Slicks at the back

Help Support 7173Mustangs.com:

Higgins56

Well-known member
Joined
Jan 2, 2012
Messages
188
Reaction score
0
Location
Finland
My Car
1971 Mach 1 Fastback now with 503 CID 4 bolt block with AFR Bullit heads , Edelbrock Performer RPM AirGap intake and ProSystems carburettor 1050.
4 sp Toploader with 9" Wavetrac rear.
Caltracs and shocks at the rear.
Hi,

I ve been offered Hoosier 30/9-15 slicks for my Mach 1.

Would they fit ?

What offset /BS for the wheel would be recommended ?

 

Don C

Fords Forever
Joined
Jan 1, 2012
Messages
7,929
Reaction score
699
Location
Springfield, OR
My Car
1971 Mustang Sportroof M code
Yes, they would fit, they're the equivalent of a 225 width tire. 7-inch wheel with 4-inch backspacing.

A word of caution, our tires are typically around 25 or 26 inch diameter, a 30 inch tire will significantly increase your effective rear end ratio.

Another word, mixing bias and radial can cause handling problems.

My final, they won't be street legal.

 
Last edited by a moderator:

Higgins56

Well-known member
Joined
Jan 2, 2012
Messages
188
Reaction score
0
Location
Finland
My Car
1971 Mach 1 Fastback now with 503 CID 4 bolt block with AFR Bullit heads , Edelbrock Performer RPM AirGap intake and ProSystems carburettor 1050.
4 sp Toploader with 9" Wavetrac rear.
Caltracs and shocks at the rear.
Yes, they would fit, they're the equivalent of a 225 width tire. 7-inch wheel with 4-inch backspacing.

A word of caution, our tires are typically around 25 or 26 inch diameter, a 30 inch tire will significantly increase your effective rear end ratio.

Another word, mixing bias and radial can cause handling problems.

My final, they won't be street legal.
Hi Thanks a lot of this information.

Street legality is no problem if I can take the tyres inside ( I have folding back seat ) to the race track and change them there under the car.

These tyres would be for strips only.

 

Higgins56

Well-known member
Joined
Jan 2, 2012
Messages
188
Reaction score
0
Location
Finland
My Car
1971 Mach 1 Fastback now with 503 CID 4 bolt block with AFR Bullit heads , Edelbrock Performer RPM AirGap intake and ProSystems carburettor 1050.
4 sp Toploader with 9" Wavetrac rear.
Caltracs and shocks at the rear.
Yes, they would fit, they're the equivalent of a 225 width tire. 7-inch wheel with 4-inch backspacing.

A word of caution, our tires are typically around 25 or 26 inch diameter, a 30 inch tire will significantly increase your effective rear end ratio.

Another word, mixing bias and radial can cause handling problems.

My final, they won't be street legal.
Hi Thanks a lot of this information.

Street legality is no problem if I can take the tyres inside ( I have folding back seat ) to the race track and change them there under the car.

These tyres would be for strips only.
One thing more..

what tyre size you actually refer with 225 width tyre with 7 inch wheel ( not 17 " )????

Can you give an example of a tyre to grab your idea better !

Thanks

 

Don C

Fords Forever
Joined
Jan 1, 2012
Messages
7,929
Reaction score
699
Location
Springfield, OR
My Car
1971 Mustang Sportroof M code
You'll want wheels that are 15-inch diameter, 7 inches wide, and with a 4-inch backspacing.

The metric equivalent of that tire (if made) would be 225/85x15.


For drag racing you generally want a lower effective final drive ratio, for quicker launches and acceleration. The higher effective final drive ratio of that tire will slow (maybe even bog) your launches and acceleration.

 
Last edited by a moderator:
Joined
Apr 27, 2012
Messages
4,751
Reaction score
72
Location
Nashville, Tennessee
My Car
1973 Q code Mach 1
make a 30" cardboard template or two and look at your clearances. Depending upon ride height of your vehicle they may or may not fit. By Making templates and positioning them you can get a good idea of the necessary backspacing and clearances you have or need.

