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Trying to reignite this thread. It seems appropriate, given that it is now in a Frankencar, and we’ve had to follow up on some hard-win lessons and trailblazing done by Doc.

If I screw up any of the technical issues, please defer to Skip’s version of events and knowledge if he chooses to post.

Quick Gist/BLUF: I ended up drooling over this thread when Doc was getting this build done. So I ended up calling Skip and putting some things together one winter on a smaller project, and it spiraled. Was just going to upgrade from a 2.8L KB on a short block that hadn’t been built yet. Mission creep took hold.

I now have this transmission, and thanks to the work that Skip and Doc put in, a similar project has taken shape- twin turbo car with a built engine. If you’re familiar with the Demon/TKM engine line, this would probably be considered “capable.”

Latest issues solved- getting a clutch for this that will handle the maximum power. If you’ve seen the IG page, that RPS quad carbon clutch is going on this. The ancillary issue was getting the right clutch slave fitted up- took a lot of shop time to get it fitted, and ended up with some machining being done on a Tilton to get one to fit to spec.

The picture above is some of Nate’s work in progress- having two sets of pipes for this on v-clamps. The one above is the drag/track pipe that is getting cutouts. The other one, because of emissions and inspection requirements, will be a cat pipe essentially being run at wastegate pressure for the street. I would never simply run the track setup outside of those conditions, and how dare anyone think or imply that 🤣

It’s been a long road, and it’s not done yet. But we are starting to get much closer to this thing hitting a dyno finally, and it couldn’t have happened without Doc stepping up on it as a trailblazer in the first place. A ridiculous amount of custom-now-production and one-off pieces came out of this, but hopefully the roadmap has been finally finished out for the project for future development/implementation for those looking to go this route.

I am pleased to share that we have specified this with a pair of PTE 7275 turbos, and a 3.40 pro out back. For those that implicitly understand what that will mean, the other uses for this will likely be on a road course- we are exploring another pumpkin for this to be swapped in that application and for general on-street use to prevent associated issues.

Why the timing now if the car isn’t quite done?
Well, a couple of reasons.

Skip and the guys have put up with me over the time period required to get this to this point, and it felt like they deserved a shout-out for one. Winter is coming, and that means build season for two. Finally, I’m preparing to exit the service, so this is attached by some manner to that time and timeframe, as date would have it. While that means it will likely sit for a lot of the winter… I will remain faithful to the experience of others over the course of it, as I hope this makes some serious passes at a number of events the next full season.

There are additional developments on the way, and I hope to be able to share those as well- I have a wrap ready to go on that may come out seriously hideous or not, but only time will tell and if I can help other people to avoid a potential mistake or get to see how something potentially cool turns out, great. Suffice to say, I have not seen it on the platform before, and I’m eager to see it after the execution.

In closing- games are afoot, and this did not occur in vain.

Soon.
 
Trying to reignite this thread. It seems appropriate, given that it is now in a Frankencar, and we’ve had to follow up on some hard-win lessons and trailblazing done by Doc.

If I screw up any of the technical issues, please defer to Skip’s version of events and knowledge if he chooses to post.

Quick Gist/BLUF: I ended up drooling over this thread when Doc was getting this build done. So I ended up calling Skip and putting some things together one winter on a smaller project, and it spiraled. Was just going to upgrade from a 2.8L KB on a short block that hadn’t been built yet. Mission creep took hold.

I now have this transmission, and thanks to the work that Skip and Doc put in, a similar project has taken shape- twin turbo car with a built engine. If you’re familiar with the Demon/TKM engine line, this would probably be considered “capable.”

Latest issues solved- getting a clutch for this that will handle the maximum power. If you’ve seen the IG page, that RPS quad carbon clutch is going on this. The ancillary issue was getting the right clutch slave fitted up- took a lot of shop time to get it fitted, and ended up with some machining being done on a Tilton to get one to fit to spec.

