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240's KA24DE "truck motor" turbo build

37K views 289 replies 14 participants last post by  240 
#1 ·
 
#149 ·
I'm about to start some major surgery on my 240, this is motivating me. Keep it up.
 
#151 ·
Hell yeah!


I got the first startup on my RX7 tonight, but I've already traded it off. I'll barely get a chance to drive it before it's gone. But it's being replaced by a better base for the build so it's all good. Getting my hands on a metric shitton of new parts for my 240 in the next couple weeks also, so I may go ahead and pull the engine and get started on my rebuild too. Just need motivation lol
 
#152 ·
Awesome bro, love the video logs. Sounds like its running great, Idling nice too. Have you checked the tank yet to see how much accumulation there is?
 
#153 ·
I watched the video on my phone today and the exhaust sound is just horrible. Sounded like static. In person it is very deep and not all that loud at all. I don't know if that's my phone's fault or from the camera I used to record it.
 
#154 ·
I watched it on my PC and it sounded fine.
 
#155 ·
^ yup
 
#156 ·
I'm up to 130ish miles. Still on Rotella 15-W40 , 3rd oil change. I'm trying to simultaneously break-in a motor, a clutch, and new pads/rotors. So far so good.

My right rear brakes are making a noise as the slots pass the pads at low speeds. I'm not hearing anything from the other 3. Need to see what's going on with that.

New issues to address, in addition to the brakes:
1.) A/C blows cold before the engine warms up from a cold start. Then it's nothing but warm/hot air whether the A/C is on or not. I'm thinking the electric motor that controls the hot/cold blend door is out or on its way out...?
3.) Fix fuel gauge (stuck on Full)
3.) Zeitronix Ethanol content gauge display shows a different % than what I see in Nistune: 10-11% vs 25%
4.) Very small oil leak where the upper oil pan meets the lower timing cover....
 
#157 ·
Damn The Oil Leaks!!!
Not too familiar with the 240 hvac system, is electric or vacuum actuated?
 
#158 ·
I know, right? This leak is pretty minor compared to last time. But still, it's frustrating.

The HVAC setup is all electric. When I slide the temp from hot-->cold, I can hear the electric motor moving. Either it's not Mo img enough, or I've got something else going on.


I'm going to try and get a video of it on the road today. The cam timing changes really moved the powerband down. The turbo spools quicker and it's got so much more low end torque. Even though I'm still only on 5 psi, it feels much faster than last time. It does feel like it falls off a bit as I get up near 6K. I haven't take it past 6 yet and probably won't until it has more miles on it.
 
#159 · (Edited)
Quick 5 psi video. I was trying to capture how loud the turbo is @ only 5 psi. It's still much louder in person. It's all I hear when my window is down.


This cold air is awesome. Car feels like it picked up 10 hp just from that alone. I'm now running 8psi and it feels faster than my supercharger setup did @ 12-13psi.
 
#160 ·
Hell yeah bro sounds good. What will be the final psi you will be running and what kind of power are you expecting?
 
#161 ·
The plan is to have it setup as a flex fuel vehicle so that I can run gas or corn of any mix. On corn, I plan to push it to over 30psi. I've got a number in mind that I want to hit, but don't want to jinx it by saying it.
 
#162 ·
I'm too lazy to dig all the way back through your thread lol what are you using to determine the fuel/ethanol percentage and what ecu? I'm getting ready to start rebuilding my SR, and I want to go corn, but I'd also like the ability to switch maps from regular gas to E85 if necessary. Just curious what you're using so I can look into it a bit more.
 
#163 ·
I'm running the same S13 Nistune ECU that I have had in the car for 8 years now. And for ethanol content analyzing, I am using a Zeitronix ECA-2. It has an analog output that goes to the ECU and Nistune uses this to adjust flex fuel maps.
 
#164 · (Edited)
This seems bad




And before anyone says it, my throttle cable is setup so that the gas pedal will hit it's stop before the throttle body pulley hits it's travel limit. So, this is not an issue of lead foot syndrome or a poorly adjusted throttle cable! I remember at one point doing something to my throttle body and I looked down and realized that the pulley had inadvertently gotten bent. I bent it back and didn't give it another thought. But, if you look closely, there is some copper looking stuff at the break point in the second pic. It looks to me like it was just brazed on at the factory, which isn't going to hold up to repeated bending like a one piece or welded piece would.