 

Finmach

Well-known member
Joined
Jul 10, 2012
Messages
241
Reaction score
2
Location
Finland
My Car
'72 Mach 1. Ford Racing 460+TKO600+Moser M9 4.11 DL
30x9-15

two possible way to read, diffrence comes by the usage of a tire.

Drag tire

30 = is the height of the tire

9 = thread width

15 = rim diameter

street tire

30 = is the height of the tire as above

9 = section width

15 = rim diameter as above

For example my M/T ET Drag tires #3056ST are made for drag racing. They are told to be 29.5x9-15. Their thread is 8.9" and the section widht is 11.4". According this my 29.5x9-15 drag tire equals 29.5x11.5-15 street tire.

Take a look from here:

First hoosier I was able to find, thread is 9" and section is 11.8", that equals 30x12-15 street tire.

http://www.summitracing.com/int/parts/hoo-18209

here's similar tires as my Mach 1 uses:

http://www.summitracing.com/int/parts/mtt-3056st

Just food for thoughts.

 

Finmach

Well-known member
Joined
Jul 10, 2012
Messages
241
Reaction score
2
Location
Finland
My Car
'72 Mach 1. Ford Racing 460+TKO600+Moser M9 4.11 DL
30x9-15

two possible way to read, diffrence comes by the usage of a tire.

Drag tire

30 = is the height of the tire

9 = thread width

15 = rim diameter

street tire

30 = is the height of the tire as above

9 = section width

15 = rim diameter as above

For example my M/T ET Drag tires #3056ST are made for drag racing. They are told to be 29.5x9-15. Their thread is 8.9" and the section widht is 11.4". According this my 29.5x9-15 drag tire equals 29.5x11.5-15 street tire.

Take a look from here:

First hoosier I was able to find, thread is 9" and section is 11.8", that equals 30x12-15 street tire.

http://www.summitracing.com/int/parts/hoo-18209

Tire Diameter: 29.50 in.

Section Width: 11.80 in.

Tread Width: 9.00 in.

Minimum Recommended Wheel Width: 8.00 in.


Maximum Recommended Wheel Width: 10.00 in.


With drag tires you don't want to run with 7" wide wheels, 15 x 9 wheel would be a perfect match.

here's similar tires as my Mach 1 uses:

http://www.summitracing.com/int/parts/mtt-3056st

Just food for thoughts.

 
Joined
Apr 27, 2012
Messages
4,751
Reaction score
72
Location
Nashville, Tennessee
My Car
1973 Q code Mach 1
on a 9" rim you will probably need 5.25 back spacing. My current rear tires are 28.5 inches tall and just a bit wider than what you are considering. At the front of the wheel well I had to cut and move the inner fenderwell to make room for my tires to fit.

I would definitely recommend you do some sort of mock up before buying rims and tires that size.

 

Paul of MO

Well-known member
Joined
Jul 2, 2011
Messages
615
Reaction score
8
Location
Land of old Geezers
My Car
71 M Code Convert - Barn find
73 H Code Convert - Field find
73 H code - Latest Project
Slicks are sticky - Drag Strips are sticky - Your car hooks up like it never has before and something goes "snap".

I am not saying not to do it - I am saying trailer the car to the track and have fun and if "snap" happens you are not stranded.

We had a gentleman at that always brought an empty trailer to the track down in Jupiter Fl. Every Saturday he got paid pretty well to haul someone home.

I would race it a few times with street tires if you have never done it before.

- Paul of MO

 

Higgins56

Well-known member
Joined
Jan 2, 2012
Messages
188
Reaction score
0
Location
Finland
My Car
1971 Mach 1 Fastback now with 503 CID 4 bolt block with AFR Bullit heads , Edelbrock Performer RPM AirGap intake and ProSystems carburettor 1050.
4 sp Toploader with 9" Wavetrac rear.
Caltracs and shocks at the rear.
Slicks are sticky - Drag Strips are sticky - Your car hooks up like it never has before and something goes "snap".

I am not saying not to do it - I am saying trailer the car to the track and have fun and if "snap" happens you are not stranded.

