Builds DIY FJZ80 Low Budget Turbo Build

[alia176]

You *could* use the oem battery box for a '92 and place your air filter inside it for a little cooler air. Unfortuantely, this will force you to relocate the windshield washer res. Slee sells this bracket relo kit.

Just a FYI.

 

[scottryana]

Yep that is exactly what I am going to do. Seals off fairly nicely from the engine bay. I think his air filter might be a little to large to work though and he is looking for the most power possible on the given setup.

 

[alia176]

Forgive my ignorance but wouldn't the oem canister be a good way to get fresh, cool air into the engine while doing a good job of cleaning the air using cyclonic air movement? Seems like sucking air from the engine bay is going to be hot, especially on that side of the engine, no? Of course a snorkel is the best way to go if possible.

 

[NKP Garage]

Forgive my ignorance but wouldn't the oem canister be a good way to get fresh, cool air into the engine while doing a good job of cleaning the air using cyclonic air movement? Seems like sucking air from the engine bay is going to be hot, especially on that side of the engine, no? Of course a snorkel is the best way to go if possible.

Yes, but the OEM air box and all the baffles that come along with it, is more restrictive than a straight intake.

 

[concretejungle]

Just FYI, and it's not even "hot" outside yet in my neck of the woods... but i have an ultra gauge and a snorkle. Wanted those with my supercharger. Been watching the engine temps and the intake temps. Yesterday with it being approximately 80 Degrees outside, i went to drive the truck and at first start-up the intake temps went to 96 degrees in a matter of 30 seconds. I can't imagine how hot they would be if it were 95 degrees outside and the motor had been running for an extended period of time, and, the intake was pulling air from inside the bay!!

 

[alia176]

Yes, but the OEM air box and all the baffles that come along with it, is more restrictive than a straight intake.

Very true and the remedy to that is to simply remove the air silencer (the rear part as shown in the pic). I did this on my 80 and this opened up another source of air intake. Or, one could simply remove the whole thing altogether. If anyone is curious, the opening to the round canister is 3.25".

Not trying to derail this thread, was simply curious.

 

[scottryana]

While the stock IAC temp is good to look at, a more realistic number to look at would be the post compressor air. I bet a stock supercharger without an intercooler, has higher temps post compression than an intercooled turbo, no matter where it pulls its air in from

 

[lilevo]

The air filter intake temp is negligible. The turbo spits out 250-300 degree compressed air. The difference between 75 degree and 95 degree intake temp is splitting hairs.

Air box comes into play when you are stopped and it heat soaks. When you are moving the air filter temp is ambient.

If I ever off roaded I would do a battery box heat shield or stock air can, but in reality it never goes off road.

 

[lilevo]

Ok, I installed a Supra TT pump.

I also rewired the pump with 10 gauge wire from the battery to a relay. Cut the thick blue wire on the fuel pump harness. The car side turns on the relay. The pump side goes into the relay. The ground on the sending unit is visible and riveted to the sending unit body.

This bypasses the resistor and ensures the pump has full battery voltage at all RPMs.

The bigger pump didn't change the top end lean out.

So I'm guessing stock injectors won't cut it for 8psi+ at WOT. Normal driving and part throttle is fine, but it is way too lean at wide open.

I used the URD FTC to richen the fuel map, and it worked to an extent, but it is richened past the stock MAF range and throws a CEL. With the FTC set to stock settings AFR's are over 14 at wide open.

So, 450cc injectors are needed. I will be ordering the Denso 854-450s from www.efihardware.com

I'm guessing if you ran my exact setup at 3-4psi the stock injectors and pump might work out fine. You might be able to add more boost if you run a smaller exhaust or a more restrictive intake or stock airbox.

 

[Riad]

Awesome! So you ditched both of your O2 sensors and replaced them (or their functionality) with your simulator? If so, is there a way to keep them or probably upgrade them to something else? I wonder how the emission test would go for those who would have to figure out a way to retain the emission components with your exact setup...

 

[lilevo]

No emissions by me so that doesn't matter, but it doesn't throw any OBD2 codes and that is what matters.

Rear O2 is gone with a simulator and front O2 is oem. No change.

Only addition is a wideband so I can tune at wide open throttle.

 

[lilevo]

Knock Sensors:

My truck has 238k on it and I never had problems with the knock sensors. My first test drive with the turbo kit threw both knock sensor codes. I just replaced them both with aftermarket ones on ebay $70/each. Codes went away. If you don't replace them, the truck will be very doggy due to pulled timing.

If you are adding forced induction, replace your knock sensors!

 

[lilevo]

I am able to wire in my AEM wideband into the 0-5V input of the URD unit and log AFR along with all of the fuel timing controller values which will make tuning simple.

Turns out the FTC units from URD do NOT have any data acquisition features and they can't get one for you. Split Second DOES have the unit with D/A, but retail price is like $650 or something and $600 for the same unit at URD.

I'm not going to buy another FTC for almost $300 more just to log wideband.

 

[scottryana]

That is interesting Brett had the same issues with the knock sensors in his truck. I had mine replaced when I did the head rebuild.

So no wideband logging are you just going to tune off of the AFR gauge?

 

[lilevo]

Yes, I will just have to watch the gauge while tuning instead of reviewing data while stopped. No big deal.

 

[concretejungle]

interesting about the knock sensors. I wonder if that's one of my issues since i'm for sure getting some power cutting back. I replaced one of mine when i rebuilt my motor since i broke off the connector, but i replaced with an old used one.

So your front O2 sensor is what helps determine fueling right? I am assuming that is why you did not try to turn it off with a simulator?

 

[lilevo]

Bad knock sensors would throw a CEL. No CEL, then it should be fine.

Front O2 is what the ECU uses for fuel trims. Idle, part throttle, and everything other than wide open to simplify it. The ECU shoots for 14.7 AFR at all of those conditions.

 

[lilevo]

I think my MAF is getting overrun. Anything more than part throttle over 6psi and it jerks and AFRs go lean. I also occasionally get a MAF CEL.

I ordered a voltage clamp from URD. Will report back with findings.

 

[landtank]

In my initial testing I saw what I believe was a point of saturation with the stock MAF at the point of transitioning to boost. It was something that wasn't present with my modded MAF. It was during testing on a Safari turbo'd truck.

The data logging software while displaying the lbs of air flow would suddenly drop to 0.

 

[lilevo]

I will have to check that.

I can wind it out in L to about redline and afr is a little lean at 11.7.

If I try winding it out in 2nd or higher at around 3200 rpm it goes lean, cuts out, and basically jerks like I'm out of fuel.

Too many variables at this point to say its the maf, injectors, or other problem.