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1g 2.0L DSM Non-Turbo to Turbo Conversion


There seems to be two (or more) versions of this page floating around on the web, this is the original, and correct one. This is the only one that I update. If you have any links to other versions of this page, relink to this one. Thanks.

Warning: Do this mod at your own risk. If you have little or no experience working on cars, forget about this swap.

Anyway.. this is how I performed the conversion on my car. (a 93' chassis with a 6-bolt engine, a 90' 5spd n/t transmission, and federal emissions system). This swap doesnt apply to 1995 and newer cars.

Previous mods on my car that affected this project...


Ok, now.. down to the project.

First thing you want to do, before you buy any parts or even get your hopes up, is go over your car.

Do a compression and leakdown test, to make sure your engine is in acceptable condition to handle the extra stress. If your car has ANY problems right now, fix them before you start. If your engine is worn out or has a serious internal problem, then buy a used turbo engine and put that in, or sell the car and buy a turbo car.

If your engine is ok, move on to the transmission. I'm only covering the manual transmission here, I have never owned an automatic DSM, and I dont have much intrest in automatic transmissions in general.

If you do have a 5 speed, make sure you refill it with good fluid. BG Syncroshift, Royal Purple Syncromax are both excellent. I don't reccomend AC delco or Pennzoil Syncromesh anymore, they dont protect well enough under abuse. Also check your axles and make sure they're in good shape. Yank out your n/t clutch and recycle it. Put in an upgraded NT clutch (make sure it's made for the NT, the turbo dsm clutches aren't the same size and don't fit at all). ACT makes a Heavy Duty and an Extreme pressure plate, and a SS performance street disc, 6 puck race disc, and 4 puck race disc.

I reccommend the Extreme pressure plate with the SS performance street disc (ACT kit #MB3-XTSS), it holds 323 ft/lbs of torque. I have personally used the Extreme/6puck (ACT kit #MB3-XTR6) combo in my car, it holds 414 ft/lbs, it is very durable, and fairly streetable, but you are better off with the street disc. though. Don't try putting in a clutch that's made for a turbo dsm, they dont fit with the NT transmission. You would have to swap the transmission, flywheel, and clutch, and that's a waste of money and time. All you need to do is upgrade the NT clutch.

Most people will argue that you should replace the n/t transmission with the one from the turbo car because it's not strong enough. I don't agree. There's no proof that the turbo transmission is any stronger than the n/t. My transmission holds up just fine, and I really abuse it sometimes. The n/t has a lighter clutch and flywheel, and shorter gear ratios also. The n/t differential is identical to the one in the turbo transmission, so all the LSDs that fit the turbo cars will also fit the n/t.

I might aswell cover the issue of the oil jets now too. Some people say that turbocharging the n/t engine is not a good idea cause it has no oil jets (they squirt oil at the bottom of the pistons to cool them). You don't need oil jets. Oil jets work, and are a good idea, but they do have downsides. Mainly, they use oil that could be better used to supply the turbo and the other areas of the engine. This is especially true on our engines, that barely have any oil pressure at idle. There are better ways to cool the pistons anyway (water/methanol injection).

Ok, now get the parts.

You're gonna need about $300-$1500 for this step (depending where you live and shop). The first places to try are auto-recyclers and u-pull-it salvage yards. The prices there are usually alot cheaper than other sources. Other sources are http://www.dsmtrader.com/, http://www.ebaymotors.com/, and other parts traders or auction sites. Buying a wrecked turbo car is also a good option... one with a rear end collision or something. A target price for all your parts should be under $1000. I got mine for $600 total.

Take note, the 1g MT and 1g AT used different fuel systems and ECU's. The MT turbo used 450cc fuel injectors and a 36 psi pressure regulator, the AT turbo was different (390cc injectors, regulator was 43psi). I'm using MT turbo parts here because they're the better of the two. You have to match the injectors, ecu, and FPR, or the car wont run right. Don't try to mix and match (there's an exception though, I'll cover it later in the article). Also, california ECU's had an extra solenoid for the EGR valve, I dont cover that here, I'm using a Federal Emissions ECU. 1990 model year cars also had different ECU wiring, but there are other sites that cover that, so stay away from 1990 ECU's for this swap (unless you own a 1990).

Here's the parts list.

