Whats new in the RT4?

Mark Brye · #1 (**permalink**) 11-27-2019, 07:30 AM

I see that Backdraft now has an RT4 out. Anyone know what the changes are from the RT3? About what chassis number did the RT4 changeover start?

ront49 · #2 (**permalink**) 11-28-2019, 05:34 AM

Haven't heard of the RT4 but to get the correct and immediate answer, call Reg Dodd at Backdraft Racing.... I'll check their web page and see if one is listed.

samyt · #3 (**permalink**) 12-02-2019, 09:33 AM

Fro my understanding, the new RT4 chassis will consist of the following:
Ford 8.8 diff 3.55 ratio locker
The rear suspension layout/geometry is BMW E92 M3
The rear uprights are BMW E92 M3
The rear of the chassis will now have a true coil over
The floor of the chassis will now be steel
The cockpit will have more space as there will be no need for a trailing arm mount
The chassis will have a dropped floor
The chassis will come with a wide seat standard

Just be careful as they are slowly release some of these features in the RT4, not all these features are available on the current RT4's...the 2020 RT4 will probably have all of them, I will check with whomever you order yours before hands...I highly recommend you talk to Jay from VMS as he is the Maestro and the only expert in Backdrafts.

Best of luck

TheNewGuy · #4 (**permalink**) 12-02-2019, 12:12 PM

Jay is building mine and has definitely been extremely patient and helpful with all of my questions. He said most likely mine will not go into production for a couple months so hopefully I will benefit from that and get these new options.

Cashburn · #5 (**permalink**) 12-02-2019, 05:44 PM

Price increase looming in 2020. Any deposits in by 12/24 will get all the RT4 upgrades at current pricing. RT4 model upgrades include:

All new components (NO REMANUFACTURED PARTS)
New Rear suspension design
Upgraded differential , Ford Traction-Lok diff with a 3.55 ratio.
Rear Coil over shocks
Steel floors
Dropped Footbox
Revised seat design
Revised Front struts
Revised rear axle design

Cashburn · #6 (**permalink**) 12-02-2019, 05:46 PM

Quote:

Originally Posted by TheNewGuy

Jay is building mine and has definitely been extremely patient and helpful with all of my questions. He said most likely mine will not go into production for a couple months so hopefully I will benefit from that and get these new options.

You’ll be in production in about a week. Arrival will be March - April.

LudicrousSpeed · #7 (**permalink**) 12-23-2019, 05:27 AM

Quote:

Originally Posted by Cashburn

Price increase looming in 2020. Any deposits in by 12/24 will get all the RT4 upgrades at current pricing. RT4 model upgrades include:

All new components (NO REMANUFACTURED PARTS)
New Rear suspension design
Upgraded differential , Ford Traction-Lok diff with a 3.55 ratio.
Rear Coil over shocks
Steel floors
Dropped Footbox
Revised seat design
Revised Front struts
Revised rear axle design

Is the Ford Traction-Lok a limited slip?

Cashburn · #8 (**permalink**) 12-23-2019, 12:36 PM

Quote:

Originally Posted by LudicrousSpeed

Is the Ford Traction-Lok a limited slip?

Yes it is.

Mark Brye · #9 (**permalink**) 12-24-2019, 09:57 AM

This is really big news. I am surprised that there is not more talk about these upgrades. The differential and rear drivetrain always seemed to be a talking point and concern for people shopping for a cobra. I would think this RT4 puts that concern to rest.

Jay, will you have any pictures in your gallery of the new rear suspension, differential and rear suspension assembly on your site? Just wondering what this all looks like.

Thanks,

Mark

Cashburn · #10 (**permalink**) 12-24-2019, 10:57 AM

I believe Backdraft is working on updating their site to reflect the changes. We are waiting on the latest RT4s in production.

jeffgrice · #11 (**permalink**) 12-28-2019, 04:54 AM

Hi Mark

The comments herein about what is included is comprehensive. And it is true that they have been running changes during RT4 production.

