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This is not really a simple job....until you find out that you can have a fun and high HP, high performance boosted engine WITHOUT making it hard OR expensive. First thing I highly reccomend, is do an engine rebuild AND break it in first. Tell your machinist you plan on adding a turbo and ask them to use the lower compression pistons. A turbo adds a lot of pressure, even at low boost. Lower compression will help daily drivability. Wheather you boost 6-8lbs or 25-30lbs. Another thing no one ever says is BE SURE and run a "one step" colder spark plug!! Gap it at .027-.030 to keep from blowing out the spark. A plug the book calls for will detonate and blow the engine the first time you boost it!! You'll read on the internet how there are those pushing 30lbs of boost and 500hp!! Well, God love 'em, THAT's where one spends a LOT of money on things like forged pistons, forged rods, a lot of "upgrades" to make it do that without blowing up. There are turbo kits out there that allows one to run up to 10 lbs of boost and still have a daily driveabled car that's just a blast to drive!! 10lbs of boost in a stock rebuilt KA24DE, which is the factory engine in the 240SX, will produce around 260whp. That "W" means at the wheels. So your producing over 300hp at the crank. A common problem is the piping from the turbo compressor to the intercooler then to the throttle body will slip apart under boost. A simple fix is while installing it, take a pair of pliers and gently "bell out" about 1/4" on each end of the pipes. Anywhere there's a coupler. This will keep the clamp from sliding off the end and creating what's called a "boost leak". A massive vacumme leak. You can also use small zip ties on the small factory vacumme lines to keep them from blowing off. A good boost/vacumme guage is a MUST to let you know what level the amount of pressure the spool up produces. Don't want to over boost. Use a blow-off valve but recirculate it back into the intake between the MAF and the turbo unit. It relieves the pressure when you lift the accererator. That pressure has to go somewhere. When recirculated, it keeps the air/fuel mix correct as metered by the MAF when the air was first drawn in putting the correct amount of air back in the system. Another thing few mention is you MUST use an oil pressure restrictor in the inlet feed line. This is a MUST as a turbo is usually set up for around 30psi oil pressure max. Any more and it'll blow out oil seals and leak oil. For example the dual cam KA24DE Nissan delivers aprox. 60psi oil pressure from the factory. Restrictors are available on EBay or just Google, "turbo inlet oil restrictor". You'll find one. The drive train on your factory 240SX will easily handle up to 400hp so don't worry about breaking the trans or rear end. Although a stage 4 pressure plate will be needed to keep the clutch from slipping. You'll be around 300lbft of torque onced turboed. One more upgrade I highly recommend is a 255lh fuel pump to keep up with the fuel pressure. About $100.00 and worth it even if you don't ever add a turbo. Plenty of fuel pressure saves one from detonating and burning pistons....boosted or not. Again, that's just my opinion. Take it or leave it. lol. The external wastegate is the secret to an "inexpensive but fun" kit. Look for a kit that includes a 6-8lb boost waste gate. This will save you from having to upgrade fuel injectors, ECU, Mass Airflow Sensor, ect. The ECU alone will cost anywhere from $300.00 to over $600.00. The MAF will be around $100.00, so you see what I mean. Above 10 lbs and those things will become nessasary. If that's what ya want go for it... but get ready to be working and tuning on a daily basis. Always tinkering to keep it running. Now the first thing is the kit. CX Racing has, IMO, the best one. It will come with every thing needed under the hood. Exhaust manifold, compressor, intercooler, piping, clamps, gaskets and couplers all in one order. Very convienant. No that's NOT a commercial. Check out EBay, Amazon, where ever you shop. One of these kits will cost as little as $650.00 to $900.00. The "name brands" will run up to $5,000.00!! That's crazy, if ya ask me. The T3 T4 hybrid turbo is, IMO, the best one to go with. It allows you to run the small boost smoothly but also allows you to go balistic with the higher boost if you decide to do so. Up to 35lbs. If you have any mechanical ability at all, you can do this install. It's not hard, and the reward of horse power is just awesome. Do your research, read all you can on forced induction. Read the 500hp guys with a grain of salt. You can do that later if you want, but I'd start small and build up, if I had it to do over. Hope this helps. Go after it. It's a GREAT father son/daughter project. YOU CAN DO THIS!!

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How can I increase the horsepower


A simple question with a not-so-simple answer. Engines are designed to last a long time "the way they are." Anythign you do to in crease hp will reduce the life of the engine.

