHAUST IF THE COMPRESSION IS THE SAME.

TWO EXHAUST PORTS = SLOWER MOVING EXHAUSTONE EXHAUST PORT = FASTER, CONTAINED EXHAUST = QUICKER MOVEMENT THROUGH THE TURBO = QUICKER SPOOL THOERETICALLY.

AND IF YOU STROKE IT YOU CAN GO WITH A BIGGER TURBINE BECAUSE YOU ARE MOVING MORE EXHAUST QUICKER.

[TrueSlide]

2 exhaust ports would cause exhaust to leave quicker. The one exhaust port helps the E with its TQ.

[PROJECTRB240SX]

YEAH BUT THE TWO PORTS MOVE SLOWER THAN THE ONE THUS THE LOSS OF TORQUE. THE FASTER THE EXHAUST MOVES THE QUICKER THE SPOOL TIME. TWO PORTS GIVE MORE ROOM TO MOVE. ONE PORT FORCES ALL THE EXHAUST TO COMPRESS AND BURST OUT OF THE PORT WITH HIGH ENERGY. ALTHOUGH IN THE END ITS UPTO YOU, THIS IS JUST WHAT I HAVE SEEN WITH MY PERSONAL EXPERIENCES.

[Thee 240sx Owner]

now if i did headers on my SOHC... would i loose that quick spool up time or would it help.. or if i kept it the same size or smaller.. should that help it flow faster... to help spool up quicker.... does spooling up even matter.. i mean if i want my torque in my low gears cuz thats where i get all my power from anyways.. but i know the motors peak HP is around 5k to 5500rpm...?

[PROJECTRB240SX]

OK THERE ARE NO HEADERS FOR A TURBO CAR, ITS DIFFERENT STYLE EXH. MANIFOLDS, PULSE-LESS EQUAL LENGTH HAS THE LEAST SPOOL TIME, MIXED LENGTH HAS BOOST SPIKE AND SOMETIMES ALOT OF BOOST CREEP. TURBO WOULD INCREASE YOUR TOP-END POWER SO YEAH RAISING YOUR POWER TO THE 4.5K-5.5K RPM RANGE. IF YOU STROKE THE ENGINE THAT'LL GIVE YOU ALOT OF DOWN LOW POWER AND KICK A** TOP-END. THE SMALLER THE PIPING THE MORE PRESSURE THE FASTER IT MOVES. ITS ALL IN THE KINETIC ENERGY, YOU WANT AS FAST MOVING EXHAUST AS POSSIBLE.

[PROJECTRB240SX]

REMEMBER THIS IS ALL THEORETICAL ITS NO ALWAYS THIS WAY IN EVERY SITUATION.

[Thee 240sx Owner]

sorry bout that mixup with the Headers deal.. i meant if i get one custom made.. any certain way i should have the exhaust piped...IE. cyl 1 and 4 together...?? 2 and 3??? that sort of thing?? lil clueless on that part

[PROJECTRB240SX]

OK, FOR THE EASIEST SURE SHOT METHOD GO EQUAL LENGTH. BECAUSE UNLESS YOU KNOW HOW FAST THE EXHAUST MOVES FROM EACH PORT ITS NOT WORTH THE POTENTIAL TURBO DAMAGE AND/OR POWER LOSS.

[89240sx]

caps!!! why?

[SingleCamSam]

Quote »YEAH BUT THE TWO PORTS MOVE SLOWER THAN THE ONE THUS THE LOSS OF TORQUE[/quote]

Two small exhaust ports will flow faster at virtually all rpm than one big one. Even thought the actual area of those two ports combined may be larger than the one big one. This is why both engines make peak torque at virtually the same rpm, and why the 4-valve DE makes more top end as well. Both engines are good though.

[jrc90240sx]

Want to save the trouble and buy my engine? already to go, just 2000 or so?

JE forged pistons 9:1forged rods3 angle vavle jobjwt camjwt ECUport/polishport matchedfully balenced and blue printed bottom endnew rockers/liftersoil pan already taped for trubo

As you dont want to do, i would like to swap to the SR. pretty sick of my KA. only problem it has is a tick in the head (witch i cant figure out). i know you wouldnt want to buy, and i really cant see selling, with how much i would loss, but i am just sick of the thing. it would be cheaper for 200-350 rwhp to swap to the SR. trust me i have been kicking myself for sometime.

[TomsMR2]

OK, FOR THE EASIEST SURE SHOT METHOD GO EQUAL LENGTH. BECAUSE UNLESS YOU KNOW HOW FAST THE EXHAUST MOVES FROM EACH PORT ITS NOT WORTH THE POTENTIAL TURBO DAMAGE AND/OR POWER LOSS.

equal length is the hardest most expensive way. unequal definately isnt damaging in the least bit.Quote » PULSE-LESS EQUAL LENGTH [/quote] people do equal length to give 4 steady pulses. its definately not pulseless. Quote » MIXED LENGTH HAS BOOST SPIKE AND SOMETIMES ALOT OF BOOST CREEP.[/quote] those are wastegate problems. nearly all oem turbo cars are unequal length.

equal length turbo manifolds are almost useless untill a certain power point. the power gains are extremely marginal with low psi setups. for most cases, its an unnecessary costly item.Quote » TURBO WOULD INCREASE YOUR TOP-END POWER[/quote] a proper sized turbo gives an obsurd amount of low end power. you could be fully spooled by 1500rpm pushing some serious torque. alot of factory turbo cars fall on their face past 5Krpm.Quote » IF YOU STROKE THE ENGINE THAT'LL GIVE YOU ALOT OF DOWN LOW POWER AND KICK A** TOP-END. [/quote] stroking increases overall output, but wont change your curve at all. thats all deteremined by cams/valvetrain.Quote » THE SMALLER THE PIPING THE MORE PRESSURE THE FASTER IT MOVES. [/quote] its all about volume and velocity. if you go too small, you lose volume. you definately dont want pressure!Quote »AND GET AN ALUMINUM RADIATOR.[/quote]i dont recall anyone having cooling problems with the stock rad.Quote »IN THE END THE SOHC GETS TORQUE AND THE DOHC GETS ALITTLE (VERY LITTLE) MORE TOP-END.[/quote]the dohc has just as much (or more?) torque as the sohc, and more hp. its a better engine.Quote »TWO EXHAUST PORTS = SLOWER MOVING EXHAUSTONE EXHAUST PORT = FASTER, CONTAINED EXHAUST = QUICKER MOVEMENT THROUGH THE TURBO = QUICKER SPOOL THOERETICALLY.[/quote]thats the exact opposite of what happens.

man, you gotta stop posting misinformation and magazine tuning tips. sit back and read, and learn. dont spread halfassed backwards information. someone might mistake you as actually knowing wtf you're talking about.

[TrueSlide]

LOL, nice MR2. Just one thing I have to disagree with you about.

the dohc has just as much (or more?) torque as the sohc, and more hp. its a better engine.

I think the SOHC when boosted can be just as good.

[TomsMR2]

I think the SOHC when boosted can be just as good.

lol me too. i think once boosted, the difference is marginal.. yet top honor goes to the dohc still. i think id like to turbo a sohc just for simplicity of design, and cheaper cost of the car/new engines.