Great work, Zak! Bad lines or not a lowly miata badgering GT350's is got tier. Great work! The cars you are competing with in that class is hilarious. Vette, gt350, MIATA. lol.

Also not sure if those are standard mustang GTs but we had a guy tracking one and it's fast. It's hard on consumables but the traction, braking, and laptimes all impressed me when I went for a ride along.

 

Heh, this made me curious so I had to go look up your and the GT350 TT3 forms in the compliance database. Now I'm wondering -- what's the -0.3 for "Modification of the OEM roof line/shape and/or windshield/frame removal"? Aftermarket hardtop?

Do you know if the 449 on the GT350 is detuned? For some reason I thought they were closer to 500 at the wheels.

BTW, are you planning on going to BW in April? I'm leaning strongly towards coming down for that one.

--Ian

 

Yo, thanks Nate! Yeah, admittedly I didn't really watch the footage beforehand. Guess I was so excited while driving that I didn't notice the car ahead was kinda all over the place on that lap. Their PB ended up being over a second faster in the video, so I think (hope) that they were all over the place because I was in their mirror lol. Regardless, don't care too much. Still a rush fighting for times all weekend haha.

Ian, I added the roofline modification factor due to the makeshift dovetail I added to the car. To be honest, I don't know if it actually qualifies for the modifier. I also don't think anyone would call me out if I didn't claim it, but I figured it'd be best to play it safe.

I'll have to ask her next event if the car's detuned. Never considered that. They make an advertised 526 horsepower at the crank stock for what that's worth, but the powerband is pretty peaky if I remember correctly, so that might bring the "average" whp figure down quite a bit for classification.

I'm in a weird spot with the car classification-wise already. I'm currently ~40whp under my max power limit. Tire classification rules for this year allow for more power in my tire class than last year. I'm running the car at about 300whp and it's doing fine, but I fear bumping power above 320 will take me into the danger zone for the stock trans and bottom end. If I were to build a forged motor and do a trans swap on this thing, I could probably get within spitting distance of 1st place, but I don't feel like the (very expensive) juice is worth the squeeze at the moment.

I'll 100% be at Buttonwillow in April. Signed up last week actually. It would be awesome to finally match a face to the name!

 

100% leave the car as-is or detune it for a different class if you wanted to go that route, imo! You've already thrashed 1 NC box and you are at a sweet spot stock motor and trans wise. If anything start looking for more weight reduction, I'm not sure what more you can do really, or how far down the racecar hole you wanna go even in that regard.

The car really is a sweet package right now and building cars for rulebooks can be frustrating when those rules change, or you just want to race with a different group.

Again, love what you are doing here and it still makes me want an NC

 

Oh yeah, the TT3 class endgame for this car isn't going anywhere haha. Our region's biggest classes are TT5 and TT3, and I certainly don't want to dish out the cash to run a car higher than TT3 class haha. TT4 would be a super fun class to race in (my max power limit would be around 250whp with current tires unless I added some ballast). Just aren't that many cars in class usually. We had 4 in TT4 this weekend and that's more than usual. At any rate, I'm going to keep the car as is for the long haul aside from gearing changes and some additional aero.

Housekeeping.

Started the week by swapping my street tires and pads back in. Found this in one of my rear tires. Could've picked it up driving back into my neighborhood or before the first session on Saturday lol. Bummer. Tire was still holding air, though. I patched the tire Tuesday as this set will likely be retired and used for street use.



The brake ducts seem to have done their job. Recently, I've been pulling my DTC60 pads out after a race weekend and going "Damn, that much wear in two days!?" I was running shorter sessions this weekend due to the heat, but these pads basically look the same as when I put them in last week. I'll measure them for a before and after test at the next event.



Rotors are kind of another story. These have four days on them and are still getting some decent spider-webbing. I think it's less so than before. Usually after five days, the rotors would show cracks all the way to the edge and be ready for replacement. These might have two days left? Will have to see how long a fresh pair lasts with the ducts. Also only the outside face is showing stress fractures.





