On3 Performance Install Tips


10 Year Member
Dec 6, 2007
SE Georgia
I am in the process of installing my single forward facing front mount turbo kit from On3 Performance. Below is a list of things that I came across along the way and hopefully they will help someone else. As I keep installing the kit I will keep adding to the list. Sorry that there are no progress pics. I don't have the time to take pics and work since I have VERY limited wrench time. SO, here goes:

1. Obviously, you will need the tubular front end kit. I prefer the UPR stuff. I matched it with the Strange single adjustable shocks and struts with the UPR rear coil over kit. You MUST use Fox body shocks and struts or, you will bottom out on the SN95 ones.

2. Do the exhaust manifolds with the K member out of the car. Trust me. I tried with the new K member in and I gave up. This way you can raise and lower the engine as needed to allow you adequate space.

3. Replace the oil pan gasket while you have the k member out of the car.

4. I would recommend spending the money on the upgraded oil filter relocating kit. There is nothing wrong with the included one but, the upgraded one is better quality and I think it looks better.

5. Install the oil return fitting into the oil pan while you have the pan out of the car. I tossed the oil return fitting for the oil pan and ordered one of these no weld/tap fittings instead: View: Amazon product
View: https://www.amazon.com/Turbo-drain-return-adapter-fitting/dp/B00FB33POO/ref=sr_1_13?keywords=turbo+oil+line+return+fitting&qid=1576454186&sr=8-13

6. Remove the sway bar while you install the kit. Trust me on this one. Besides, you get new extended length end links in the kit.

7. When doing the exhaust, remove the motor mounts and starter for added room. I unbolted the a/c compressor too. I didn't really need to but, it did help.

8. Replace the motor mounts. Period. Unless they are fairly new, replace them while you have the access and room. I found both of mine were bad.

9. Throw away the supplied exhaust manifold gaskets. They are garbage and On3 even recommends replacing them in their instructions. I used the FelPro ones.

10. Throw away the new exhaust nuts/washers supplied with the kit. Replace all the exhaust studs and nuts with new ones. The parts store has them in the HELP section.

11. You will need to remove about an inch of the flange on the drivers side manifold to allow for clearance the dipstick tube.

12. You can use the factory exhaust studs and lock nuts on each side except for 1 on each side. It's so tight on those 2 primaries that you can't even put one of the supplied bolts in.
a. I was not about to take a hammer to brand new headers. I remedied this by taking an old exhaust stud that came of with the nut intact. I used it for reference for length. I took one of the new studs and tightened down a factory lock nut to the proper length. I then took a hack saw and cut off the excess length. I removed the lock nut. I took the new shorted stud and installed in the manifold from the back side of it. I then put the nut back on and tightened it down flush to where it was cut off. Now, the stud/nut is on the manifold and cant come out. Repeat the process for the other one on the other side
b. When installing the manifolds, start the pre installed stud/nut by hand first. Once you get that one going, the rest will go right on with no problem.

13. I replaced the upstream O2 sensors just because I had a lot of miles on mine. The passenger side will fit no problem. The driver side will need an extension or, I made an extension from the wires cut off one of the old sensors in my old X pipe. On a side note, the O2 sensors will be much easier to service with the turbo kit installed.

14. The kit comes with a EGR delete plate. Don't order one like I did. Oops.

15. The fuel pump requires some more electrical work than just a plug and play so, I ordered a better one that was plug and play.

16. Spend the money on the welding service for the MAF upgrade. They mount it right in the factory location on the intake tube.

17. Use copper RTV on everything you can.

18. Paint the headers. I just did black to help keep the rust to a minimum.

19. If you can, spring from some AN fittings and lines for the oil return coming out of the turbo. There is ZERO, I repeat ZERO room to put a hose clamp on the hose for the oil return. If not, or, you are in a hurry like I was, I used some crimp on stainless steel hose clamps similar to those that would be used on fuel lines. This stye clamp or the AN style will make clocking the turbo much easier as well since space is at a premium down there. The same could probably apply to the oil filter lines.

20. Remove the radiator and fan assembly. It will create much needed space for your hands to install the turbo to the merge pipe. It comes out and goes back in in just a few minutes so, you will save time in the long run.
- i would also suggest a thinner fan if you can afford it. the little bit of room that it would create would be helpful

21. If you have a drive shaft safety loop like I do, it will need to be removed, relocated or, a different style used. I have the UPR safety loop and it interferes with the exhaust. So, that's gotta go.

22. When you do the oil filter relocation kit DO NOT have it parallel to the ground facing the rear of the car. If you do, you will not be able to get one of the oil lines onto the fitting. Instead, have it turned so that the fitting are facing at about the 4 or 5 o'clock position.

23. For the oil filter relocation I made a bracket and mounted it on the bottom 2 bell housing bolts of the transmission on the drivers side. That way I only had to run about 10 inches of straight hose instead of looping several feet around the engine compartment to the back of the bumper where most people put it.

24. The new version of the kit DOES NOT come with the new power steering cooler to be routed in front of the intercooler as pictured on their website. I removed the power steering cooler and just looped the lines together with a brass barb and a couple of hose clamps.

25. when wiring the MAF pigtail:

Starting with the BROWN wire and working right to the ORANGE you will have:

Brown Pin 1: IAT sensor signal
Brown Pin 2: IAT signal return
Green/White Pin 3: Mass air flow sensor, signal
Yellow Pin 4: Mass air flow sensor, signal RETURN
Green/Black Pin 5: Ground
Orange Pin 6: voltage supplied in start and run

If your installing this on a 87 – 95 car, splice the following

87 - 95 Harness Pigtail

RD Orange
BK Green/Black
TN/LB Yellow
BL/OR Green/White

If you are wiring into a 96-04 car, you will splice the following into your factory harness:

96-04 Harness Pigtail

GY/RD Brown, 2nd from the Left
RD Orange
BK Green/Black / Light blue 2nd from right
TN/LB Yellow
LB/RD Green/White / Light blue 3rd from right
GY Brown, Far Left

IF YOUR CAR HAS A SEPARATE IAT SENSOR**** Just delete the sensor and connect the 2 wires from that harness to your 2 brown wires on the pigtail. Polarity does not matter on this 2 wires

26. When hooking up the On3 Gauges I Used an add a circuit and went right into the fuse panel.

Red to Add a circuit
Black to Ground
Orange to the blue/white wire on the back of the dimmer switch

On the AF gauge, if you are not running an aftermarket computer, nitrous controller, ect the white wire is to be left alone.

27. Turns out the oil filter adapter that screwed down to the engine block had a hairline crack in it and was oozing oil out when the car would run. On3 warrantied a new one to me no questions asked immediately over the phone. Great customer service! However, I ended up upgrading that part to the Moroso one pictured below. It was easier to install with the headers still on the engine and, I didn't have to worry about the plugs on the other ports or, taking forever to get the adapter to line up right.

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Hello. Thank you so much for this post its been helping me out a ton. I have been trying to figure out the vacuum lines for the blow-off valve and wastegate, and I just seem to keep getting stuck on where to get the vacuum source from. Many people are saying the intake manifold, but I am not sure where that is and what the lines look like. Would you be able to supply some visuals of where the BOV and wastegate lines go?