Yellow Jacket Gets A Turbo!

[Yellow Jacket 26]

I want to say thanks to Mike and Micah at OST for making Challengerfest 7 the best ever for me! It all started a year ago, at the end of CF6 when I decided that I wanted to upgrade my engine from the stock block. I had been working with Mike for a couple years tuning the Procharger, but I was really impressed by what his Jeep was doing with the HRH engine and big turbo. After much discussion, we decided on the HRH engine, turbo, clutch, driveshaft, differential, axles, 15” conversion, triple pump return fuel system, and racing suspension with a plan to have the car ready to start testing in the Fall.

Micah is handling what I consider to be the REAL build thread, with detailed technical explanations and lots of pics. This is the story from my (not-very-technical) point of view.

Parts delays held up the engine, but it was installed and fired up the first week in October. Then we got hit with the now-infamous reluctor wheel problem (which you still can’t mention around Mike without him cringing). That cost us a few months worth of delays, but meanwhile they kept plugging away at non-motor items (roll bar, clutch, drivetrain, 15” conversion). Even if there was nothing to report, Mike or Micah always contacted me to let me know how it was going. The engine came back out the last week of December, then went back in with the stock reluctor wheel from my old engine at the end of January. After that, Micah went full-bore on the turbo system, and fired up the car exactly one month before Challengerfest 7. Not counting the delays from parts, the build took about 8 weeks. With big things done, but still a giant list to-do list, they went into “triage mode” and focused only on the things necessary to get the car onto the track in time.

I showed up on Tuesday before Challengerfest weekend, and there was my beloved Yellow Jacket that I had not seen in several months, all washed, waxed, polished and ready to go. I hadn’t realized until just then how much I missed my car!

Mike took me for a ride in it first, to show me what to expect when the power comes on. It was pretty insane. My street tires are the Continental Extreme Contact DWS, which are great all-season tires, but not so great 1000+ HP tires. We were breaking loose in all gears before he could really show me how the car could pull.

When they handed the keys to me, I was fearful. I had seen both Mike and Micah drive it, both more experienced drivers than me, who BUILT the damn thing, and they were taking some effort to control it. I was pretty tentative, and even stalled it a few times (they were nice and said something about it not being as driveable because they hadn’t worked on the street tune, but still). And I was seriously going to take this thing down the track in 3 days?

The next day we finished up some things around the shop, and I drove it a little more on the street. Both of them sensed my uneasiness because each of them had separately asked me at different times if everything was alright. I think they feared I wasn’t happy with the build. In fact, just the opposite. The car was everything I had hoped for and more. So much so, that it made me anxious as all hell, wondering if I’d be up to the task of driving this thing down the track, keeping it and myself in one piece. I had grown comfortable with the Procharger and stock block combo, having driven it for 3 years. That was familiar to me. This new car, a magnificent machine so powerful and so strange might be too much to handle. I feared that I might not be worthy of it, that maybe I had bitten off more than I could chew. Maybe I had made a mistake with this whole “big build” thing. Yet there was no going back. My old stock block had already been turned into the prize to be won at CF7. My Procharger had been sold to somebody else. Even my old Getrag and driveshaft belonged to the Sprintex car. My old familiar friend had already been torn into countless pieces and scattered across all of Mopardom, never to be seen by me again. I could only plunge forward. So I put on a brave face and told them that I was a little nervous about driving it. They were very supportive and reassuring.

On Friday I was going to take the car for a few easy passes, get used to rowing through the gears down the track. I stalled the thing right after the burnout box, and I think it was my nerves that made me forget the whole “take it easy” idea, because once I launched it, I just wailed into it all the way down the track. So much so, that I lost traction in all 4 gears. Almost gave Mike a heart attack, because he thought I was going to go sideways.

When I came back, Mike said, “What was THAT? I thought we were going to go easy?” I felt bad, but I had just gotten so excited being out there, and there was the car in the other lane that I just HAD to chase down. Mike was understanding, thankfully, so the second pass we decided to try a couple speed shifts. But the car got squirrely on that one too, and with the cold weather and lack of track prep, we decided to pack it up and save it for Saturday’s racing. Good thing too, because right after that decision it started to hail.

That night I slept well. I was no longer scared. I was relieved, happy, and confident. I felt that maybe I could do this after all, and so Saturday I would really focus on getting them the data that they needed. I started out the day with a 12-second pass, followed by an 11.5, and then an 11.4, a personal best for me. I was learning the car, and speed-shifting most shifts. My timing was way off, though, and I probably hit the rev limiter about half the time. The real trouble started when I raced Murray in the 6-speed shootout and couldn’t make the 3-4 shift due to grinding.