The picture above is some of Nate’s work in progress- having two sets of pipes for this on v-clamps. The one above is the drag/track pipe that is getting cutouts. The other one, because of emissions and inspection requirements, will be a cat pipe essentially being run at wastegate pressure for the street. I would never simply run the track setup outside of those conditions, and how dare anyone think or imply that 🤣

It’s been a long road, and it’s not done yet. But we are starting to get much closer to this thing hitting a dyno finally, and it couldn’t have happened without Doc stepping up on it as a trailblazer in the first place. A ridiculous amount of custom-now-production and one-off pieces came out of this, but hopefully the roadmap has been finally finished out for the project for future development/implementation for those looking to go this route.

I am pleased to share that we have specified this with a pair of PTE 7275 turbos, and a 3.40 pro out back. For those that implicitly understand what that will mean, the other uses for this will likely be on a road course- we are exploring another pumpkin for this to be swapped in that application and for general on-street use to prevent associated issues.

Why the timing now if the car isn’t quite done?
Well, a couple of reasons.

Skip and the guys have put up with me over the time period required to get this to this point, and it felt like they deserved a shout-out for one. Winter is coming, and that means build season for two. Finally, I’m preparing to exit the service, so this is attached by some manner to that time and timeframe, as date would have it. While that means it will likely sit for a lot of the winter… I will remain faithful to the experience of others over the course of it, as I hope this makes some serious passes at a number of events the next full season.

There are additional developments on the way, and I hope to be able to share those as well- I have a wrap ready to go on that may come out seriously hideous or not, but only time will tell and if I can help other people to avoid a potential mistake or get to see how something potentially cool turns out, great. Suffice to say, I have not seen it on the platform before, and I’m eager to see it after the execution.

In closing- games are afoot, and this did not occur in vain.

Soon.
Good stuff, and it only took me to "BLUF" before I was certain you served - the rest of the writing style only cemented that. Should be quite the machine.
 
Trying to reignite this thread. It seems appropriate, given that it is now in a Frankencar, and we’ve had to follow up on some hard-win lessons and trailblazing done by Doc.

If I screw up any of the technical issues, please defer to Skip’s version of events and knowledge if he chooses to post.

Quick Gist/BLUF: I ended up drooling over this thread when Doc was getting this build done. So I ended up calling Skip and putting some things together one winter on a smaller project, and it spiraled. Was just going to upgrade from a 2.8L KB on a short block that hadn’t been built yet. Mission creep took hold.

I now have this transmission, and thanks to the work that Skip and Doc put in, a similar project has taken shape- twin turbo car with a built engine. If you’re familiar with the Demon/TKM engine line, this would probably be considered “capable.”

Latest issues solved- getting a clutch for this that will handle the maximum power. If you’ve seen the IG page, that RPS quad carbon clutch is going on this. The ancillary issue was getting the right clutch slave fitted up- took a lot of shop time to get it fitted, and ended up with some machining being done on a Tilton to get one to fit to spec.

The picture above is some of Nate’s work in progress- having two sets of pipes for this on v-clamps. The one above is the drag/track pipe that is getting cutouts. The other one, because of emissions and inspection requirements, will be a cat pipe essentially being run at wastegate pressure for the street. I would never simply run the track setup outside of those conditions, and how dare anyone think or imply that 🤣

It’s been a long road, and it’s not done yet. But we are starting to get much closer to this thing hitting a dyno finally, and it couldn’t have happened without Doc stepping up on it as a trailblazer in the first place. A ridiculous amount of custom-now-production and one-off pieces came out of this, but hopefully the roadmap has been finally finished out for the project for future development/implementation for those looking to go this route.

I am pleased to share that we have specified this with a pair of PTE 7275 turbos, and a 3.40 pro out back. For those that implicitly understand what that will mean, the other uses for this will likely be on a road course- we are exploring another pumpkin for this to be swapped in that application and for general on-street use to prevent associated issues.

Why the timing now if the car isn’t quite done?
Well, a couple of reasons.

Skip and the guys have put up with me over the time period required to get this to this point, and it felt like they deserved a shout-out for one. Winter is coming, and that means build season for two. Finally, I’m preparing to exit the service, so this is attached by some manner to that time and timeframe, as date would have it. While that means it will likely sit for a lot of the winter… I will remain faithful to the experience of others over the course of it, as I hope this makes some serious passes at a number of events the next full season.

There are additional developments on the way, and I hope to be able to share those as well- I have a wrap ready to go on that may come out seriously hideous or not, but only time will tell and if I can help other people to avoid a potential mistake or get to see how something potentially cool turns out, great. Suffice to say, I have not seen it on the platform before, and I’m eager to see it after the execution.

