Fuel Safe Systems

Visit our community sponsor

Thanks Thanks:  1
Likes Likes:  5
Results 1 to 24 of 24

Thread: Wheels and tires

  1. #1
    Junior Member
    Join Date
    Oct 2018
    Posts
    5
    Post Thanks / Like

    Wheels and tires

    Hello, I have placed my order for a complete MK4 kit. I am getting ready to make final changes and final payment this week. Im having trouble deciding between 17 and 18 wheels. I like the look of the bigger ones but, if there is a big difference in ride quality I will gladly take the 17 wheels. If anyone has any experience with this, your input would be appreciated. Thanks.

  2. Likes Drezx6r liked this post
  3. #2

    Steve >> aka: GoDadGo
    GoDadGo's Avatar
    Join Date
    Feb 2015
    Location
    Slidell, Louisiana
    Posts
    3,424
    Post Thanks / Like
    Blog Entries
    1
    Vince,

    The taller the side wall of the tire the better the ride will be, but not all MK-4's are created equal.
    15" tires, 235/60-15's and 295/50-15's will give you the most period correct look with the tallest sidewall possible; however, tire choice is limited.
    Also, two of my pals have the 18" wheels on their cars while I'm running 17's but the car with the best ride quality has a very heavy 390 FE with the IRS set up.
    Shown below is my car which sports a 3-Link rear end set up with 245/45-17's up front with 285/40-17's out back.

    https://youtu.be/CaRlqMmKIzk

    I chose this combination because this was the tallest of the 17" tires that I could run in an attempt to mimic the more period correct look of the 15" wheels.
    Good Luck From The Dark Dart Side & I Hope This Helps!

    Steve
    Last edited by GoDadGo; 05-12-2019 at 08:31 PM.

  4. #3
    Junior Member
    Join Date
    Oct 2018
    Posts
    5
    Post Thanks / Like
    Thanks! I’ve been sure about every choice on this car so far. I’m just on the fence with this one thing. This car will have IRS and a small block 427. Great looking car by the way!

  5. #4

    Steve >> aka: GoDadGo
    GoDadGo's Avatar
    Join Date
    Feb 2015
    Location
    Slidell, Louisiana
    Posts
    3,424
    Post Thanks / Like
    Blog Entries
    1
    Quote Originally Posted by Vince C View Post
    Thanks! I’ve been sure about every choice on this car so far. I’m just on the fence with this one thing. This car will have IRS and a small block 427. Great looking car by the way!
    Thanks for the complement.

    Also, you can save a bunch of money on your engine because the 427 is way, way, way too much power for these cars.
    The sweet spot is around 350 HP with torque figures in the same realm so you may want to reconsider the 427 inch engine.
    For the record my 383 makes about 450 HP with similar torque figures and it will spin the tires at will in 1st, 2nd and 3rd.
    This is with the rev-limiter set at a stupid low 4,300 RPM, but my operation range is between 2,000 and 6,300 RPM.

    Good Luck & Take A Look At Edwardb's two MK-4 build threads because they will really help you.

    SBF Build Solid Axle (5 Link) Thread:
    https://thefactoryfiveforum.com/show...rogress-Update

    Coyote IRS Build Thread:
    https://thefactoryfiveforum.com/show...iversary-Build

    His Work Is Phenomenal & He Truly Knows These Cars Better Than Most Of Us!
    Last edited by GoDadGo; 05-12-2019 at 09:00 PM.

  6. #5
    Senior Member edwardb's Avatar
    Join Date
    Feb 2011
    Location
    Lake Orion, Michigan
    Posts
    6,060
    Post Thanks / Like
    GoDadGo (Steve) thanks for the shout-out. Again. Those threads just keep on giving.