I've been playing around with ideas for a turbo brace for a bit now. There aren't really many options to brace the turbine housing to the head or block as it sits on top of the manifold and space is tight. Making a brace from the block to one of the oil drain bolts would be nigh impossible, but I have a couple M10 threaded holes in the head that are currently unused. I cut up a cat converter bracket I had from a Bronco Sport, along with some random steel plate I had laying around, and mocked up a brace that would bolt the turbo to the head via the V-band stud. I think this is normally a no-no right? The bracket is thicker/stiffer than it looks and can't be flexed at all without tools. Don't know if it'd be stiff enough to take all the load off the v-band but I figured something like this would be cheap insurance to keep the turbo in place if the V-band fails. Thoughts? I haven't bolted it in yet as I'm waiting for some fine thread nuts with larger faces to arrive.

 

I'm not sure how I feel about that, to be honest. I'm not sure bracing the turbo at the vband is the right move since it already broke there once before. It could help, or make it worse, or nothing at all! Not that this helps you any, just starting the discussion.

 

Yo! Hell yeah, always appreciate you chiming in Nate. I?m mostly questioning whether bracing the turbo via the downpipe V-band is a good idea or not just due to putting additional stress on that v-band stud itself. FWIW, it?s that lower V-band connecting the turbo to the manifold that I?ve been having issues with. Figured having the upper brace might take some of the leverage off it.

Gonna have to play with it more next week. Have spent a lot of recent weekends in a row doing car stuff. Gonna switch it up and head north to Santa Cruz this weekend to ride mountain bikes with the boys

 

Can you support the turbo on the cold side? Lots of bolts there.

 

I've tried to picture some different ways to use the compressor housing bolts for bracing but I can't figure out any options that seem like they'd be stout enough. The only option that looks like it might work would be making a brace from the top compressor bolts to somewhere on the valve cover. Using the lower bolts seems like it'd be near impossible since you'd have to work around the manifold runners. I'll post some more detailed pics next week and see if anyone has some clever ideas.

 

I am not an engineer, nor am I very smart, and this was on a Volvo racecar, but I believe one of the reasons I had so many broken studs and hotside housings is the difference in heat expansion rates between the cast iron housings/ stainless wastegates and the hardware holding it together. I finally solved wastegate stud failures by matching stainless studs to my ATP stainless wastegate housing. Inconel was the only thing that would last between manifold and hotside, so i suspect the lack of expansion of the inconel eventually stressed the hot side flange causing failures.

I don't know if this speculation hurts or helps you. Racing is expensive and breaks everything.

 

I see, I forgot which V band you had broken on that thing. Makes sense that it's the inlet one.

I still think that's more likely to break your V band than anything else, but send it and see what happens! I know @emilio700 was playing with some turbo bracing using swaybar endlinks, but those were lower down and actually connected to the hotside of the turbo itself, IIRC. No idea if that was successful for them or not though.

 

I’m gonna get stickers of this made and slap ten of them on my car.

That’s actually great insight because I hadn’t considered the rate of expansion between the materials at play. Not much I can do about it, though since the turbine inlet and outlet are both v bands. I’ve seen companies that make stainless housings for this turbo but I still think the issue lies in it being a top mount with the turbo sitting at a slight angle on the manifold and only one v-band holding it on.

Veru small development but I realized today that the car converter outlet V-bands on those same Bronco Sports are 2.5” and look a bit more stout than your typical v-bands we’re used to seeing on here. Instead of the clamping surface being split into three sections, the entire circumference of the flanges is clamped down on and the clamp looks a little thicker overall. Gonna slap one on next week and see if it works, then bolt up the brace I made and see if that breaks as well.



Ignore the integrated gasket, that’ll get tossed.

 

Ended up pulling the turbo off last week and tried to use one of the above v-bands to hold the manifold on. Unfortunately the Ford v-band didn't end up being a viable replacement. The profile of the clamp was a little too wide/broad for the manifold and turbine flanges and didn't exert any clamping force when torqued all the way down. Oh well, it was worth a shot. Fortunately, I ordered some other standard clamps to try out and found some 2.5" quick release units that seem to clamp more surface than the clamps I've been using. Hopefully that helps.

So I figured out why my car started running lean at WSIR a couple weekends ago.



Ok, that didn't all happen at once, but it turns out this has been brewing for a while. I drove the car to work on Monday and found it running lean at idle and low-load again despite having upped the MAF scaling at WSIR. I've been getting some intermittent smoke out of the tailpipe at idle after warmup (suspect it's my turbo drain having too many twists and turns), and noticed that I was getting a little smoke out of my hood vents now too. Pulled the car into work and sure enough, I had an exhaust leak coming from the front of the downpipe inlet flange, just ahead of the O2 sensors. It was cracked about 120* around the front of the pipe.