In closing- games are afoot, and this did not occur in vain.

Soon.
What are the turbo specs and what are the camshaft specs?
Also, which Tilton throwout bearing did you use, and what modifications?
I like to buy a part that lasts for a LOOONG time, and so I like the clutch, so I need to know how the throwout bearing can be made to intelligently use every last gram of wear, and that quad disc clutch is the only clutch I've look at online that has the combination of features that seems to be so rare these days:
A) light weight, as the stock assembly hovers around 80 pounds, and the McLeod slap-on-disk adds 50-something pounds to a stock flywheel.
B) pressure plate that bolts directly to the flywheel, without stands, washers, spacers, or other such looseness-encouraging -over-time foolishness
If you are interested in any aero improvements, let me know.
C) a bonus I did not need, but it's nice: streetable manners.
 
Couldn’t tell ya on the TOB- I’m not a manual guy in the sense of having a ton of wrench time time on them. I believe we ended up trying to use one out of a stock setup, and ended up not have the appropriate clearances.IIRC from my discussions with Skip, it ended up with a Tilton 6000 series that still required some massaging to get it to fit.

I trust their work, but yes, one of my concerns is certainly longevity and stability. I know they’ve gone to great pains just getting this setup to fit together correctly, and it wasn’t a short process. As far as I’m tracking, we’re using a stock flywheel at full weight.

And to me, that’s probably our best choice overall- it may not be utterly from trying to find the very last 5% of the car’s ability, but we can continue to do so as this gets a season or two under it’s belt and mine. Besides that, I think we did a nice job of trying to find some drivetrain weight reduction in other places as well. The crankshaft is a Winberg, the clutch itself actually weighs less by a decent amount than the torque converter it replaced, the internals to the transmission are significantly lighter than the automatic and provide less drag, and the driveshaft was a special piece- 3.5” chrome moly.

All in all, it would seem that we’ve pulled about 70-80 pounds out of the reciprocating elements of the drivetrain over a stock automatic, and that’s before considering any drag added to drive the now-gone rotor pack of a supercharger… so I’m hoping this finds it’s legs well in terms of ability to climb RPM effectively both on and off boost.

The turbos are precision 7275 Gen 2 CEA. I have a “dyno hero number” in mind for this to run as proof-of-concept if nothing else, but they were picked for (gonna get heckled for this one) the power we wanted for straight line applications, not so much for a lower spool time in transient response on a road course- it’s their 428 stroker driving them, so I’m less concerned about getting out of a corner at full throttle and being down on torque. I think, as always, traction is likely to be our greatest concern and that any transient factors of gaining yet more power are going to be moot issues anyway 🤣

I would have to look up the cam specs, but essentially it was a custom grind with Thitek heads in mind- I think the LSA was a 113, and lift was a little better than stock. I would have to look for the specific lift and duration numbers, but think more healthy N/A road cam with a slightly wider LSA for the turbo application. In either case, it’s not particularly aggressive from a drag racing standpoint but should retain a little lope and road manners- I don’t figure we need anything that is designed to continue to make best power starting at 5500 RPM, as while the valvetrain can likely spin 7500 without issue… I don’t think we’ll be seeing it regularly. Right now 4th gear on the 1/4 should be hitting a trap speed around 165-170 based on bench numbers and our rear gear selection, and doing it around 7100-7200ish before we run out of road to the stripe. We’ll obviously need to tune around reality when we get there, and either a cam or gear change is likely- personally I think we can get away with just swapping a pumpkin to adjust, and that way there’s a choice and a spare depending on the event. It may be that for roll and 1/2 mile the 3.40 works well, and we may have to be somewhat more aggressive in RPM and gearing for 1/4 mile, or be prepared to add an addition shift before the traps- less than ideal, but there are design trade-offs in the project and we knew their would be.

Aero will be interesting at some point, particularly when I figure out what classes I can potentially run this in. I don’t have the seat time yet to outrun the setup that we’ve built, which I think is probably a good thing- I have some driving experience in other professional capacities, but not as a “race car driver.” To the extent that I have a clue, I’m still a complete new guy in road coursing, so that may be a while before this gets any other additions there. I figure the first year is going to be figuring out shock settings, tire combinations, and brake bias on this- I still haven’t ordered the road wheels I’m looking for or spec’ed the tires.