I took it out again to see if it was me or the car, and sure enough the car wouldn’t go into 4th, it would just grind. Mike knew what the problem was even before I got back to the pits. I had red-lighted at the start of the pass which should NOT have happened with the clutch fully engaged at the light. The car was creeping forward (I don’t use the line lock on launch).

To eliminate the possibility that it was my driving, I asked Micah to take it down the track. When he did, he confirmed the same thing happened, but that time in the 2-3 shifts as well as the 3-4 shifts. We did one final test back in the pits. We revved the car to 4,000 RPM in gear with the clutch on the floor, and sure enough it was creeping forward ever so slightly. It’s a McCleod clutch, but one that they make for the Viper. To fit the Challenger, they custom made a flywheel for us. Micah was on the phone with them constantly, checked the air gap and put it together with the specs McCleod gave him. He tested it by lifting the rear, putting it in gear, engaging the clutch and checking for wheel spin on throttle. No spin. Everything seemed fine, and it even passed speed-shifting tests both on the dyno and the street. Still, there is no test like taking it down the track. We think the clutch is heating up, causing expansion that prevents full disengagement. We need to shim it.

Those of you who saw my runs or the videos know that I took the term “shake-down” passes literally. Micah said my burnouts looked like a video game where they exaggerate the shaking, rumbling and smoke for dramatic effect. Aside from the clutch, the car performed flawlessly. All the electronics worked as they should have, the engine was making great power (when I had traction), the turbo sounded awesome as all get-out. IATs at the top end never left double digits. Nothing leaked, nothing fell apart. We never turned a wrench on the car the entire weekend. Everything held together despite my attempts to the contrary. Here are the videos of me trying to destroy the car from the get-go: http://modernmoparforum.com/topic/17480-ost-dynos-1000whp-turbo-challenger-build/?p=449517

I was really hoping I wouldn’t break the car this weekend because I was so looking forward to driving it again! My wish came true. Even though there are a few minor things left in the build, Mike’s letting me take it to enjoy it for a while. Get some street time, get comfortable with it. The intent all along was to make a 1,000+ HP daily driver, so now I get to sort out the daily driving part. Any issues that crop up will go onto the “Phase 2” list, and when I’m ready I’ll let it go once again to OST for completion. Well, completion of Phase 2, because there will probably be a Phase 3, and so on.

If I wanted easy, I would have bought a Hellcat. I didn’t want easy, I wanted different. I wanted something special, something unique, something nobody else has (or maybe even wants). I wanted to learn things, which I did. I’m really grateful to OST for giving me all of that, my kick-ass 1000+HP Yellow Jacket. A car that may frustrate me at times, teach me at other times, and challenge me most of the time. Thanks guys, for being there every step of the way, and for taking me on this awesome journey!

[BayouTigress 73]

Cool story Howie! And builds at your level will take a bit of work to be comfortable driving. I know ours did and you have 300+hp on Gossamer. It takes seat time and figuring out the quirks. And being comfortable with those quirks. I bet yours will be a kick to drive on the street. My one caution, high hp on the street does not mix well with cold or wet streets. But Chuck, and Phil, and Sam, and Kenny, and Sean, and Eric, and Dale, Jack, Mike H will all tell you that may be my fault for treating the gas and break pedals like digital devices.

[jettech104 27]

Congrats Howie on your new beast. Happy to see you make those passes with no prior seat time. That took some big cajones my friend. Enjoy her and you will get use to her in no time.

[Hemi57 51]

“triage mode"...fix the important shit first!

One hell of build Howie...

OST - FTW

[StevoHemi 113]

Great build and great story Howie. I have seen all the videos. Car is a nasty beast!

Looking forward to Phase 2! Keep us posted.

Congrats to team OST for a great build!

Stevo

[Yellow Jacket 26]

Cool story Howie! And builds at your level will take a bit of work to be comfortable driving. I know ours did and you have 300+hp on Gossamer. It takes seat time and figuring out the quirks. And being comfortable with those quirks. I bet yours will be a kick to drive on the street. My one caution, high hp on the street does not mix well with cold or wet streets. But Chuck, and Phil, and Sam, and Kenny, and Sean, and Eric, and Dale, Jack, Mike H will all tell you that may be my fault for treating the gas and break pedals like digital devices.

Thanks Lisa! I wanted to drive it so badly yesterday, but refrained because it was raining all day. Micah said that was "wise." Haha! So today was my first full day out with it, running errands. The thing turns heads with its sound alone.