Since I had some other things I wanted to do to the car this week, I slapped some extreme temp JB weld into and around the crack Monday night, and drove it to work yesterday to get some things done on it. I figured the downpipe brace was probably exerting some sort of force on the downpipe, and I could readjust that and drive the car as-is this weekend before removing the pipe and getting it re-welded next week. This morning, some buddies and I hit the mountains and I got a couple good runs in until the exhaust suddenly got way louder and the O2 sensor pegged full lean. Yep, she's cracked. I unplugged the ECU's O2 sensor to keep it from dumping extra fuel into the mixture, then headed home and removed the downpipe once the car cooled off.



To my surprise, the downpipe brace wasn't excessively preloading the pipe in any direction. Upon disconnecting the rest of the exhaust from the downpipe outlet, I found the smoking gun. I've got hose clamps on all of my exhaust hangers, and the preload from those was yanking the entire exhaust towards the back of the car, which would explain the front of the downpipe being the first area to give out. After disconnecting the downpipe outlet, the rest of the exhaust came to rest about a full inch back from where it had sat, and forcing it forward to seat against the downpipe was nearly impossible. Haha, oops. Won't be doing that again. I removed all the hose clamps from the exhaust hangers and will readjust it when I reinstall the downpipe to make sure the same thing doesn't happen again.

In slightly more fun news, I finally grabbed a set of splitter tunnels for this thing.



These came from a random eBay seller, who noted that they ship in two pieces. Of course, I didn't read that part and was very confused and a little disgruntled when they showed up as such. Neither of the front and rear tunnel pieces quite perfectly matched each others' shape as well. Luckily, I just got an air fryer at home, which worked wonderfully to soften the pieces up and get them aligned perfectly. Probably still worth paying less than half for these compared to the $250 Racebred ones, or some of the even more expensive options out there. I saw a carbon set listed somewhere for $650. Don't care how much benefit those provide, I'm not paying anywhere close to that just based on principle alone lol.

Now that I'm typing this, I seem to remember a couple of you offering to 3D print a set of these for cheap. I should've gone back and sent out some PM's. Oops.



I took the measurements on these guys and they've got a slope of 10*. Occam's Racer said something about not wanting to exceed 12*, so that's good enough for me. Science.



ProfessionalAwesomeRacing splitter rods were on a 4-6 week backorder so I grabbed some splitter cables from BuildJournal to add additional support. This was probably overdue even if I weren't adding the tunnels. The sides of this splitter were never very well-supported. Thing's way way more sturdy with the rods bolted in.



Tunnels installed with some standard 2-part epoxy and a bunch of small screws. Not pictured: I took an angle grinder to all of the screws on the leading edge to try and lower their profile.

The RC1's I ran for the first two NASA weekends are actually still looking pretty good. Probably because I was running short sessions at WSIR. I'm still swapping to a new set for Buttonwillow in two weeks and will be retiring these to be used as "fun" trackday tires.



Aside from the exhaust debacle, I think we're mostly ready for Buttonwillow in two weeks. I'm trying to work a corner balance into the schedule, and I still need to get my blown NC1 6 speed rebuilt with the upgraded NC2 4th gear clutch hub and fork. Unfortunately, as expected, I'm still just trying to dial in remedies for all these minor annoying teething issues. I'm making progress, though.

Went over to my parents' place yesterday to help my dad with one of his motorcycles, and he remarked that every bike he built (recreationally) required about a year's worth of combing out teething issues. Made me feel a little better about the project. Again, I don't really need any more speed out of the car at the moment, and none of the issues that need rectifying have been catastrophic. Guess I'm just looking forward to having everything dialed in so I can focus on setup and optimization like last year. As it sits, I haven't played with any suspension settings in almost six months haha.

 

Killer updates as always man, you are a madman.

I have a set of professional awesome splitter supports if sell ya, If you want em. Never used.

 

Not sure if it would be cost effective or if my mediocre 3d print fab stuff would hold up, but I'd always be happy to print some of those pieces if you want.

Bummer on the v-band stuff. Hopefully you've got that issue solved now, but moving to V bands always seemed like a no-brainer now that I've used them. Granted, I'm not sure if traditional 2/3bolt exhaust flanges would've solved the issue. I'd think those would be stronger overall, but I digress...

