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Discussion Starter #401 (Edited)
I actually cant see the point in these Hank. The RDU is already isolated from the suspension because its basically bolted to the chassis so who cares how much it moves around(to a point of course) All I can see you getting is more NVH. Cant see how its going to affect handling at all.
[Edit in red]

My reasoning is now that I'm throwing more torque to the rear than Ford had intended, it will start to overstress the existing components. To prevent any excess movement of the RDU, I opted for the Powerflex Black Series RDU bushing inserts. The typical driveshaft u-joint angle limit is 3 degrees maximum up to a certain driveshaft rpm (say 5,000). The RS has a CV joint at the RDU. I don't know the CV joint angle limit maximum, but minimizing the RDU deflection will maintain a long, healthy life for the CV joint. The RS Workshop Manual lists the max articulation of the flex couplings at 7 degrees. I didn't measure the driveshaft angles at max deflection of the factory bushings, but I was able to deflect the front of the RDU by hand almost 1/2". I'm sure I could have got a higher deflection with a pry bar. After installing the RDU bushing inserts I wasn't able to move the RDU at all by hand. This greatly reduces the potential for a driveshaft failure by the added torque being sent to the RDU. And although I've never had rear wheel hop with my RS (yet), the bushing inserts should help prevent that. And we all know that OE rubber bushings don't last that long with what I've been doing to them for years. Eventually they will wear out. The bushing inserts might add some life to them. It's a test for me because I've never ran bushing inserts before.

RDU Programming tidbit:
If I don't like the extra torque for the twisty bits of autox, then I will have Kacper dial down the extra torque for just my launches only. If my tires can hold the 25% torque increase for launch only, then I will continue testing to figure out what torque I add for the twisty bits.
 
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[Edit in red]

My reasoning is now that I'm throwing more torque to the rear than Ford had intended, it will start to overstress the existing components. To prevent any excess movement of the RDU, I opted for the Powerflex Black Series RDU bushing inserts. The typical driveshaft u-joint angle limit is 3 degrees maximum up to a certain driveshaft rpm (say 5,000). The RS has a CV joint at the RDU. I don't know the CV joint angle limit maximum, but minimizing the RDU deflection will maintain a long, healthy life for the CV joint. The RS Workshop Manual lists the max articulation of the flex couplings at 7 degrees. I didn't measure the driveshaft angles at max deflection of the factory bushings, but I was able to deflect the front of the RDU by hand almost 1/2". I'm sure I could have got a higher deflection with a pry bar. After installing the RDU bushing inserts I wasn't able to move the RDU at all by hand. This greatly reduces the potential for a driveshaft failure by the added torque being sent to the RDU. And although I've never had rear wheel hop with my RS (yet), the bushing inserts should help prevent that. And we all know that OE rubber bushings don't last that long with what I've been doing to them for years. Eventually they will wear out. The bushing inserts might add some life to them. It's a test for me because I've never ran bushing inserts before.

RDU Programming tidbit:
If I don't like the extra torque for the twisty bits of autox, then I will have Kacper dial down the extra torque for just my launches only. If my tires can hold the 25% torque increase for launch only, then I will continue testing to figure out what torque I add for the twisty bits.
I understand Hank the logic you have used here but I also have a great deal of respect for the people that do the R&D on these things as I'm related to a couple of them. Don't get me wrong all info is good info and If I was racing one i'd be interested to see if there was a performance difference but I'm sceptical for this application. Suspension bushes for a track car I can understand because it's max rigidity and not much else matters. I personally have little respect for the people that make these sort of components and as we have seen many many times with failed aftermarket engine mounts the R&D is lacking or non existent.
At the end of the day the standard bushes can only deflect so far before they bottom out so to speak no matter how much torque you put through them and if I was designing a flexible mounting system I'd ensure the limit of deflection was less than the maximum allowable drive shaft joint angle.
Interestingly with regards to coupling deflection angles I see the front shaft figures and wonder how far beyond people go when removing front struts without pulling the drive shafts.
The reprogramming I'll follow with interest but wont be doing myself. I'd be interested to know how close to the max torque limit the standard RDU module is programmed. I can see the logic of the OEM programme in only applying rear power after the front in a launch and wonder how removing this will affect the driveline longevity.

Ciao
 

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I wonder how aggressive the launches will become with all these changes in the system.


For example, brutal launches common on Audi RS3 and Audi TT RS vehicles.
While the manufacturer has put some safety measures, tuners will often bypass these.
I have seen quite a few breaking badly because they had the launch of their life so to say.
 

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@Tongue Twinster i wouldn’t be worried for 99% of us on this forum. Normal street tires (not drag radials) will never let you hook up strong enough to snap axles. Also I’ve never, and probably never will launch on a prepped drag surface. As hanks video proves it will break traction long before record breaking 60’ times

drag radials and a prepped surface is a whole ‘ other story though.
 

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Discussion Starter #405
Pictures & Video along the way:
RDU Programming. More information here.

Notes:
  • I recommend upgrading the (3) RDU bushings with Powerflex inserts before re-programming your RDU due to the increased rear torque.
  • Many thanks to @Kacper to complete this programming for us to use.








 

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Discussion Starter #407
Pictures & Video along the way:
ABS Programming. More information here.

