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Official RTR Tech 7 Install Thread!

TwinReverb

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Looks killer! Are you lowered or are you still factory height? How does it ride and handle?
I am lowered on BMR Handiling springs (SP083R).

Just the new tires improved hading quite a bit. As far as improvement from just the wider wheels, I have not yet had a chance to to push the car real hard (rain). I upgraded the fronts from the 9.5 wheels after getting the extended studs so I could rotate. I do notice a little more bumpsteer with the wider wheels.
 

mikeyjobu

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Anybody notice tram-lining with these even in the rear? Mods are in my sig, so don't say it's cradle movement etc. I don't get any sort of noticeable tram-lining with the factory PP wheels which I run in colder seasons.

I'm just wondering if the aggressive 33mm offset is going to upset the suspension on track and make the car touchy or if the benefits of higher feedback will outweigh the occasional squirley behavior on not so great roads.

The scrub radius is quite a bit larger with that offset than the factory wheel off-set.

I run the factory PP wheels with BF Goodrich g-Force Comp 2 All seasons for cold season (factory staggered setup) and run Pilot Sport 4S's on the Tech 7's in the summer (4 square 19x9.5 setup).

Tire sizes are factory 255/40R19 and 275/40R19's on PP wheels and 275/40R19's on all 4 RTR Tech 7's.

BTW some one asked about tire size when I was scanning through this thread, 285/35R19's. I don't think that profile will provide any benefit on a 9.5 inch wheel over 275/40R19's and may even have inferior handling. Maybe on a 10 inch wide wheel it would.

Here's why, 9.5 is the MINIMUM rim width for that profile. And your side wall height is only shrinking by 5mm as opposed to a 40 series...that's not much.

When you run a tire at it's minimum rim width instead of it's "ideal" or "standard" rim width, the side wall angle is going to be less than optimal (bulged out) making the tire feel more mushy and less responsive. The opposite is true running it at max rim width, the side wall will be pre-loaded and make the tire overly edgy. That could be good on tires that are inherently mushy, but on a properly designed performance tire neither are ideal.

There's several auto x guys that run RE-71R's that have used both 285/35R19's and 275/35R19's (Re-71R's are not available in 275/40R19) and noted that they lost some response with the 285 despite gaining width and tad bit of diameter. Also running them on the minimum diameter wheel causes the outer shoulder blocks to curl over so your may actually loose contact patch area.

Tire rack used the "ideal" rim width for both 275 and 285 tread width measurements and a 275/40R19 will produce a slightly larger tread width in the same tire on a 19x9.5 than a 285/35R19. You'll get less than 10 with a 285/35 on a 9.5 rim as the standard size is 10 and that is the width most ideal for that profile.

Stuffing bigger tires on the rim than it's designed for (up-sizing) only makes sense if you can't get the proper size for your wheels in that particular tire and the benefits of that tire compound and tread design outweigh the losses of an improper size. Going outside of the specified rim width range will not only cause even greater performance issues, it can actually cause risk of the tire sliding off the rim under heavy loading = not good!

Most auto X guys use the RE-71R in 285/35R19 because it's not made in a proper 275/40R19 for the mustang's 19x9.5 rear's on PP cars for a 19x9.5 4 square setup, a common size wheel for this car. And you get more contact patch by using 285/35R19 (10.1 tread width) over 265/40R19 (9.3 tread width) on a 19x9.5 wheel which is the next closest size to fit even though 265/40R19's standard rim width is 9.5 for that tire.

It's all a balancing game :D. But anyway, back to the tram-lining question, has anyone used these on a track and how they perform compared to PP wheels? I have yet to get a chance to track it, but hope to towards the end of summer. Just looking to see what I should expect from them.

There are a few 285/40/19 tires out there -- I've been considering those -- even when discussing tread width, there are variations in the actual width of the tread: take a look at the 285/40/19 options -- the Porsche spec tires purportedly have more tread? I'm partly considering the 285/40/19 option because they'll still fit a 9.5" rim, and because I would rather take some gearing out of the final drive than effectively add more -- a '15 MT82 Performance Pack car (3.73's) could benefit a little from a taller tire...
 

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krishelnino

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Put 'em on back in the spring but had to wait for some good pics to post.

RTR Tech 7 Black 20x9.5
Continental DW 275/35ZR20
Eibach Pro Kit Lowering Springs

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Do you have spacers/extended studs at the front ?
 

TheDonSalami

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Anyone know if 275/35 front & 295/30 rear on 20s will cause any problems with a 1 inch or so lower? Should I size it down to 285/30 instead?
 

2morrow

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Anyone know if 275/35 front & 295/30 rear on 20s will cause any problems with a 1 inch or so lower? Should I size it down to 285/30 instead?
275/35 front & 295/30 rear on 20s will be just fine. Make sure your rears are 10.5's.
 

sw686blue

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Put 'em on back in the spring but had to wait for some good pics to post.

RTR Tech 7 Black 20x9.5
Continental DW 275/35ZR20
Eibach Pro Kit Lowering Springs

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Just stunning!!! Nice ride, man.
 

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stang9779

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@Paul@PKAUTODESIGN I'm looking at getting staggered 20's will they work on a bagged car? I want to be able to air out.
 
 




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