Irace86.2.0's KPower Turbo K24 Swap

[Irace86.2.0]

Originally Posted by RedReplicant

Just be warned that the K is really sensitive to high cell count cats; HFC is really close to no cat, but oem to hfc is a pretty decent chunk of power.

Also, look at your corrections table in Haltech.

I’ve looked and my tuner has looked. Long term fuel trims are fine.

My power goals are limited by my transmission and then the engine. The turbo will make enough regardless of cat or not. A car would normally have two cats, so going to one is still something.

[Irace86.2.0]

I got a free, OEM frontpipe thanks to @Clipdat. Today, I began the process of redoing my downpipe and frontpipe. I was able to cut off the mini-muffler and cat from the stock, 2.25'' frontpipe, and I welded it in position on the larger, 2.5'' frontpipe. Everything looks like it is going to fit well. I might even be able to use the stock heat shields over the cat.

I had some exhaust penetration through the edge of the flanges on the wastegate, but it didn't penetrate all the way through, as there was no soot on the outside. The lock washer wasn't enough, and the bolt was a little loose. I am going to triple up with some high temp RTV and an extra, nylon lock-nut, which should have come with the wastegate, but it was a cheap version. I think part of the problem was not getting to put the flex pipe into the wastegate loop of the downpipe because of lack of space, which I plan to rectify the second time, so I can guarantee a solid joint. As it was, the clamp was likely holding off an exhaust leak, which is why I didn't get any exhaust leaks when I tested the system or changes in long-term fuel trims.

I bought a new, 3'', downpipe-to-frontpipe flange, which means I can use the old, 3'' clamp on the turbo-to-downpipe flange, which is better than the old flange because it has a larger bolt, so that should guarantee a better seal, even though there was no sign of exhaust leaks there. There are some advantages and disadvantages saving $1500+ on turbo components.

Tomorrow, I should have a shipment of parts coming in. I should get close to finishing tomorrow, if the pipes come in on time. I might have to finish things up on Wednesday. I bought a hanger rods and rubber mounts, so I will also try to get that done over using the stock, hard mount; it doesn't really fit well with the current mini-muffler.

I also did the first oil and filter change. The strut tower bar disassembles by removing two bolts without having to remove the strut mounts, which is nice, as I went to bolts over studs. Since I had the tray off the oil change went well. It isn't as convenient to change the filter, as it was on the FA20.

[Irace86.2.0]

I finished the exhaust components. It wasn’t easy, but I got it all in there. All I have left is welding on the hanger rod. Then I need to clean them, wrap them in header wrap, and I need to mount it all back up. The downpipe and the dump tube have flex couplers. The dump tube attaches to the frontpipe past the cat to maximize flow under boost and to get a louder, sound note when the wastegate finally opens. I was able to integrate the mini-muffler, so the car should be pretty quiet. Hopefully the sound is good. I’ll get some pics when it is all finished.

[brzlegend]

Originally Posted by Irace86.2.0

Why do you think I have a leak? The smell? My wideband isn’t showing any abnormalities like a lean condition. I don’t feel a leak. Are Berk high flow cats three way cats? Either way, I’m going back to the stock cat.

Yes, the smell.

[Irace86.2.0]

Originally Posted by brzlegend

Yes, the smell.

Smell was coming from the tailpipe. It was obvious just moving around the car. Under hood smells weren’t bad. Under hood smells were dominated by my header wrap. Rear was bad eggs.

[Irace86.2.0]

Here are a few pics. Frontpipe looks pretty crazy with the long dump tube. I added a few pics below to show mine versus some long tubes I found online. There are space constraints for two flex couplers, both pipes, a flange and a cat. Best I could do with limited supplies and a basic garage. Hopefully it all works out. I plan to mount it all up today. Crossing fingers it was worth the effort. There is no going back at this point.

My solution for the exhaust hanger was to bend the stock hanger, drill and bolt it to the transmission mount, use the bolt hole for the top loop, and then I welded the hanger bolt to the frontpipe. This should allow more movement, but take stress off the frontpipe to catback flange.

On another note. I noticed some coolant leak from the rear pipe going to the radiator at the rear water housing outlet. It doesn’t seem like a lot or constant, so I’m wondering if it is getting super hot before the thermostat is opening, or maybe the weakest link in the system is that rear worm clamp. I used OEM clamps everywhere else, which can expand when pressure builds, and I think are better than worm clamps. Maybe vapor is squeaking through. The clamp is plenty tight, so I don’t know why the radiator cap didn’t purge the extra pressure into the overflow tank. That pipe is pinned against the wiring harness, so maybe it gets pressure or resistance with engine movement. I don’t know. I’ll keep an eye on it, and I’ll probably do the coolant mod eventually to add another line, so the thermostat opens as soon as possible.