Notes:
  • This modification is not 100% tested. For now, it works as intended. I will continue to test in upcoming Autoxes.
  • A bonus of this ABS Programming is an alternative to Ford's Drift Stick. See the end of the video (last 30 seconds) for details.
  • Many thanks to @Kacper to complete this programming for us to use.










 
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@Hank I may end up getting the street rdu bushing inserts for peace of mind if it moves around as much as you say. I'm sure there will still be some nvh increase with those, hopefully not too terrible.

I know you have one so what are your thoughts on the ptu brace. I know the aftermarket piece is definitely more stout looking and picks up another bolt, but is the factory brace really insufficient?
 

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Discussion Starter #409
@Hank I may end up getting the street rdu bushing inserts for peace of mind if it moves around as much as you say. I'm sure there will still be some nvh increase with those, hopefully not too terrible.

I know you have one so what are your thoughts on the ptu brace. I know the aftermarket piece is definitely more stout looking and picks up another bolt, but is the factory brace really insufficient?
My autox buddy drives his built block/head/aftermarket turbo mad power RS daily. He runs the yellow Powerflex RDU bushing inserts. No noticable NVH.

I highly recommend the Mountune PTU brace. The factory brace only has (3) mounting holes, whereas the Mountune has (4). Picking up that extra mounting location provides extra stiffening in that area.
 

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My autox buddy drives his built block/head/aftermarket turbo mad power RS daily. He runs the yellow Powerflex RDU bushing inserts. No noticable NVH.

I highly recommend the Mountune PTU brace. The factory brace only has (3) mounting holes, whereas the Mountune has (4). Picking up that extra mounting location provides extra stiffening in that area.

Looking at the yellow. Mountune has it but not applicable on the coupon code they have.

Any suggestion on where to pick one up @Hank?
 

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I went ahead and got my yellow bushings from mountune while I ordered the brace. Should be able to get them installed tomorrow, I'll give my impressions after I get them in.
 

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Discussion Starter #412
Looking at the yellow. Mountune has it but not applicable on the coupon code they have.

Any suggestion on where to pick one up @Hank?
I got my black series inserts from Powerflex USA. They should have the yellow in stock as well.
 
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Discussion Starter #413
Pictures along the way:
Autox 09/06/20 Results. More information here.

Notes:
  • Fastest Time of the Day out of 48 drivers by 0.598 seconds. 1st in SM by 5.108 seconds.
  • Potenza RE-71R tires at 34F/21R tire pressures hot. -3.1F/-2.9R camber. Zero toe F/R.
  • RDU module programmed for +12.4% torque increase, ABS module programmed with Soft Drift to eliminate Ford's Brake Assist.
  • I ran this Autox on a Tune+ 93 octane map that was revised twice afterwards. LC rpm was set to 5000 rpm. Soon I will be on E30 fuel.
  • Rear sway bar = firm. Front sway bar = middle.
  • Front shocks = 3 from firm. Rear shocks = 9 from firm (half way).
  • Vehicle race weight = 3180 lb (just below 1/4 tank of fuel, no driver).
  • RE-71R tires are now at 47 runs.
  • Total of 221 launches on the stock clutch.
  • Odometer 5925 miles today. Trailered my RS to the event.
 

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Been watching all your stuff. I’d say with confidence that was the tightest and cleanest run I’ve seen, with the hardest launch for sure. Beautiful
 

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Discussion Starter #415
So in the Cracking the Code: RDU Tuning Development thread I mentioned in my after race report that I had great results at the 09/06/20 Autox, but there were other (humorous) issues abound. Here's the story...

Before the Autox I sent a Tune Update Request to Tune+ in order to make me an E30 map. Adam sent me a 93 octane map to log and check things out first. I sent him logs and he sent me a revision. Adam don't work on weekends, so I ended up racing at the Autox on vB of the tune. In a picture I had with old instructions there used to be (5) map slots with different LC rpm settings. On my first run at the 09/06/20 Autox, I launched at 5000 rpm. Car was a beast, but I spun just a tad on the launch. I checked the map slot and the tach indicated "1". LC was 5000 rpm. On map slot 2 the LC was 4500 rpm. Map slots 3, 4, and 5 didn't have a LC (seemed free rev to anything).

For Autox run #2 the map slot was changed to #2. I launched at 4500 rpm, then my RS fell on it's face. My mind couldn't comprehend why the performance had dropped dramatically. Was the clutch slipping? For the first few corners I couldn't go above 4000 rpm. Foot to the floor pretty much the entire run. I crossed the line with a 41.545. That would have been good enough for 10th place out of 48. An email response from Adam the day after the race taught me a lesson. He no longer sets LC rpm. Adam wants us to use the Cobb AP to set the LC rpm. What I had done on run #2 was change from slot 1 (full power) to slot 2 (economy/limited power/bad fuel safety net). What did I do after run #2? I changed back to slot 1 and kill mode was re-engaged.
 

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Discussion Starter #416
Ordered a Tune+ Ethanol Content Analyzer and test kit. E30 fueled RS coming to an Autox near you. Street Mod class allows diesel, gasoline or any gasoline/ethanol blend. Can't wait to see the extra timing in the datalogs and feel the extra power up top. The next (2) autoxes in my area of Louisiana were cancelled due to emergency vehicles damaging the parking lot while staging for hurricane relief (heavy trucks for electrical companies and supplies, temporary command tent stakes, etc.).
 
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