    Vince C I've had builds with 17-inch wheels and Nitto 555's and 18-inch wheels with Goodrich Rival's. I can honestly say there was little/no difference that I could attribute to the tires. The one with the 18's (#8674 Anniversary build) has the better ride. But it's also the one with IRS. Which is what I attribute the difference to. Note everyone will agree with me. But based on my experience with both, I wouldn't make a wheel choice between these two over ride concerns alone. I'm saying you probably wouldn't tell the difference. Other factors to consider? Today there are more 17-inch tire choices than 18-inch. And what 18's are out there cost more. But based on the industry, where bigger wheels are the norm, don't expect it will always be that way. Also depends on your brake selections and what wheels those fit. Also depends on your personal taste. The 18's do look slightly bigger. But it's very subtle and unless you had to two next too each other, you probably wouldn't notice that difference.
    Build 1: Mk3 Roadster #5125. Sold 11/08/2014.
    Build 2: Mk4 Roadster #7750. Sold 04/10/2017. #7750 Build Thread
    Build 3: Mk4 Roadster 20th Anniversary #8674. 03 of 20. 2015 crate Coyote, 2015 IRS. Legal 04/18/2017. #8674 Build Thread and Video
    Build 4: Gen 3 Type 65 Coupe #59. Gen 3 crate Coyote. Delivered 12/2/2017. #59 Coupe Build Thread

  7. #6
    Senior Member
    Join Date
    Aug 2012
    Location
    Grand Rapids, MI
    Posts
    298
    Post Thanks / Like
    Vince,

    It may be beneficial to research tire makes, models and sizes prior to ordering or committing to a wheel. Not all tire versions are available in all sizes. Deciding on how you'll use the car may guide you towards one style/brand over another.

    As EdwardB indicated there probably isn't a great difference in ride quality between the 17 & 18s once you get the air pressure set right (mid 20s to start). I'm a fan of larger rear tires, 315s are popular but not available in all versions. My plan is for 335s but it may take a few custom touches.

    But I tend to disagree with GoDadGo on HP/Torque. I've run a 427W at 440 RWHP and think it's about right. I'm planning on the same engine for my current build with a power increase and less weight than my previous cars. But I make no claims to being "normal". Learn how the skinny pedal works.

    Always happy to help another 427W brother and welcome to the site.

    Jim

  8. Likes Drezx6r liked this post
  9. #7
    Junior Member
    Join Date
    Oct 2018
    Posts
    5
    Post Thanks / Like
    Great, thanks you guys for the advice. I’m leaning towards the bigger wheels. That could change by tomorrow though.

  10. #8

    Steve >> aka: GoDadGo
    GoDadGo's Avatar
    Join Date
    Feb 2015
    Location
    Slidell, Louisiana
    Posts
    3,424
    Post Thanks / Like
    Blog Entries
    1
    The cool part of this forum is that all opinions are welcome so Jim probably likes going faster than me, likely a lot faster.

    What ever engine you choose will be great, just know that banker in me tries to save money every where possible and 427's can get expensive. Also, remember to take into account your rear end and transmission gearing since this will have a lot to do with your ability to spin the rear wheels.

    550 Torq X 3.23 Rear = 1776.50
    476 Torq X 3.73 Rear = 1776.48

    With that said you may want to consider going with the soft tire compound (100 - 200 Tread Wear) if you are going to go with a big inch engine. In addition, consider setting up a little spread sheet to make sure that your final gearing is where you'd like to be at whether you are cruising down the highway or at big end of the drag strip. I'm geared for 6,000 RPM at 124.42 MPH in 4th gear or 1,700 RPM at 70.51 MPH in 6th.

    Good Luck From The Dark O.C.D. Side!
    Last edited by GoDadGo; 05-13-2019 at 10:24 AM.

  11. #9
    Senior Member
    Join Date
    Nov 2017
    Posts
    465
    Post Thanks / Like
    Quote Originally Posted by GoDadGo View Post

    550 Torq X 3.23 Rear = 1776.50
    476 Torq X 3.73 Rear = 1776.48

    You do realize that you're eating all that gain up in friction losses with the majority of that being heat generated in the rearend in fourth gear (1:1 4th "gear" lockup on *most* common transmissions)?

    And in 3rd gear you're actually putting less HP+ TQ to the ground than in 4th (with those additional frictional losses generating heat in the transmission)?