  1. Exhaust Manifold (1g MT, 2g, EvoIII)
  2. Turbo (14b from a 1G MT, 16g)
  3. 02 sensor housing (1g MT, 2g, EvoIII)
  4. 02 sensor from a turbo car (it has a longer wire, to reach the new sensor location, you don't need it if your wire already will reach, or if you rewire it yourself)
  5. Turbo Fuel Pressure Regulator (1g MT, 36 psi base pressure)
  6. 450cc turbo fuel injectors
  7. Turbo fuel pump, or upgrade pump for turbo car
  8. Resistor pack for 450cc injectors
  9. MT federal turbo ecu matched to the year range of your car(1990 is different from the 91-94 cars)
  10. Wastegate actuator
  11. Aftermarket boost gauge
  12. new fuel injector o-rings
  13. new exhaust gaskets
  14. 1g Turbo throttle body
  15. Throttle body elbow (1g or 2g, 2g is better)
  16. Metal check valve for the purge canister line (plastic ones blow out)
  17. UIC pipes and bov
  18. Turbo intake tube w/ bov return hose (dont vent the BOV)
  19. Turbo MAF and pigtail for wiring harness
  20. 16ga wire (a few Different colors)
  21. wire loom, solder, electrical tape, heat shrink
  22. electric fuel pressure solenoid and pigtail
  23. knock sensor and pigtail
  24. 1g sidemount intercooler
  25. lower i/c pipe, hose, J-pipe and turbo outlet gasket
  26. turbo aircan
  27. Throttle body and elbow gaskets
  28. Downpipe
  29. Turbo Oil Pan
  30. Oil drainback tube
  31. 5 feet of 3/8" coolant hose (hydraulic hose also works, dont use fuel hose)
  32. Turbo oil feed line w/ banjo bolts
  33. Turbo coolant hard lines
  34. High Temp Silicone sealer
  35. 3 extra (harness side) ecu pins, get from some used ECU plugs on junk car
  36. bolts for the turbo-to-exhaust manifold connection and the one nut (I used normal hardware store stuff, but you might want to get the correct bolts from the dealer)
  37. copper gaskets for the lines
  38. a whole pile of various vaccume tube, connectors, hose clamps, and an assortment of bolts and nuts(you can never have too much of this stuff, just incase)
  39. antifreeze
  40. oil filter
  41. oil
  42. premuim gas (dont try running that 87 that's in there now...)
  43. New spark plugs gapped at .028"
  44. Upgraded clutch
  45. transmission fluid


Now that you have all your parts cleaned, ready to go on the car, you can start to rip things apart.

Abbreviation Key:
TB = Throttle Body
IM = Intake Manifold
WG = Wastegate
TPS= Throttle Position Sensor
ISC= Idle Speed Controller
MAF= Mass Air Flow Sensor
ECU= Engine Control Unit
BOV= Blow Off Valve
IC = Intercooler
UICP= Upper Intercooler pipe
LICP= duh..
FPR = Fuel Pressure Regulator