We have welds with a MT 275 Pro for the strip with matching fronts. 15” conversion is done, and we’ll be hopefully putting that to good use. I had a set of Rohana’s that had Nittos on them. I enjoyed that setup, but ended up selling them to a club friend when I realized that we had more time remaining in the project and they would be continuing to sit otherwise. This next time around will likely be litespeeds in magnesium trim for the next go-around. I think I will likely have the winter to figure that out.
And there’s the rub on that part- I’d like to be able to run One Lap next year, which means we have to play by their rules on tire selection for that event so that will come into play. I don’t expect to win anything, but I would like to get one under my belt and be able to play in a space where Challengers don’t typically go. It may not beat a pro driving a 911, but… I wouldn’t mind dusting off someone that is amateur hour, or in other words someone of matched skill 🤣

I think the biggest focus right now is just getting this finished out, seeing what it’ll run on the dyno, getting it out on the street, and getting the first few passes made before we start easing into other opportunities. Obviously auto-cross can be fun no matter the outcome, but I’m going to be trying to get this thing up to Club Motorsport or Loudon when I can so I can start getting seat time, and we can look at next steps. I don’t think this setup will even notice it was running as far as the drivetrain is concerned except for that pro gear, so that is again going to be an ongoing consideration. I’m much less worried about destroying a steel gear with street tires on this, but if we’re running the MTs on it with that much sidewall, it seemed to be the appropriate choice initially until we can start getting dialed in so we can make some passes.

It likely will not be this season at the tail end due to logistics and timing- while I don’t want to put it away for the winter, those particular objectives will probably have to wait.

That being said… I do still have the stock rims, and they do have snow tires on them 🤣
 
Dude I swear I started a hunt to see what happened with this transmission. I am at a real sticking point with my TT build and keeping it turned down to keep the manual transmission from blowing up, which I'm on my 3rd stock one.

I hate the idea of going TH400 or 4l80 because I'm not a track only guy, I like fast long drives with friends.

In my search for a happy median the sequential is ideal but the 20k price before install is not. All the best and if you need any assists with the Turbo setup I absolutely love mine and she is FAST FAST at roll race events.
 
Dude I swear I started a hunt to see what happened with this transmission. I am at a real sticking point with my TT build and keeping it turned down to keep the manual transmission from blowing up, which I'm on my 3rd stock one.

I hate the idea of going TH400 or 4l80 because I'm not a track only guy, I like fast long drives with friends.

In my search for a happy median the sequential is ideal but the 20k price before install is not. All the best and if you need any assists with the Turbo setup I absolutely love mine and she is FAST FAST at roll race events.
I’m not hopeful to be out this year at the pace to current completion- I’m fairly certain snow will be flying at home before I get to pick it up. It’s been a long process, but I’m definitely looking forward to the result, and sure I’ll see ya and/or some other folks out and about next season somewhere.

I think for me, the cost/benefit analysis was that it costs roughly the same as being on a 3rd transmission. It also means less frequent rebuilds, most of which I’m fairly confident I can probably effect either myself or with some local help from the boys- the overall lack of relative complexity in the design gives me some more confidence that being able to pull it, drain it, replace just about anything except the shafts themselves with available parts, and get it back in the car in a few hours with a couple extra sets of hands and a six pack rather than having to send it out to a competent party for a rebuild of a TH400 or 4L80E plays into it-I don’t have the skill yet to rebuild an automatic for use, much less high-performance use, in a home garage.
This thing is pretty stupid simple if you know how to check some tolerances and move flinstones-rock sized parts around.
So on the 5-15 year horizon for me, the total net benefit seems to make sense on the initial capital outlay. 🤷‍♂️

I also really like the idea of having the choice of more applications through gear spacing to do multi-event, and do it as a cruiser rather than being trailered. It’s not hurting my feelings that the tire/rear/6th ratio works out to about 2200 RPM at 70 MPH, and I get five nice choice before that for everything else 🤣

