tadeuzagallo skrev:

therealpinto skrev: I am quite heavily invested in the Sierra diff platform Oh interesting! Is the Sierra the same as an Explorer? 8.8, independent rear suspension, 31 spline? It so, that'd have made my life a lot easier 😅 but I wasn't aware of it...

I think you two are thinking about different Sierra's.

Gustaf is thniking of this Ford Sierra made in the 80's.

https://sevener.fr/articles_redac/Sierra_diff.pdf
I have one in my Westfield with ~270hp.

Yeah, sorry, Euro Ford Sierra. Merkur XR4Ti for the US boys and girls :-)

Dione made my axles at a reasonable price. For prop shafts, a lot of people seem to use Svea Kardan in Stockholm.

tadeuzagallo skrev:

therealpinto skrev: Interesting info on the differentials. I am quite heavily invested in the Sierra diff platform but always nice to get more info on options. Regarding drive shafts; I have had Dione Kullager i Uppsala make me custom shafts, good to deal with and not very expensive. But I am sure there are more people doing it now for the drifting scene too. Oh interesting! Is the Sierra the same as an Explorer? 8.8, independent rear suspension, 31 spline? It so, that'd have made my life a lot easier 😅 but I wasn't aware of it... I'm talking to a friend in the US who has a machine shop and makes Miata parts. He made himself axles using the 930 108mm CV, and I'm trying to talk him into developing axles for Super 8.8 as well. Right now I'm 3D scanning the subframe and both differentials, I'm going to tack the diff into place so I can get measurements, and I'll get quotes for the axles. I knew it was going to be expensive to get custom axles that can handle 1000hp, but damn, it's much worse than I expected. Do you know if Dione Kullager also makes driveshafts? Either way I'll have a chat with them, maybe I can get some better pricing.

If you mean propshaft, I can help you with that 😊👍

therealpinto skrev:

Yeah, sorry, Euro Ford Sierra. Merkur XR4Ti for the US boys and girls :-) Dione made my axles at a reasonable price. For prop shafts, a lot of people seem to use Svea Kardan in Stockholm.

Oh, I see. I read Sierra and for some reason thought of the truck, but that's GMC so it doesn't make any sense 🙃

erikjakan skrev:

If you mean propshaft, I can help you with that 😊👍

Yes, exactly! I should get used to saying propshaft instead of driveshaft 😅. I'm gonna send you a message, thanks!

tadeuzagallo skrev:

Oh, I see what you meant now, splitter diffusers, not the actual diffuser. The front end is still just a draft, but I'm trying a slightly different idea. I still haven't ran any simulations, but the whole splitter is airfoil shaped, which then feeds the wing, similar to a dual element wing. The splitter profile needs a lot of work, and the second element is just a profile I was using as a single element rear wing, so it might not be the best profile, but that's the general idea.

Looks like you are well on the way, the tunnels looks very agressive though in their expansion/curvature, buts its not super easy to see

How do you plan to make the aero? Its an elaborate shape to make, though with a lot of potential.

If you are interested in simulations, have you tried optimum lap to get a rough estimation on how the car will do on different swedish tracks?

Cédric skrev:

Looks like you are well on the way, the tunnels looks very agressive though in their expansion/curvature, buts its not super easy to see

I think the overall heigh of the ramp is pretty mild, but I didn't do any work on the curve itself. It was just a quick draft to see if it would work. I'm busy with finishing the top and the fenders, then I have to make the body watertight and I'll come back to refine the splitter and run some more simulations.

Cédric skrev:

How do you plan to make the aero?

From the splitter, I'm think about plywood for center section and for the profiles 3D printed cores wrapped in carbon fiber, with aluminum tubes running through them, and aluminum mounts. I haven't tried this method yet, but I've seen other people having success with it, so I'm hoping for the best.

Cédric skrev:

If you are interested in simulations, have you tried optimum lap to get a rough estimation on how the car will do on different swedish tracks?

I have not tried it yet... I started reading more about it the other day, then realized it was Windows only and haven't used my windows computer since. I'll give it a try though, it's a great reminder to come back to it, thanks!

tadeuzagallo skrev:

Cédric skrev: Looks like you are well on the way, the tunnels looks very agressive though in their expansion/curvature, buts its not super easy to see I think the overall heigh of the ramp is pretty mild, but I didn't do any work on the curve itself. It was just a quick draft to see if it would work. I'm busy with finishing the top and the fenders, then I have to make the body watertight and I'll come back to refine the splitter and run some more simulations. Cédric skrev: How do you plan to make the aero? From the splitter, I'm think about plywood for center section and for the profiles 3D printed cores wrapped in carbon fiber, with aluminum tubes running through them, and aluminum mounts. I haven't tried this method yet, but I've seen other people having success with it, so I'm hoping for the best. Cédric skrev: If you are interested in simulations, have you tried optimum lap to get a rough estimation on how the car will do on different swedish tracks? I have not tried it yet... I started reading more about it the other day, then realized it was Windows only and haven't used my windows computer since. I'll give it a try though, it's a great reminder to come back to it, thanks!