Congrats Howie on your new beast. Happy to see you make those passes with no prior seat time. That took some big cajones my friend. Enjoy her and you will get use to her in no time.

Thanks Eddie! It was great seeing you (and racing you) this year. Let's line up again at CF8!

“triage mode"...fix the important shit first!

One hell of build Howie...

OST - FTW

Thanks Dale. And yeah, OST rocks. I could not BELIEVE they got this thing on the track in time. And I think Mike could not believe I didn't ball it up this past weekend. .

Great build and great story Howie. I have seen all the videos. Car is a nasty beast!

Looking forward to Phase 2! Keep us posted.

Congrats to team OST for a great build!

Stevo

For sure Stevo. It's a process and a fun journey. A friend of mine said that "therapy would have been cheaper." I told him maybe so, but not nearly as much fun.

[BuckeyeGuy 82]

Howie, great to see you again and your car is a beast! Congrats - have fun with it and above all, treat it with respect.

[Yellow Jacket 26]

Thanks Guy! Definitely lots of respect for the car. It was great to see you this past weekend as well. I need to make some MSHS events, because seeing my Mopar friends just once a year doesn't seem to be enough.

[DevilDogge 23]

Awesome, Howie. I had no idea you were stepping up your game to that extent! Glad to see you sticking with the 6 speed. We're on the verge of yanking ours and sending it to RPM for a upgrade. Congrats, man!

[Yellow Jacket 26]

Thanks Tim! I would hold off on that RPM option for now. Take a look at what Mani is doing, because he might have found a better solution. We're keeping an eye on that one.

And they can yank the shifter out of my cold dead hands before I become a burrito eater!

Sent from my iPad using Tapatalk

[muzza61 60]

Good stuff Howie. Great write up. Keep us posted on your 4th issue and if the shim fixes it.

[Yellow Jacket 26]

Will do, Murray! We stubborn 6-speeders gotta stick together. I'm very interested in seeing what Mani has to report after inspecting his transmission. It would be good news to see it survive multiple back to back 10-second passes.

Sent from my XT1096 using Tapatalk

[toofart 148]

Cool story, Howie. I'm pissed that I missed this at CF, since you had given me hints ahead of time that you had something up your sleeve.

The fact your shit didn't break is a great testimony to the work performed by OST. Just make sure Alan doesn't go anywhere near it

I hope you can make fall VMP. I'll certainly be there, so we can show those pegleg burrito eaters how real men drive

[Yellow Jacket 26]

Thanks Denis. You were missed, for sure. I don't know if Fall is enough time for me to learn to drive it properly, but if I can make it I will! It would be great to see you again if nothing else.

And good point about Alan! Maybe he needs to be quarantined at these events, or at least not allowed to go within 10 feet of anyone's car.

[Speedy 247]

Great story Howie. Did you type right that it realistically took about 8 weeks to get this car together? I know there was some waiting on parts and the reluctor wheel hold up, which I know was time consuming, but without that 8 weeks? That's kick ass right there. I think some folks avoid doing builds due to the time they think it will take, and your car was VERY nicely engineered and executed. The factory look was just amazing as I've told Micah. Something I go for on my projects, "if the factory had done this......" mantra.

Your trans held up and other than the clutch you didn't have a single issue. Those McLeod clutches are starting to make me scratch my head. Mine did the same thing yours is doing and required changes. Murray's is doing it now too. Makes me wonder if they're not taking proper measures somewhere, or underestimating how much their clutch parts expand under heat and RPM. A shim is an easy fix.

You were at 750ish RWHP this weekend correct? I think other than Sam you're putting the most through a RPM trans. So far so good.

I think guy hit the nail in the head with respecting the car. Get you some 555R 305/35 R20s on the rear and I think you'll have a safer car to drive, although the tires won't last as long. Well worth it though.

Congrats on a bad ass ride.

[El Diablo 72]

Build turned out bad ass Howie ! Hell of a debut for such a build.

So how much air gap on the throw out bearing did they start with ?

[SmallBlockMuscle 6]

Is any creep normal when revving to 5k or so with the clutch pushed in? I just put in a McLeod as well. There is a slight turn with the rear wheels in the air and revving it to 5k. On the ground it barely moves but I think it does a little.

[El Diablo 72]

Is any creep normal when revving to 5k or so with the clutch pushed in? I just put in a McLeod as well. There is a slight turn with the rear wheels in the air and revving it to 5k. On the ground it barely moves but I think it does a little.

More than likely as the disc breaks in and gets seated it will get worse, insufficient air gap. As everything heats up the air gap closes up even more and compounds the problem.

[Yellow Jacket 26]

Build turned out bad ass Howie ! Hell of a debut for such a build.