That said, the punk way to get more hp is to add a nitrous kit. Nitous is nitorgen and oxygen. Nitrogen is an inert gas but it gets hot and takes away some heat out the exhaust. It is the oxygen in nitous oxide that helps the fuel burn more efficoiently,thus more hp. Your engine may not be able to pbhysically handle the increased torque without breaking. Aluminum pistons melt easily and nitrous in excess will do that to them. (Watch episodes of Street Outlaws" to see nitorus motors destroying themselves.)

Another way to achieve more hp is to install a supercharger and klimnit the boost to 6 psi on a stock motor. Beyond that, a "boosted" engine requires a lower compression ratio in order to handle all the increased amounts of air and fuel without destroying itself. Air-boosted engines require proportionally increased amounts of fuel to maintain "stoichiometric" air/fuel ratios. That means larger fuel injectors, a larger fuel pump, fuel pressure regulator, cooler spark plugs, and a computer to figure out what to do with it all.

Turbocharged engines have exhaust valve timing retarded by about 20 degrees to prevent "reversion." A larger exhaust sytem is required to exhaust the increases amount of "products of combustion" created by all that fuel and air. Then, too, adiabatic heating of the (now) compressed air requires cooling before entering the engine. Air molecules are farther apart when hot (less dense) so cooling the air delivers more O2 per unit volume, necessitating an intercooler for that purpose.

Hopped up turbo cars often run on E85. Alcohol has less energy so it won't take you as gas, but it burns MUCH cooler so you can crank up the boost! Guys are running 35-40 psi on the streets with E85 and making 700+ hp in some cases. But then, they have 10-25k invested and the engine is only some of that. Drive trains have to be strengthened.

Peformance engines are designed to handle the torque they make. Stock rods, cranks and pistons *may* hold together but beefed up aftermarket items are the way to go for increased reliability. A "stand alone" engine computer is required if you have any inclination of ruling the streets in your town or even being a contender.

There is, obvioulsy, a lot to know before you "add horsepower."
Visit a speed shop that has a dynomometer. They can advise you best. (They aren't serious if they don't have a dyno.) And don't listen to braggers online. They are not much help. The best way is to understand the physics of 4-cycle engines. After that, have at it and be prepared to spend a lot of money for parts and tickets! For me, the fun was in the learning!

Mar 03, 2015 | Cars & Trucks

2 Answers

i have a a 99 chevy silverado and it has lost h.p for some reson i can not find the problem please help.


It is really hard to say without all the information. Usually there is something simple that causes a loss of power. Is there any check engine light? If there is a check engine light then the ECU is causing the engine to derate. If there is not a check engine light then something simple like the fuel filter can sure cause the problem. The fuel system is a high pressure system and when the fuel filter gets slightly plugged it can cause a drastic horse power problem. The fuel filter is an inexpensive start until we have some more information about all the symptoms. Hope this helps you out.

Dec 31, 2010 | 1999 Chevrolet Silverado 1500

2 Answers

diy possible for installing clutch in 2007 mazda speed 6


You will need an engine support bar.
As far as performance clutches, most have more plate pressure and can be a bit rough on actuators (master and slave) . I've been known to cross-breed a performance disc with a stock cover, to take advantage of the better friction material without dramatically increasing pedal pressure. Most good performance clutches are built to be explosion resistant but unless you are prone to missing shifts or are running the engine above 7,000rpm, they aren't really necessary. In order to "mix and match" parts though you really need to know what you are doing or your best ideas will turn everything to trash.
If you intend to try this yourself, best thing you can do is at least get a decent manual to work from. Doing a clutch isn't like changing a spark plug. A mistake inside can cost you a lot in $ and time!

Jun 09, 2010 | 2007 Mazda Speed 6 Sedan

1 Answer

I do not have a problem but want some information can you encreast the boost on the 2008 Sportage.


increased the boost as performance wise? im assumed you have 4cyc with 140 hp, i dont recommend you try to modified 4 cyc or v6 173 hp, kia has 7/100k mile warranty on them, any modification you will void all warranty. you can increase HP or boost in any car is you know what you doing. you can keep it basic. Put new air K&N intake, will give you another 5-8 HP to the car, redo exhaulst systems will also will add another 8-10 HP; add new high performace coil will also give easy 2-5 HP. running high octain gas will also help for boosting HP. hope that help little

Jul 09, 2009 | 2002 Kia Sportage

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