    Just food for thought or discussion.

  12. #10

    Steve >> aka: GoDadGo
    GoDadGo's Avatar
    Join Date
    Feb 2015
    Location
    Slidell, Louisiana
    Posts
    3,424
    Post Thanks / Like
    Blog Entries
    1
    Quote Originally Posted by mike223 View Post
    You do realize that you're eating all that gain up in friction losses with the majority of that being heat generated in the rearend in fourth gear (1:1 4th "gear" lockup on *most* common transmissions)?

    And in 3rd gear you're actually putting less HP+ TQ to the ground than in 4th (with those additional frictional losses generating heat in the transmission)?


    Just food for thought or discussion.
    Mike,

    I was trying to illustrate the of torque multiplication effect between the 3.23 and 3.73 rear end ratios.

    Steve

  13. #11
    Senior Member
    Join Date
    Nov 2017
    Posts
    465
    Post Thanks / Like
    Got it.

  14. #12
    Senior Member BEAR-AvHistory's Avatar
    Join Date
    May 2015
    Location
    Raleigh NC USA
    Posts
    859
    Post Thanks / Like
    Ride quality is kind of personal. What is good for me might be harsh/soft, pick one, for you. In my case my wife, 75 years old, has no issues riding in the COBRA. Stock FFR coil overs, TKO-600, 3 link - 3:55 rear, 17" NITTO 555R 245X45X17 & 315X35X17 @ 21/22PSI 3-7/8" ride height. Ending useful life. will replace with NITTO NT01 255X40X17 & 315X35X17.
    Kevin
    MKIV #8234
    Coyote '13/TKO-600
    Delivered 2/7/14 - Plate "COYOTE NC1965" 3/25/15

  15. Likes SSNK4US liked this post
  16. #13
    Junior Member
    Join Date
    Feb 2019
    Location
    Oshawa, Ontario, Canada
    Posts
    24
    Post Thanks / Like
    Whats the widest tire you can do on the rear if you go with the 17" rims?

  17. #14
    Junior Member
    Join Date
    Feb 2018
    Posts
    28
    Post Thanks / Like
    Correct math on torque x gear.

    Just rambling here..

    850hp with 3.73 gears with 18" Kumho 285/30-18 and winning Goodguys in AutoX ... The car was CSX 3170.

  18. #15
    Senior Member
    Join Date
    Nov 2017
    Posts
    465
    Post Thanks / Like
    Quote Originally Posted by Jcdata View Post
    Correct math on torque x gear.

    Just rambling here..

    850hp with 3.73 gears with 18" Kumho 285/30-18 and winning Goodguys in AutoX ... The car was CSX 3170.

    Welcome to a driver or owner of the SCCA SOLO National Championship CAM-S car of 2015.

    Page 56 here:

    https://dk1xgl0d43mu1.cloudfront.net...pdf?1444922039


    I'm certain I'd like to hear more.

  19. #16
    Senior Member SSNK4US's Avatar
    Join Date
    Jul 2016
    Location
    Bakersfield, CA
    Posts
    325
    Post Thanks / Like
    Quote Originally Posted by Drezx6r View Post
    Whats the widest tire you can do on the rear if you go with the 17" rims?
    Not really sure of the widest.... but the 315/35r17 that FFR recommends and sells as a package is actually one wide tire!
    My M3 with competition package only has 265’s in the back. 2018 Vette Z51 package only (lol only?) has 285’s The new 2019 Vette has 335’s. Those are huge, and only 20mm (roughly 3/4”) wider than FFR 315’s
    Just my 2

    Kurt
    If everything seems under control, youre just not going fast enough....