So how much air gap on the throw out bearing did they start with ?

Thanks Kenny! I have no idea on the air gap, you'll have to ask Micah. He and Mike were talking about it though, and I thought I heard him say it was too much. I'm not sure if we're thinking about the same air gap, because Micah said he should CLOSE the air gap, not widen it to accommodate expansion.

Is any creep normal when revving to 5k or so with the clutch pushed in? I just put in a McLeod as well. There is a slight turn with the rear wheels in the air and revving it to 5k. On the ground it barely moves but I think it does a little.

No, it is not normal. That's how Mike realized something was wrong with the clutch, when I redlighted by creeping forward at the lights with the clutch fully depressed and revving to 4,000 rpm. A lot of people launch with line lock, which would completely hide this effect, but I don't.

[El Diablo 72]

Thanks Kenny! I have no idea on the air gap, you'll have to ask Micah. He and Mike were talking about it though, and I thought I heard him say it was too much. I'm not sure if we're thinking about the same air gap, because Micah said he should CLOSE the air gap, not widen it to accommodate expansion.

You are correct, Been a long dayyyy ! If the air gap is to much it's not fully compressing the pressure plate which won't release the clutch disc.

But on the same hand you have to be careful not to close it up to much either because when everything expands it can compress the pressure plate to much and damage it.

No, it is not normal. That's how Mike realized something was wrong with the clutch, when I redlighted by creeping forward at the lights with the clutch fully depressed and revving to 4,000 rpm. A lot of people launch with line lock, which would completely hide this effect, but I don't.

[Yellow Jacket 26]

Great story Howie. Did you type right that it realistically took about 8 weeks to get this car together? I know there was some waiting on parts and the reluctor wheel hold up, which I know was time consuming, but without that 8 weeks? That's kick ass right there. I think some folks avoid doing builds due to the time they think it will take, and your car was VERY nicely engineered and executed. The factory look was just amazing as I've told Micah. Something I go for on my projects, "if the factory had done this......" mantra.

Your trans held up and other than the clutch you didn't have a single issue. Those McLeod clutches are starting to make me scratch my head. Mine did the same thing yours is doing and required changes. Murray's is doing it now too. Makes me wonder if they're not taking proper measures somewhere, or underestimating how much their clutch parts expand under heat and RPM. A shim is an easy fix.

You were at 750ish RWHP this weekend correct? I think other than Sam you're putting the most through a RPM trans. So far so good.

I think guy hit the nail in the head with respecting the car. Get you some 555R 305/35 R20s on the rear and I think you'll have a safer car to drive, although the tires won't last as long. Well worth it though.

Congrats on a bad ass ride.

Thanks Speedy! Yeah, it was just about 8 weeks of total build time. If you start counting from second engine install, turbo fabrication, and a bunch of other stuff. Micah did the roll bar, drive train, and 15" conversion before the engine trouble happened, but that could have been done within the 8 weeks where we were still waiting for stuff. So I can confidently say that if you lock Micah in his shop with a stock Yellow Jacket and all the parts, 8 weeks later he'll emerge with my build. Actually, sooner because he's done it once already. He works fast, but I think more importantly he spent a lot of effort researching, thinking, and planning before executing. That's the key right there. For instance, before he even started putting the turbo system in, he made diagrams, mocked it up on another engine they had, as well as the Sprintex car (which actually didn't work out so well due to a difference in the motor mounts), and still had to make changes on the fly.

We were actually running at the full 1000+ HP this weekend. That 750 number was from the initial dyno runs when we were at about 1.5 psi and testing for leaks. Running off the wastegate, which we were this weekend, generates about 10 psi and the full 1000+ HP. We're thinking of going with smaller springs and about 7 psi for the next track session, but I don't know. I would rather learn to drive it in this triple-digit HP configuration.

I've ordered my Nitto 555Rs, with the matching 555 G2's for the front. But I only have 9" rims, so I had to get the 275/40/20's on the back, and 245/45/20's for the front.

[Micah@OST 13]

Thank you all for the kind words and compliments. I really do appreciate it and it means a lot! As I told Howie, fabrication is my true passion. So again, thank you all!

[Hemi57 51]

Micah you have very bright future ahead of you. Your dad should be mighty proud of you.

[ostmike 35]

Micah you have very bright future ahead of you. Your dad should be mighty proud of you.

He is smiling ear to ear - and so is my wonderful wife!

[turbofreek 27]

awesome story. aint no pull like a turbo pulling as you upshift it just pulls harder. loved my old manual trans turbo v8 car back in the day. total blast to drive.