Anyways, I had to buy another throttle body just to get a replacement pulley.

In other news, the car is doing some weird stuff all of a sudden. Sometimes I will punch it, and I only get ~1 psi up until 6000 and then it suddenly shoots up to 15 psi before hitting the 7200 rpm limiter. My wastegate is a used Precision 46mm so it already had some use and miles on it prior to my car. It's like the wastegate is stuck open or the diaphragm is busted. I originally thought it was some changes I made on the boost controller, but it does the same thing with the boost controller's power disconnected. So, I'm thinking that it's either a busted diaphragm or an issue with the boost solenoid.


P.S. 15 psi feels awesome for the .2 seconds that I get to feel it. It just spools hard and rockets forward at 6K and I can feel myself getting pushed back into the seat. I wouldn't be surprised if it was putting down 80-100 whp more than my supercharger setup ever did.
 
#165 ·
I pulled the wastegate and the diaphragm was fine. However, the valve shaft as well as the hole/guide both looked very rough, as if something sandy/gritty had gotten in them. I played around with it and even with the spring still in it, it was definitely getting stuck open just due to the friction at the shaft. I don't know if something got down in there or...? I ran a soft wire tube brush down the hole several times (in a drill) to clean it up. I used some 1500 grit sandpaper (wet) and a drill to polish the shaft. It's smooth like butta now, but I'm a little concerned about the longevity and if it will happen again. However, a new WG is $350...!

I didn't take any before pics, but here is the shaft after polishing with the 1500 grit.



It was anodized black when I installed it. Now it's like a brown copper color. Weird
 
#166 ·
due to the friction at the shaft (gigitty)
Yeah all my black AN oil return lines did the same thing. Guessing its from the heat. Glad to see you made some progress. Have you ran it since reinstalling it?
 
#167 ·
Yes, it worked great for the past several days. Took a friend for a drive today and it started sticking open again.

So, I pulled it off and this is what it looked like. The valve is stuck open about 1/4". I can break it free but when I pressurize it to open it, it sticks open again.


I'm calling Precision Turbo in the morning to see about having it serviced. If that's not an option, I guess I'll have to bite the bullet and buy a new one.


And this is cruise control pulley V2.





I was real careful not to bend it this time or overheat it from welding. So... finger's crossed
 
#168 ·
Sent the wastegate back to Precision for service. Hoping to have it back by next week. In the mean time, I'm fixing other little issues that I have been meaning to get to. For example, I had to run a wire to the distributor to get the tach signal for my boost controller and TXS knock light. That's done. I needed to hook up a push-button switch for activating launch control. That's pretty close to done.

And I needed to figure out why there is a discrepancy in ethanol content % when you compare the Zeitronix hacker display vs what is displayed in Nistune:
 
#169 ·
Good little video, Hopefully some one on said forum can help get to the bottom of this.
 
#171 ·
Got them big injectors in? I take it it's time to turn shit up a bit more?
 
#177 · (Edited)
Bosch 1600cc. I sold the 2000cc and used the money to get these.
You're getting me motivated to do shit to my 240 too. Been working on my RX7 too much. It's up and running now though, so I spent the last couple nights pulling my spare SR20 apart and laying everything out and checking clearances. If everything lines out I'll be dropping it off to a machine shop in the next couple days to get cleaned, honed, prepped, and ready. Keeping it mild for now as well, once it breaks in the big injectors and turbo will go in with the standalone and E85 and I'll also turn it up to 11. I'll have to swap trans then though, I'm shooting for 550 so the stock one will NOT make it lol. Got a G37 6 speed lurking in the garage, wanting some action.
Hell yeah. My eventual power goal is around the same. You'll definitely be a lot lighter than me though.
I could revive half the car specific forums on here just taking and posting pics of the cars I currently own lol. Let's see....RX7, RX8, 240sx, '16 Mustang GT performance pack, 15 Taurus, 88 Fiero, 89 Camaro Iroc, Dodge Ram, Isuzu Trooper....
I'd love to do a fun run against the GT (on 93oct @ 17psi). I know where I stand against several of the new muscle cars. I imagine it would be a good race.
 
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