A key reason to watch buying existing stock. There are MANY RT3s in inventory and some RT4s.

Most of our customers order to spec so as a result we only stock a few current models.

Happy to help you out!

Jeff

586.489.5990
jeff@nostalgicmotoring.com
nostalgicmotoringltd.com

jeffgrice · #12 (**permalink**) 12-29-2019, 04:16 AM

Mark, here's a more exhaustive list of improvements over the RT3

Improved and stiffened chassis. Completely redesigned

Safer chassis (side impact protection) with better reinforcement to the outer body.

Metal floors instead of fiberglass

Fully adjustable BMW suspension

Improved sawyer geometry

Far better ride

Far better handling

Additional passenger compartment room

Additional driver compartment room

Wider seats

Drop drivers side floor for additionally leg room and through the windshield visibility

Limited slip Ford Motorsports differential now standard

Best regards

Jeff - Nostalgic Motoring

Tom Wells · #13 (**permalink**) 12-29-2019, 05:33 AM

Quote:

Improved sawyer geometry

Is that from the Pacific Northwest?

spdbrake · #14 (**permalink**) 12-29-2019, 07:48 AM

"Improved sawyer geometry"

The only reference I can come up with on Sawyer Geometry is a vague reference to Sawyer measurements on Bicycle frames. I guess it could apply although it seems a stretch analogy.

Maybe its a coined term like "Frikalishious".

Tom Wells · #15 (**permalink**) 12-30-2019, 06:49 AM

On second thought, maybe it has to do with muffler bearings or blinker fluid?

jeffgrice · #16 (**permalink**) 01-01-2020, 04:19 AM

Mark and others,

In addition to the valuable feedback herein on VAST improvements of the RT4 over the RT3 I took pictures of the frame/suspension so you also had visual references.

RT3: https://spaces.hightail.com/receive/ewvX91hrX7

RT4: https://spaces.hightail.com/receive/Ioh185cVDw

Happy to help!

Jeff

spdbrake · #17 (**permalink**) 01-01-2020, 05:19 AM

Thanks Jeff!

I don't really see any changes in the front suspension other than the new sway bar, although they're probably in there somewhere.

The center section looks cleaner and the multi mounting for the trans and sliders for the sidepipes are great. I see the dropped drivers foot box.

On the rear though the suspension looks amazing. I really love how the rear end geometry looks to stay aligned as it moves through its travel. Also the camber and Toe links adjustments.

Man that is one short driveshaft.

Are the rear brakes GM? Looks like it from the parking brake.

jeffgrice · #18 (**permalink**) 01-02-2020, 04:18 AM

Quote:

Originally Posted by spdbrake

Thanks Jeff!

I don't really see any changes in the front suspension other than the new sway bar, although they're probably in there somewhere.

The center section looks cleaner and the multi mounting for the trans and sliders for the sidepipes are great. I see the dropped drivers foot box.

On the rear though the suspension looks amazing. I really love how the rear end geometry looks to stay aligned as it moves through its travel. Also the camber and Toe links adjustments.

Man that is one short driveshaft.

Are the rear brakes GM? Looks like it from the parking brake.

You are very welcome!

The stock front brakes are BMW and rear VW.

Take care

Jeff

Cashburn · #19 (**permalink**) 01-04-2020, 10:59 AM

Those photos are an RT3.5 ... true 4s have new coil over design in front.

jeffgrice · #20 (**permalink**) 01-05-2020, 08:29 AM

Quote:

Originally Posted by Cashburn

Those photos are an RT3.5 ... true 4s have new coil over design in front.

According to Reg the car shown (in the RT4 folder) is an RT4 (not an RT3.5). The front suspension change you maybe referring to is a different strut manufacturer for the front of the car. The suspension layout/design is not going to change. The company who makes the rear coil over in the RT4 will be making the front strut for BDR soon.

Jeff