  1. Jack the front of the car up far enough that you can work under it and over it comfortably. Use jackstands! Also make sure you have it in a spot where it can stay for a few days, just incase. Pop the hood and disconnect the negative terminal of the battery.
  2. Drain the coolant.
  3. Remove the whole aircan/MAF/intake tube assembly.
  4. On the throttle body, remove the coolant hoses, vac hoses, disconnect the throttle cable, unplug the ISC, the closed throttle switch, and the TPS. Remove the nuts/bolts (4 total) holding the throttle body to the IM. Remove the lower nut holding on the cam sensor and slide the IM brace off. Pull the TB off and transfer any needed sensors over to the turbo TB.
  5. Install the turbo TB and TB elbow in the reverse order of removal, dont forget the IM brace and new gaskets.
  6. Unplug the oxygen sensor and remove it.
  7. Remove the exhaust manifold heat shields.
  8. Get under the car and remove the NT downpipe.
  9. Remove the 14mm bolt that holds the power steering pump in place. Remove the PS pump heat shield. This allows you to access the last nut on the exhaust manifold.
  10. Remove the exhaust manifold.
  11. Place a rag over the banjo fitting on the end of the fuel filter and loosen it to relieve the fuel pressure. Be careful.. there may still pressurized fuel in system even if the car has been sitting.
  12. Remove the two hoses from the FPR. Unbolt it and remove it from the fuel rail.
  13. Install the turbo FPR onto the fuel rail, using a new fuel safe O-ring is a good idea to prevent leaks.
  14. Take out the three 12mm bolts holding the fuel rail in place. Tip: hook the metal tab on the throttle cable onto the window washer hose on the hood.. it'll keep it out of the way.
  15. Pull the fuel rail upward, and pull the 4 injectors out and set them aside.
  16. Pull the 4 manifold dust seals out and replace them.
  17. Put the new o-rings on the turbo injectors and slide them into place, and bolt the fuel rail down. You may need to put some motor oil on the o-rings to get them to slide into the fuel rail without tearing. They should go together smoothly, if you have to force them something is wrong.
  18. Tighten the banjo bolt on the fuel filter and connect the hoses back onto the FPR.
  19. Take a break now and let the gas fumes dissipate.
  20. Get inside the car with a phillips screwdriver and a 12mm socket and ratchet.
  21. Pop the caps off the side panels of the center console, and take out the screws. Set the panels on the side.
  22. Unplug the ECU (three yellow plugs). Take out the three bolts holding it in place and lift it up to unhook it, and pull it out on the passenger side. Set it in a safe place, you can ebay it for about $50.
  23. Bolt your new turbo ECU in. Don't plug it in yet.
  24. Get out your spools of wire and soldering equipment.Click here to go to webpage about the ECU pin locations for info on which pins get wired to what.. You will need to run one new wire from the ECU to the MAF sensor area under the hood. You will also need to run wires out to the Knock sensor(the red wire on the sensor gets wired to the ecu, and the black wire goes to ground), FPR solenoid (the red wire goes to the ECU, the black wire goes to ground). You can also wire in the Boost Control Solenoid (completely optional) and if you are using a california emissions ECU, the EGR solenoid will need to be wired in. They use the same basic wiring schematic as the FPR solenoid. Keep in mind, the 1990 cars use a different wiring diagram for the ECU than the 91-94 model years. Look at that ECU wiring website for all the info about that.
  25. In the front of the ECU plugs pull out the black center piece that locks the pins into the plug. This will allow you to insert the new ECU pins into the back of the plug. After you make all your connections and all your pins are installed, you can put this black piece back in, and plug the ECU connectors back into the ECU.
  26. Reinstall the interior panels.
  27. Bolt the FPR solenoid assembly to the firewall and plug it in. Unplug the hose that goes to the side of the FPR and connect it to the FPR solenoid. Connect the other nipple on the FPR solenoid to the FPR itself with a piece of vac hose. You may want to use some zip ties on the nipples to keep the hoses from popping off under boost. Bolt the injector resistor pack to the firewall or shock tower, in a secure place.
  28. Now to wire in the injector resistor pack. Take the 3 bolts out holding down the wiring harness onto the intake manifold. Pull the plastic cover apart and find the injector wires. There are two wires going to each injector. Each injector has a thicker and a thinner wire going into it. Ignore the thinner wires, we don't have to touch those. Cut the four thicker wires about 2 inches away from the injector plugs. On the wiring harness side of the wires you just cut, solder them all to the white wire going into the injector resistor pack. Heat shrink it or tape it up. Solder the injector side of those four wires you cut to the 4 black wires coming out of the injector resistor pack. Heat shrink or tape that up, and reinstall the wiring covers, and put wire loom over the wires going to the resistor pack.
  29. Now on to the MAF plug. The n/t uses a different MAF plug than the turbo cars do. Cut the NT plug off of the wiring harness about an inch from the plug. The wires are all color coded, and all of the turbo MAF plug wires will match up to the NT wiring harness, except for one wire that will have no match. That wire gets soldered to the wire you ran earlier from the ECU to the MAF. Heat shrink these wires, they have to be waterproof. Also make sure you get a good solder joint on these connections, or your ECU could get false readings from the MAF, causing all kinds of problems.
  30. Get in the car and turn the key on to ACC to unlock the steering wheel and crank the steering wheel all the way to the drivers side, so the tire is out of the way while you put the intercooler in.
  31. Unbolt the front inner fender liner on the pass side and set it on the side. Then unbolt the black resonator box (looks like a deformed milk jug). Take the box and the elbow that was attached to the top and throw it off a cliff.
  32. Now would be a good time to modify the fender liner. Alot of people cut out the louvers and put mesh there instead for better airflow. Don't do that if you live where it snows though... or if you drive through mud alot. I've found that drilling ALOT of 3/8" holes all over the louvers works as good as mesh, but still keeps most mud and snow out.