Fibre wrapped prints should work great, ive seen it used before with good results. Should yield some quick results from design to product.

Optimum lap is pretty nice, since you can alter alot of parameters, or sweep different paramters to see what how different changes affect the lap time, or how different gearings/wheel sizes, power curves will work etc etc. Best of all is that its free

Just dropping my random thoughts as I plug along: I was talking to a friend who drives a 450hp Miata and he told me about some concerns about the K24 + 8HP70 combo... apparently the transmission doesn't like high RPMs either in the input or output shaft. I read on the internet 8000rpm on the input is ok, which is what I'd be running. My friend says 7200rpm is safest, but 8k "should"a be fine. Now for the output he says nothing above 6000rpm, which would mean 6000 engine rpm in 6th gear (1-to-1 gear). With my current final drive that would be 182km/h, so that sucks.

I'm not quite sure where I'll go from here, I'm still waiting for the parts from KPower to mount the engine, so I still have a little time. The "right" answer would obviously be a sequential transmission, but I don't think I can afford that right now. I reached out to Sellholm to get a quote, but my hopes are quite low. The more likely scenario is that I'll get a taller gear for the 8.8 diff and just send it with the 8HP for now. Or maybe a "cheap" used sequential transmission will my manifest in my garage 🙃

In the mean time, I got a friend in the US to make me some axles. I shipped out my 34-spline stubs to him yesterday, he'll make some flanges to mate to 930 CV joints and an axle shaft. That should be able to handle all the power I need, and then some.

Have you considered running the BMW 7 speed DCT gearbox?
But i don't know if that will work better @ 8000R/pm

TexasRx7 skrev:

Have you considered running the BMW 7 speed DCT gearbox? But i don't know if that will work better @ 8000R/pm

I considered it before I chose the 8HP, I don't think the RPM is a problem with them, but I've seen a lot more people blowing them up due to tuning issues. The 8HP was also a lot cheaper, and should be able to handle as much torque as I'd make even with 1000hp, all with the stock torque converter, so it seemed like a really good fit, I just wasn't aware of the RPM issue.

I got a quote from Sellholm, and I'll consider it, but I don't think it's feasible for next season at this point. Looks like the perfect setup, but just the box would cost me almost 5x the 8HP + adapter, which I already have.

The other benefit of the 8HP is that I can get rid of the clutch pedal, which would make it a lot easier to fit the air jack. I don't know, considering how popular these swaps are becoming, I might roll the dice and hope for the best.

tadeuzagallo skrev:

I considered it before I chose the 8HP, I don't think the RPM is a problem with them, but I've seen a lot more people blowing them up due to tuning issues. The 8HP was also a lot cheaper, and should be able to handle as much torque as I'd make even with 1000hp, all with the stock torque converter, so it seemed like a really good fit, I just wasn't aware of the RPM issue. I got a quote from Sellholm, and I'll consider it, but I don't think it's feasible for next season at this point. Looks like the perfect setup, but just the box would cost me almost 5x the 8HP + adapter, which I already have. The other benefit of the 8HP is that I can get rid of the clutch pedal, which would make it a lot easier to fit the air jack. I don't know, considering how popular these swaps are becoming, I might roll the dice and hope for the best.

Have you checked out this guy? He runs a K-swap with what I think is the same gearbox?
https://www.youtube.com/@FEMEDIA

Oh, I had seen his car, but didn't realize he runs an 8hp70 as well. I'll try sending him a message.

Jk95 skrev:

Have you checked out this guy? He runs a K-swap with what I think is the same gearbox? https://www.youtube.com/@FEMEDIA

I had a chat with him on Instagram, he was very helpful. Seems to be working fine for him up to 8300rpm with a 3.54 final drive. My redline should be 8000 and 3.55 final drive, so very similar. While the fact that one person hasn't had a problem with it isn't exactly scientific, it gives me a little bit of peace of mind, and makes me think it's worth giving it a shot.