    Build thread

    MKIV complete kit # 9395 delivered 7/31/18

  20. Likes Drezx6r liked this post
  21. #17
    Senior Member BEAR-AvHistory's Avatar
    Join Date
    May 2015
    Location
    Raleigh NC USA
    Posts
    859
    Post Thanks / Like
    What SSNK4US said about 315X35X17:





    The floor tiles are 12"X12". That's about 2 feet of tire rubber side to side. Good fit no rubbing on standard FFR suspension components & wheels. Tires are inside the wheel wells at the top.
    Last edited by BEAR-AvHistory; 05-14-2019 at 09:05 AM.
    Kevin
    MKIV #8234
    Coyote '13/TKO-600
    Delivered 2/7/14 - Plate "COYOTE NC1965" 3/25/15

  22. Likes Drezx6r liked this post
  23. #18
    Junior Member
    Join Date
    Feb 2019
    Location
    Oshawa, Ontario, Canada
    Posts
    24
    Post Thanks / Like
    Quote Originally Posted by BEAR-AvHistory View Post
    What SSNK4US said about 315X35X17:





    The floor tiles are 12"X12". That's about 2 feet of tire rubber side to side. Good fit no rubbing on standard FFR suspension components & wheels. Tires are inside the wheel wells at the top.
    Quote Originally Posted by SSNK4US View Post
    Not really sure of the widest.... but the 315/35r17 that FFR recommends and sells as a package is actually one wide tire!
    My M3 with competition package only has 265’s in the back. 2018 Vette Z51 package only (lol only?) has 285’s The new 2019 Vette has 335’s. Those are huge, and only 20mm (roughly 3/4”) wider than FFR 315’s
    Just my 2

    Kurt
    thank you both, 315 looks great BEAR. I wish my 15 Stingray had wider.
    Last edited by Drezx6r; 05-14-2019 at 06:24 PM. Reason: grammer

  24. Thanks BEAR-AvHistory thanked for this post
  25. #19
    Junior Member
    Join Date
    Oct 2018
    Posts
    5
    Post Thanks / Like
    Great info, thanks everyone. I went with the 18”. The kit is ordered and payed for. Can’t wait to get started!

  26. #20
    Senior Member SSNK4US's Avatar
    Join Date
    Jul 2016
    Location
    Bakersfield, CA
    Posts
    325
    Post Thanks / Like
    Congrats Vince! Now the waiting game begins. Hopefully time will fly!
    More details on your order? Building your own motor? Blueprint? Forte? Etc etc etc lol

    Kurt
    If everything seems under control, youre just not going fast enough....

    Build thread

    MKIV complete kit # 9395 delivered 7/31/18

  27. #21
    Junior Member
    Join Date
    Oct 2018
    Posts
    5
    Post Thanks / Like
    I’d love to build my own motor, it’s just so hard to beat the crate motors. I ordered the complete kit with IRS and Wilwood brakes. It gets a heater for my wife. It will get a small block 427 and a Tremec 6 speed.

  28. #22
    Senior Member SSNK4US's Avatar
    Join Date
    Jul 2016
    Location
    Bakersfield, CA
    Posts
    325
    Post Thanks / Like
    Cool! Looking forward to hearing more when you get going.

    Kurt
    If everything seems under control, youre just not going fast enough....

    Build thread

    MKIV complete kit # 9395 delivered 7/31/18

  29. #23
    Junior Member
    Join Date
    Nov 2017
    Posts
    5
    Post Thanks / Like
    Quote Originally Posted by Vince C View Post
    I’d love to build my own motor, it’s just so hard to beat the crate motors. I ordered the complete kit with IRS and Wilwood brakes. It gets a heater for my wife. It will get a small block 427 and a Tremec 6 speed.
    Congratulations! I also did IRS along with the Wilwood Brakes. I am about a month away from being road legal. Everything about the car is seriously BA, enjoy it!

  30. #24
    Senior Member Avalanche325's Avatar
    Join Date
    Nov 2011
    Location
    Jax Beach, FL
    Posts
    1,240
    Post Thanks / Like
    Congrats.

    The heater for your wife is a good idea no matter where you live. I am in Florida and use mine quite a bit. I also recommend heated seats. A lot of events, cruises, autocross, track days, etc require an early morning start. A heater makes a huge difference during those early morning runs in the winter. Also good for late night returns.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Breeze

Visit our community sponsor