  33. Get some rubbing alcohol and clean your intercooler. Just dump half the bottle in and shake it around for a while. Do it a few times with fresh alcohol. Acetone works better but is very dangerous to work with.
  34. Now bolt the IC in place.
  35. Bolt your front inner fender liner back in.
  36. Install your UICP and bolt the BOV onto the pipe (seal it with an OEM gasket, silicone sealer tends to block the little pinhole in the BOV that's right next to the gasket area)
  37. Drain the engine oil and put the new filter on.
  38. Drop the transmission and change the clutch. Use a service manual for better instructions on how to do that.
  39. While the tranny is out you can get to the oil pan easily, so take your NT oil pan off and put the turbo one on, sealing it with silicone sealer. Make sure you put the short bolt in the correct spot under the timing belt crank pulley. If you dont, a longer bolt will rub a groove in your timing belt and the belt WILL fail. This is VERY bad, incase you didn't know.
  40. Remember to tighten the oil drain plug to spec. (29-34 ft-lb)
  41. Get your turbo manifold and bolt it in place, using a new gasket. Be sure you torque the bolts from the center outward, first to half the torque spec, then to full torque. This way you won't crack or warp the manifold and you'll be sure to get a good seal.
  42. Reinstall the bolt and heat shield you removed from the PS pump earlier.
  43. Get a rag for this step. Take out the plug on the end of the oil galley on the clylinder head. It's on the side of the head in front of the water outlet. It's the only bolt that isn't obviously holding anything on. Oil is gonna pour out, even if you thought you drained all the oil. That's what the rag was for.
  44. Go get your turbo out of it's lighted display case in the living room.
  45. Make sure your coolant hard pipes are bolted to the turbo at this point, they don't have to be connected to the hoses yet though. Fit the turbo into place and estimate the position your upper oil feed line will have to be in... now take the turbo back out and bolt the line onto it. I found it easier to bolt the line to the turbo before mounting it up, but you might beable to do it after the turbo is in place.
  46. Make sure your oxygen sensor and O2 sensor housing are bolted to the turbo. Bolt the turbo up to the manifold, using a new gasket.
  47. Bolt the upper oil line to the head with the banjo bolt and copper washers. Bolt the lower oil line to turbo and to the oil pan, using new gaskets.
  48. Plug in the oxygen sensor and make sure the wire's routed properly so it doesnt melt.
  49. Now on to the coolant lines... You have a few options for the coolant lines. You could do like I did, and route them inline with the coolant hoses that run through the throttle body, which is easy, safe and reliable. You could also get the stock turbo lower coolant pipe and the turbo water outlet and run them like a stock turbo car would. That's the hard way though. The line you would need to tap into to run it with the TB coolant is the one under the TB, that goes from the TB to the lower coolant pipe. This allows the coolant to flow through the TB first, then to the turbo. I originally used 3/8" fuel injection hose for these lines. Don't. After about a year the lines were so hard and brittle I was able to tear them apart very easily with my fingers. Use automatic transmission cooler hose, or 300psi hydraulic hose (Gates LOL+ or Weatherhead work well), it's oil, coolant, and fire resistant. Lesson learned.
  50. Get under the car and bolt your downpipe up. Use new gaskets. Don't forget to bolt the ground wire to the pipe.
  51. Bolt the wastegate actuator on.
  52. Install the turbo outlet pipe (J-pipe), use some silicone to seal it. Connect the vac hose from the wastegate actuator to the nipple on the J-pipe now. This is the line you would use when you install a boost controller.
  53. Install the lower IC hose.
  54. Put the exhaust heat shields on, and slide the O2 sensor wire into the clips along the top of the upper heat shield.
  55. Pull the spark plug wires off and regap the plugs to the spec for the turbo cars (.028"). Reinstall.
  56. The vaccume lines... First off, put a vaccume tee into the line between the FPR solenoid and the intake manifold. Run a line off this tee across the back of the engine to the BOV. Put a tee into the BOV line and run it to your boost gauge.
  57. Get that vaccume check valve and put in inline in the vaccume hose between the throttle body and the purge control solenoid. Make it so you can suck air toward the throttle body, but can't blow air into the purge control solenoid. This is what keeps your car from stinking of gas fumes when you're under boost. It's alot easier and cheaper than converting to a turbo purge control system. The only downside is that cheap check valves will blow out every few weeks. Better to get a good quality all metal check valve right from the start, they last forever.
  58. Now you can bolt the aircan and intake tube in. Connect the BOV return and the breather hose that goes to the valve cover. There's a small nipple on the back of the aircan, it used to go to the BCS, but now it goes nowhere (unless you installed the BCS). Cap it off.
  59. If you disturbed the TPS or closed throttle switch, adjust them back to factory specs. Check your ignition timing while you're at it. Should be 5 deg BTDC at 750RPM idle with everything shut off.
  60. Let the car sit till all the sealer cures if you used any (overnight is best).
  61. Refill the oil, transmission fluid, coolant, and add clutch fluid if needed.
  62. Have a friend look over everything, and double check it all yourself. Check to make sure all the hose clamps on the coolant, fuel, and IC pipes are tight, and make sure all the vac hoses are connected. Make sure you tightened the banjo bolts on the oil line and the bolts on the oil return tube.
  63. Connect the battery and crank the car. It may take a few seconds of cranking till it fires, the fuel system has to purge the air out. Shut the car off a few seconds after it starts. Check for fuel, coolant, oil, transmission fluid, and clutch fluid leaks now.
  64. If everything is ok, restart it and let it idle for a minute or two and shut it off. Let it sit for 5 minutes and check the oil and coolant again.
  65. Start the car back up and let it warm up to operating temp, check for leaks and check the fluids again.
  66. If it's running ok, take it for a short test drive... and take it easy the first time out. The car might run a little bit weird at first or stall the first time you come to a stop, but it should smooth out after a few minutes. The ecu has to learn everything and it takes a few minutes.