[captain awesome]

Originally Posted by Irace86.2.0

On another note. I noticed some coolant leak from the rear pipe going to the radiator at the rear water housing outlet. It doesn’t seem like a lot or constant, so I’m wondering if it is getting super hot before the thermostat is opening, or maybe the weakest link in the system is that rear worm clamp. I used OEM clamps everywhere else, which can expand when pressure builds, and I think are better than worm clamps. Maybe vapor is squeaking through. The clamp is plenty tight, so I don’t know why the radiator cap didn’t purge the extra pressure into the overflow tank. That pipe is pinned against the wiring harness, so maybe it gets pressure or resistance with engine movement. I don’t know. I’ll keep an eye on it, and I’ll probably do the coolant mod eventually to add another line, so the thermostat opens as soon as possible.

I had a similar weeping from what looked like the worm clamp as well. I couldn't manage to situate or tighten the clamp enough to make a difference. I also think re-using the gasket from the donor was a bad idea. So I replaced the gasket and also the upper hose but left a little more length to take the stress off of the joint. Not sure if that makes sense or not though.



In the end I agree it was probably excess pressure causing it to push coolant out the hose ever so slightly, and possibly even the gasket. Before adding the second thermostat hose, the hose on the passenger side was bulging and super hot while the passenger was cold and soft. It no longer builds that sort of pressure on the passenger hose.

[Irace86.2.0]

I drove the car around today, and the exhaust is a million times better for me. Remaining vibration is still there, but much more livable than day one. The decel noises from the transmission are there, and I think having the open transmission is the main cause of it being much louder than before. But, the rancid exhaust smell is gone from the tailpipe and isn't saturating the air at stop lights. The cold start is much better. The car sounds just less obnoxious, and it is more mature and smooth in the note. This is especially true driving around. It was hollow and raspy before, and it was loud, but now it is smooth and even in tone. There was mild drone on the highway before, but there is none now. I can hear the turbo spool and BOV much more now, and when the car goes WOT with the turbo, there is a rush of air and higher pitched, yet quieter exhaust note, but then the wastegate opens and some exhaust routes around the cat and elevates the exhaust to something more angry and loud, but still, not overwhelming. It is perfect for me. The car is going Wednesday to the dyno, so hopefully I'll have something to post then. I'm wanting to be conservative in the 350-400whp for reliability with the engine, but mostly with the transmission until after nursing school.

Also, I ran the car until it ran out of gas and died, so the car is ready for the dyno with E85. It indicated 5/16-3/8 of a tank when it died. I filled it up with 4.5-5 gallons of E85 from a jug in the trunk. Then I filled up 8.7 gallons of E85 at the pump. Unlike my previous event, it appears the gas is being siphoned correctly from both halves. Hopefully Haltech will be releasing an update soon. I'll ask my tuner/Haltech dealer about it on Wednesday.

I plan to rent the vacuum pump and AC manifold from Autozone on Monday and attempt to fill the AC system myself instead of trying to find someone willing to work on a modified car who will charge me $250+ for something I should be able to do. I believe all I need to do is hook up the high and low to the manifold. Pull vacuum. Let the car sit for 60 minutes and see if vacuum pressure is holding, indicating no leaks, and then I can attach a standard refill canister to the system to fill it up. Shouldn't be too hard.

[Irace86.2.0]

[Irace86.2.0]

Went to the dyno today. It was my first time operating a car on a dyno. It was a different experience, but fun...up until the moment we started having issues. We were getting some boost drop off, so I think one of the HD clamps is leaking. All the other ones feel firm, but one feels loose. I don't know if the o-rings are getting so hot for this clamp coming right off the turbo. Honestly, I wish I would have just gone with some silicone couplers than all these HD clamps. They look nice, but the extra cost was far more than it was worth. I'm not entirely sure the HD clamp off the turbo is the problem for sure, but it is my best guess.

We made 355whp and 278wtq at 8psi with this Pulsar GT25-660 replica. Here is the dyno of that pull. The subsequent two pulls have this boost drop off, but he worked on VVT to smooth out the curve, but we had more work to do when there became a clatter. At first I thought it was just some dyno or transmission rattle on decel, but then it grew super loud like knock or something in the head clicking. Well, we decided to call it a day.

We pulled the valve cover off and turned over the motor, and everything looked great. There didn't seem to be signs of wear, a thrown rocker or valve drop or anything. It didn't sound like rod knock. My tuner said I was pulling 22+inHg of vacuum. Oil pressure was good. I towed the car home, and I began pulling apart the transmission because I had a suspicion something was wrong there. Well, I had bought some ARP flywheel bolts specifically to prevent the bolts from backing out; the flywheel bolts backed out. Every bolt except for one was hand loose or all the way butted up against the flywheel. Well shit. I followed the instructions by putting grease on the head, so they don't bind, and all were torqued to specs plus 5lbs (100ftlbs) plus a quarter turn or something, and I used the required blue Loctite 242, but maybe I needed to use red considering the vibration on this motor. I'll be using red next.