Overall, I would consider it to be the highest value solution, not the least expensive initially, for doing what I want and getting where I want with it. I will be looking forward in the future to setting up an automated pneumatic shifting assembly, and a mode switch to enable the factory paddle shifters at some point, as well as automated or semi-automatic shifting. That’ll probably be a 3-5 year project, and require me to do some serious reading, trial-and-error, and skill building to rig a controller up and make it play with everything else the right way. I’m sure it can be done, and most of what’s required already exists, but adapting it to the application is not something I expect to be a cheap weekend job. 🤷‍♂️🤣

However, I’m hoping that me getting some more time on road racing as a skillset builds with it, and that as we add capability to the car, the skillset is appropriate to the want/task.
In any event, I expect that it’ll beat up that transmission more than making 30-50 passes a summer at home, and wanted a rapid at-home rebuild capability rather than to have to keep cycling multiple transmissions for rebuilds and swaps to keep running.
 
Dude I swear I started a hunt to see what happened with this transmission. I am at a real sticking point with my TT build and keeping it turned down to keep the manual transmission from blowing up, which I'm on my 3rd stock one.

I hate the idea of going TH400 or 4l80 because I'm not a track only guy, I like fast long drives with friends.

In my search for a happy median the sequential is ideal but the 20k price before install is not. All the best and if you need any assists with the Turbo setup I absolutely love mine and she is FAST FAST at roll race events.
Invest in a higher-RPM valvetrain and extend the redline to 8000 RPM.

Then with similar torque, you will have a lot more power.
 
Invest in a higher-RPM valvetrain and extend the redline to 8000 RPM.

Then with similar torque, you will have a lot more power.
I mean, that’s definitely a method, and it would definitely make some pretty insane numbers doing it for sure 😁🤣

So I hear you, and I don’t disagree that it’s certainly a direction people can go. I will say for me that I’m trying to stay away from that route for a couple of reasons, even though the valvetrain components are stout pieces for this- nothing incredible, but definitely significant upgrades. While 7500 max is something Skip and I have discussed and we both seem more than comfortable that the car will do it, it’s worth noting a few things.

1) Valvetrain weight, stroke length, transmission gearing, rear end, driveshaft.

I’m going to be running inconel valves on the exhaust side for the thermal properties and longevity. So while the material should hold up for what we want, it’s introducing weight into the valvetrain. F=MA starts trying to catch up with us at that point, and because acceleration is a nonlinear equation… the faster we try and spin it to make power, the more we risk trying to make the springs control a heavier valve, the more spring we need, the stiffer the pushrod, etc. Doing all that on hydraulic lifters is a recipe for having a timing inconsistency from lifter squish, potentially just collapsing and destroying the lifters and cam in the process. I’m not running solids on it, and have no desire to do so.

It’s also a stroker block, so now we’re dealing with “proof of gravity”on that side as well. Gravity and I have had a strange and very personal relationship in a prior professional setting, so the g-load of acceleration might get worked out on the valvetrain side, but even then we’re talking about wear and tear on the rotating assembly at an increased stroke length to stick.

We have six gears to work with on a radial tire, so running out of gear and needing to spin it to the moon on a three speed with a wider gear spacing is not an issue. However, heat is. The transmission was notably not a budget item, and I would prefer to not have to continuously order new gear sets to try and turn a few hundred RPM more because of the increased wear factor.

As far as the rear gear, same issue applies- yes, we’re running a pro gear out back, but simply smashing more heat at it with a nonlinear increase at that rotational speed just for a little more HP at the big end creates a longevity issue.

Finally, all that would be great, but we’re also getting into living with critical speed for harmonics in the driveshaft at that point- hot components on either end get to contend with the vibration on top of doing it while stressed.

2) Big turbos

We’re running a pair of 7275s on this. As it is, now we’d also be talking about impeller speeds there. At some point, there’s a crossover of how much we really need to push the turbos to make the power we want. The turbos themselves should support over 2000 flywheel comfortably, so the point becomes moot- we can simply turn the boost up at lower RPM rather than trying to spin everything else faster.

3) Traction

This is a stock-style IRS setup on a radial. While we have some great coil overs on it, and replaced most of components with BMR and AAR stuff, at some point we have the ability to make more power at a faster rate than the tire will probably handle anyway for the 1/8th and 1/4 mile on that setup given the weight of the car- it’s a full interior with a backseat delete.