 

Thanks Nate! Dang, I should've posted a message first seeing if anyone had a set on hand haha. I think I'm good with the cables for now, but I might hit you up if I end up needing more support for the ends after the next race weekend.

Sim, that'd be awesome if you're willing to try. I'll hit you up if I smash or tear one of the tunnels off the car!

Yeah, the V-band issue is kinda weird to me too. After spending a bunch of time trying to rectify it, though, it sorta makes sense to me. The flange is just so much smaller and has more leverage acting on it than say a standard 4-bolt T25 flange. There's no other option that would fit the current hotside layout, though. Space in the area is really tight and a v-band flange is all that would fit without raising the turbo higher I think. If I can just make something to effectively support the turbo from the top, the v-band issue should subside. Really looking forward to seeing if my brace to the head has a positive impact in two weekends.

 

Got the lower downpipe welded on Monday and we're back in business. Welder took one look at it and said he could make it sturdier no problem. Got it installed on Tuesday and retuned everything accordingly, pulled about 5% out of the MAF tables and made some small 1-2% changes at idle and cruise to get trims nearly to zero again. The thing must have been cracked for a while, the car's noticeably quieter than I remember it being.



I need to learn how to weld. It'd make things so much easier.

I also need to get off the forums/FB groups. One of the shops on the NC Facebook groups posted a teaser of their upcoming 8HP-swapped turbo NC build and it sent me on an insane 8HP-swap deep dive this week. My timeframe isn't immediate. If I do it, it won't be until the end of our race season, so I have some time to take the car out of commission. Probably after Global Time Attack in November. I could do it over summer too as there aren't any races between late July and October... but I know I should probably chill and slow things down a bit rather than do that.

Ended up messaging a bunch of guys on FB who have done NC 8HP45 swaps and have been actively posting. Promising findings:
-Yes, the 8HP45 from a 2015-2017 Jaguar XE 2.0L (EcoBoost) bolts straight into an MZR/Duratec. So do the flex plate and starter.
-There's ten of these Jag transmissions within an hour and a half of me listed between $175 and $300.
-You've got a few options for TCU's. MaxxECU, CANTCU, and Turbolamik. Turbolamik already has support for the OEM NC ECU, negating the need to run a standalone with CANTCU, or run a MAXXECU. Can/should/will I go standalone at some point? Absolutely, but the factory ECU isn't a huge limiting factor for me currently. Not having to wire up and tune a whole new ECU makes this project a whole lot more palatable, and will allow for more time spent diagnosing whatever I run into/f*ck up with the transmission swap.
-There are more than a couple guys already running these on a stock ECU/Turbolamik, and a few builds out there running various versions of trans/diff mounts. Some have modified and retained the PPF, others have made standard trans and diff mounts. I haven't heard one report of driveline vibrations (cue PTSD episode from my Kpower ZF6 swap).
-Despite the 450nm (332lb/ft) input torque rating, firsthand accounts say these transmissions are seriously underrated.







I'm gonna get off the internet for a bit before I start getting/executing bad ideas.

 

Absolute game changer. If you can cut and meld mettle, a whooole world of possibilities open up to you, one that's not rivaled, imo, untill you get into CAD and 3D printing.
Let's be honest... we all saw this coming. Welcome to the dark side of 8HP transmissions. Bad ideas are welcome, and the shifts are lightning.

 

Thanks for the help yesterday prepping the car for Thunderhill.

I have a harbor freight flux core welder collecting dust in my garage you can borrow to practice on if you want. I would probably never ask for it back.

I also have a China MIG if you ever need to use it.

I do need to take some lessons on the MIG. My welds are ugly.

 

Very interested to follow your progress with the 8HP. Having driven a couple of really good paddle shifted transmissions on track, it's a game changer. The amount of driver workload freed up to apply to corner entry/exit is not insignificant.

And +1 on welding. With YT these days, and a few hours practice it's easy to be making good welds in no time. I bought a little Lincoln 220 MIG almost 30 years ago and it's been one of the best tool investments I ever made. These days there are a lot of pretty good welders for not a lot of money. My recommendation is just go for a welder with gas right from the start. 220 is better if you have it available, but 110 will get the job done for most projects.