When we removed the head, I found multiple loose bolts and AN fittings, even though I tend to torque things down and give it a little extra and then some. Dam this engine's vibration is killing me , but maybe part of my vibration problem was these bolts slowly backing out, and maybe, hopefully, I will get it all together, and the vibrations will be less. I know there is less vibration between the tune and harmonic damper, but maybe the bolts were already on their way out. Crossing my fingers that everything can be put back together, and when I start the engine, this was the only issue. I'll head back to the dyno to dial in the power curve, do boost by gear and add a little extra power. We will probably do 10psi max.

[Irace86.2.0]

Update: the flywheel is too damaged to resurface the bolt area, so I have ordered a new flywheel from Kpower. I have no idea if these are in stock. Hopefully it isn't a long wait. I'm hoping days and not weeks or months before shipping, or I am really screwed.

On a good note, maybe some of the decel and excess drivetrain noises I have been complaining about were these, but it is odd it only materialized going 135mph on a dyno, or is it? Hopefully the noises from the dyno day are just this, and I'm pretty sure that is the case, but after installing everything, I am hoping some of the "normal" vibration and noise I was dealing with will go away. This kind of explains why some times the car would feel super smooth and other times it was all wonky.

My theories about the flywheel bolts backing out are as follows:

1. Maybe the bolts weren't original ARP bolts. I bought them off eBay because I read about bolts backing out and wanted protection, and they were going to get to my door in a short, predictable timeline versus the dealer being ambiguous by 4-6 weeks. The owner said he bought them in bulk and then repackaged them. They look legit, but they could be fake and slightly longer or something, so the bolt could have bottomed out, but I don't think it did. I think it is less likely that this was the issue.

2. The last option could be that despite the instructions, these bolts backed out on their own with all the vibrations. I will be using red Loctite next time, and I don't think I will use any grease on the heads. Maybe I was too liberal with the grease and too conservative with the blue Loctite, or maybe they combined in the process, and the grease messed up the Loctite. I don't know. They provide a lot of grease for eight bolts. I think I will just do a super thin smear on the wheel surface instead of trying to coat a glob on the head surface. That should be easier to get something really thin and keep it away from the threads, and I will be using OEM, 17mm-head, K-series, manual bolts instead of the 19mm-head ARP bolts. I don't even want a professional machinist to do relief cuts. And lots of red Loctite because it is this or bust. This option is probably a potential contributing factor, but the next one is most likely.

3. The next part could be my bad. I machined reliefs in the flywheel to accommodate these bolts. When I went to install them, they didn't fit, and that was a surprise because they are designed for the K20, but the head is 19mm vs 17mm, and that extra width was enough to require clearance. I considered reselling or just taking a hit on the ARP bolt purchase and purchase K20 bolts, but then the timeline, so instead, I cut reliefs into the flywheel. My machining was amateur; it required some minor sanding to fix some blemishes, and I had really tight tolerances for the socket on a few spots. Who knows if the torque wrench was binding or the surface tolerance was slightly tilted. This is probably the cause, and it is me trying to get things done fast in the short timeframe I had with limited time for parts delays. Expensive mistake, but these are the lessons of life.

I will call Kpower tomorrow and see what the timeline will be on the flywheel. Crossing fingers. K-series bolts will come in on Saturday, so no long waits there.

PS: Removing the tranny with the engine still in the car is possible, but the tolerances are super tight. It took a lot of persuasion that would make it dam near impossible to put it back, but I ended up cutting some more of the passenger side mount. I removed probably a centimeter off the edge, and that should be enough, but I may need to do the same on the other side. The good thing is the transmission is suspended decently well by the driveshaft and engine, which doesn't tilt like the FA20, and what's more, the transmission mounts really don't feel like they need a whole lot of structure to feel very firm still. I'm not anticipating any problems, but you all know me, so maybe I'll eat my words.

[captain awesome]

Sorry to hear about your troubles. Hope you get it all sorted and get to see your true power potential.

[Irace86.2.0]

Originally Posted by captain awesome

Sorry to hear about your troubles. Hope you get it all sorted and get to see your true power potential.

Flywheel shipped. Should be in next week. I’m going for 400whp and 300wtq, I’m guessing around 10psi. Should be far away from the max potential of the turbo and hp. Should be away from the max on the engine too for stock internals. Less boost for more power with the turbo and extra displacement than the FA20 and the supercharger, but a supercharger on this platform would be cool too for sub-maximal power like I’m doing with this turbo/boost level.

[captain awesome]

Originally Posted by Irace86.2.0

Flywheel shipped. Should be in next week. I’m going for 400whp and 300wtq, I’m guessing around 10psi. Should be far away from the max potential of the turbo and hp. Should be away from the max on the engine too for stock internals. Less boost for more power with the turbo and extra displacement than the FA20 and the supercharger, but a supercharger on this platform would be cool too for sub-maximal power like I’m doing with this turbo/boost level.

That will be a nice power figure. Being able to stretch your legs with gears will be nice as well I assume.