So I hear ya, and it’s 100% a valid direction for someone trying to gain the maximum amount of final efficiency from this as a race engine… but we’re already going to be capable of making more power than we can likely use at this point already, and spinning it to 8K is a greater risk of chewing components up much more quickly to make the same power levels we can hit simply punching a few setting in on a boost controller 🤷‍♂️

I would actually be just fine if we hit some of our goal numbers and found ourselves traction limited and running lower RPM than higher over the course of events- it’s not a drag-only car, and will be running in Street/Heavyweight classes rather than KOS and Outlaw. No desire to try and compete there, and have to tear the car apart to be competitive. We still have factory seats in this thing. 🤣
 
If you have ample power and your limitation is traction, then you are in a territory where more weight on the rear wheels may gain a net positive effect. Are you allowed the use of unilimited aerodynamic aids? If so a couple wings with a high lift-to-drag ratio can net you more stick in the rear. Another route, if you are severely traction-limited, is to place ballast at the very back of the car, to take advantage of leverage to gain more weight on the rear wheels than you are actually adding. Unlike wings, this is a static load that does not require speed to increase. On my spreadsheet, adding 300 pounds to the car 3 feet behind the rear axle centerline takes 90 pounds off of the front wheels and places 390 on the rear ones.
 
Trying to reignite this thread. It seems appropriate, given that it is now in a Frankencar, and we’ve had to follow up on some hard-win lessons and trailblazing done by Doc.

If I screw up any of the technical issues, please defer to Skip’s version of events and knowledge if he chooses to post.

Quick Gist/BLUF: I ended up drooling over this thread when Doc was getting this build done. So I ended up calling Skip and putting some things together one winter on a smaller project, and it spiraled. Was just going to upgrade from a 2.8L KB on a short block that hadn’t been built yet. Mission creep took hold.

I now have this transmission, and thanks to the work that Skip and Doc put in, a similar project has taken shape- twin turbo car with a built engine. If you’re familiar with the Demon/TKM engine line, this would probably be considered “capable.”

Latest issues solved- getting a clutch for this that will handle the maximum power. If you’ve seen the IG page, that RPS quad carbon clutch is going on this. The ancillary issue was getting the right clutch slave fitted up- took a lot of shop time to get it fitted, and ended up with some machining being done on a Tilton to get one to fit to spec.

The picture above is some of Nate’s work in progress- having two sets of pipes for this on v-clamps. The one above is the drag/track pipe that is getting cutouts. The other one, because of emissions and inspection requirements, will be a cat pipe essentially being run at wastegate pressure for the street. I would never simply run the track setup outside of those conditions, and how dare anyone think or imply that 🤣

It’s been a long road, and it’s not done yet. But we are starting to get much closer to this thing hitting a dyno finally, and it couldn’t have happened without Doc stepping up on it as a trailblazer in the first place. A ridiculous amount of custom-now-production and one-off pieces came out of this, but hopefully the roadmap has been finally finished out for the project for future development/implementation for those looking to go this route.

I am pleased to share that we have specified this with a pair of PTE 7275 turbos, and a 3.40 pro out back. For those that implicitly understand what that will mean, the other uses for this will likely be on a road course- we are exploring another pumpkin for this to be swapped in that application and for general on-street use to prevent associated issues.

Why the timing now if the car isn’t quite done?
Well, a couple of reasons.

Skip and the guys have put up with me over the time period required to get this to this point, and it felt like they deserved a shout-out for one. Winter is coming, and that means build season for two. Finally, I’m preparing to exit the service, so this is attached by some manner to that time and timeframe, as date would have it. While that means it will likely sit for a lot of the winter… I will remain faithful to the experience of others over the course of it, as I hope this makes some serious passes at a number of events the next full season.

There are additional developments on the way, and I hope to be able to share those as well- I have a wrap ready to go on that may come out seriously hideous or not, but only time will tell and if I can help other people to avoid a potential mistake or get to see how something potentially cool turns out, great. Suffice to say, I have not seen it on the platform before, and I’m eager to see it after the execution.

In closing- games are afoot, and this did not occur in vain.

Soon.
what’s the latest on this
 
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