As I said, my thoughts are that the 8hp is becoming super popular, so if it does become a problem I'd hope someone will come up with a solution, I was reading about some people already upgrading the internal oil pump gears. On top of that, I'd have to destroy 12 transmissions before the sequential paid for itself, so I'll give it a shot.

tadeuzagallo skrev:

Jk95 skrev: Have you checked out this guy? He runs a K-swap with what I think is the same gearbox? https://www.youtube.com/@FEMEDIA I had a chat with him on Instagram, he was very helpful. Seems to be working fine for him up to 8300rpm with a 3.54 final drive. My redline should be 8000 and 3.55 final drive, so very similar. While the fact that one person hasn't had a problem with it isn't exactly scientific, it gives me a little bit of peace of mind, and makes me think it's worth giving it a shot. As I said, my thoughts are that the 8hp is becoming super popular, so if it does become a problem I'd hope someone will come up with a solution, I was reading about some people already upgrading the internal oil pump gears. On top of that, I'd have to destroy 12 transmissions before the sequential paid for itself, so I'll give it a shot.

How fun, excited to see how your build turns out

tadeuzagallo skrev:

I had a chat with him on Instagram, he was very helpful. Seems to be working fine for him up to 8300rpm with a 3.54 final drive. My redline should be 8000 and 3.55 final drive, so very similar. While the fact that one person hasn't had a problem with it isn't exactly scientific, it gives me a little bit of peace of mind, and makes me think it's worth giving it a shot. As I said, my thoughts are that the 8hp is becoming super popular, so if it does become a problem I'd hope someone will come up with a solution, I was reading about some people already upgrading the internal oil pump gears. On top of that, I'd have to destroy 12 transmissions before the sequential paid for itself, so I'll give it a shot.

I believe there's already upgraded aftermarket internals for the 8HP gearboxes that makes them handle more power and RPM. They are growing more popular in all kinds of motorsport from dragracing to drifting.

Westersund skrev:

I believe there's already upgraded aftermarket internals for the 8HP gearboxes that makes them handle more power and RPM. They are growing more popular in all kinds of motorsport from dragracing to drifting.

Interesting! I've been doing some googling, but haven't found much yet, seems like I have a lot more research to do, but that's great to hear, thank you!

On an unrelated note, the fastback is mostly together! There are still a couple panels that are just in place, but it's 99% there, then I just have to go over every joint again and make sure it's fully glued 😅

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It's a massive pain to glue all this, and since it was my first time doing it I'm learning as I go, which makes me wish I could do it again from scratch lol, but no way I'm printing all this stuff again.

I posted a couple time lapses of the process on Instagram, lots of blue tape, then gluing, occasionally breaking it apart and re-gluing: https://www.instagram.com/p/C0jVPe7tck9/

Are these panels 3D-printed? PLA?

stilldouble skrev:

Are these panels 3D-printed? PLA?

Yeah, exactly! I split the top into 46 panels. They are 250x250mm and 4mm thick (10% infill). Because of the curvature about 4 or 6 of them had to split in half once more.

Well done, that roof is mad in a very good creative way I dont remember if you wrote it somewhere here, will you put a sheet of cf/gf fibre on it ?

tadeuzagallo skrev:

I posted a couple time lapses of the process on Instagram, lots of blue tape, then gluing, occasionally breaking it apart and re-gluing: https://www.instagram.com/p/C0jVPe7tck9/

I read the previous post on this with great interest and was envious of your skills to create it.
But I didn't realize how far you've come in the build. Great work and thanks for a super interesting thread!

Marcus Gustafsson skrev:

I read the previous post on this with great interest and was envious of your skills to create it. But I didn't realize how far you've come in the build. Great work and thanks for a super interesting thread!

Thanks! It's my first time doing any of this: 3d modeling, 3d printing car parts, CFD, composites... it's a bit scary, and learning is always a bit messy, but I'm happy with how things are coming along. I hope I manage to get a finished part 🤞

Cédric skrev:

Well done, that roof is mad in a very good creative way I dont remember if you wrote it somewhere here, will you put a sheet of cf/gf fibre on it ?

Thanks, that's kinda what I'm aiming for haha.

I don't think I wrote it anywhere yet, but my plan is to smoothen out the print, lay carbon fiber on it, ditch the 3d printed part and add some foam reinforcements underneath. I might mix the carbon fiber with either fiberglass or dioleen, to keep the costs down, after all it's the first time I'm trying this, I'm still skeptical it might all go terribly wrong.

I'm borrowing the idea from one of RuskiWeldFab's video, seems to be a cheap and quick way to get it done, and I think the results look pretty good for what I need: https://youtu.be/D9iv8a8d8Os?si=Ra33bKRxSht0HVzw