    Now for the rant about boost pressure and premium fuel. (If you're using stock non-turbo pistons) You have 9:1 compression, with fairly fragile pistons and boost. You have to run premium gas. You just spent all that money to make your car faster, dont be cheap with the fuel. If you don't run premium fuel, you'll destroy your engine... simple as that.

    Boost Levels...
    If you absolutely need you car to be reliable, run the wastegate signal directly from the LICP nipple. This should give you 8-9 psi. If you did the conversion right and are running premium, this much boost is perfectly safe, and will give you about 190hp with no other mods.
    If you take some extra measures against detonation, you can run higher boost with no reliability problems. On my own car, I have a MKIV supra sidemount IC, base timing retarded to 3 deg BTDC, and an upgraded fuel system set to run a 10.5:1 AFR at WOT. I run 19psi of boost in the winter and 17 psi in the summer, and have been for 3 years and about 50,000 miles of daily abuse. As far as I know I'm the only person to run that much on a stock NT engine for that amount of time (if you know someone who has run more with success, email me). I'm also looking at water injection so I can run 19psi year round. At 19psi I'm making enough power to keep even with a stock supercharged Mustang Cobra from a 45mph roll. I figure I'm just over 300hp, and it should run low 13's in the quarter if I can get traction and turn a good light.

    If I left anything out, or made any mistakes, email me.(see bottom of page)

    If you have any problems or questions about the conversion, do a search of the forums at www.dsmtalk.com and www.dsmtuners.com. This topic has been beaten to death on both of those forums already, so try not to create new threads about it unless you really can't find the answer by searching. If you can't find the answer anywhere else you can email me at this email address... rightspeedservice@yahoo.com . If I don't answer you, it's because you asked a question that I clearly answered on this page. Read this page twice before you email me. I get tons of email from people with questions like "I read your page and it was very helpful, but do you have a list of parts I need to do a conversion?" and "do I really need a turbo fuel pump and a knock sensor, or can I just leave them out and puke my connecting rods all over the interstate instead?"



    This VFAQ may not be copied onto another website without permission of it's author. Link to it instead, please.

    - 12/11/2002 - Joel Mashack (destrux on dsmtalk.com and dsmtuners.com)-
    Updated- 7/3/07
    Updated Regularly...