We had a gentleman at that always brought an empty trailer to the track down in Jupiter Fl. Every Saturday he got paid pretty well to haul someone home.

I would race it a few times with street tires if you have never done it before.

- Paul of MO
THank you all gentlemen !

You have brought good views to master the thing.

I try first with some wheel/ tyre combinations and try to estimate the right combination in my case ( the back axle is not a standard 9" which brings another interesting element to this case). I wonder if somebody can recognize what it is. It is attached with a Detroit locker.

IMAG0682.jpg

 

Higgins56

Well-known member
Joined
Jan 2, 2012
Messages
188
Reaction score
0
Location
Finland
My Car
1971 Mach 1 Fastback now with 503 CID 4 bolt block with AFR Bullit heads , Edelbrock Performer RPM AirGap intake and ProSystems carburettor 1050.
4 sp Toploader with 9" Wavetrac rear.
Caltracs and shocks at the rear.
Hard to tell without a better picture of the carrier, but I think you might have a Lincoln 9 3/8 rear end in your car. It might just be an aftermarket housing like Speedway, Currie and a bunch of others sell.
Thanks again of your comment.

How can I check it further from oitside ?

What could bebthe ratio - with 3000rpm the car runs 60 mph on the 4th gear.

seems that the rear end is sturdy enough for my use.

Meanwhile I tested M/T's 28/10.5-15 tyres with Billetspecialties wheel combination which came available near by and it seems to fit nicely. There is half an inch space to the leaf spring and the tyre keeps nicely within the rear fender.

30" tyre would mean a lot of work to fit it there...

With this wheels offset I need to add a 1" spacer but thats it !

IMG_1156.JPG

IMG_1157.JPG

IMG_1158.JPG

 
Joined
Apr 27, 2012
Messages
4,751
Reaction score
72
Location
Nashville, Tennessee
My Car
1973 Q code Mach 1
can you get a picture of the carrier from the front?

I suspect you'll have the tire hit the fenderwell when the suspension compresses as you are currently set up. Spacing outward is going to make it worse.

I hope your leaf springs are stiff as hell. You might want to fabricate some beefy bump stops.

 

Higgins56

Well-known member
Joined
Jan 2, 2012
Messages
188
Reaction score
0
Location
Finland
My Car
1971 Mach 1 Fastback now with 503 CID 4 bolt block with AFR Bullit heads , Edelbrock Performer RPM AirGap intake and ProSystems carburettor 1050.
4 sp Toploader with 9" Wavetrac rear.
Caltracs and shocks at the rear.
can you get a picture of the carrier from the front?

I suspect you'll have the tire hit the fenderwell when the suspension compresses as you are currently set up. Spacing outward is going to make it worse.

I hope your leaf springs are stiff as hell. You might want to fabricate some beefy bump stops.
The photo shows you the installation WITH the one inch spacer already.

The leaf springs are Calverts split mono leaf + Caltracs + Calvert adj. shocks

I try to get a photo from the front.

 

Finmach

Well-known member
Joined
Jul 10, 2012
Messages
241
Reaction score
2
Location
Finland
My Car
'72 Mach 1. Ford Racing 460+TKO600+Moser M9 4.11 DL
1" spacers, Plus 400hp & bb torque, manual, drag slicks... Are you using pro spacer style spacers which are bolted in or are you running 3" studs? I am not feeling comfortable with the spacers, slicks and strip combination. Might work and can also rip the studs out of aluminum spacer.

Driveshaft safetyloops can be welded from a round profile pipe and have them welded between the front frames and same to rear depends too how the frames are connected. Friend of mine did similar setup from chromemoly to his '73 Mach1 and it came pretty good. He lives at Ylojarvi I can arrange you a garage visit if you want to.

 

Lake

Well-known member
Joined
Jul 9, 2013
Messages
75
Reaction score
1
Location
Finland, Europe
My Car
1972 Fastback
here is 28x12.5" with 10" wheel. Flares are rolled though...



here is 28x12.5" with 10" wheel. Flares are rolled though...
1040044_10151449018166744_877374030_o.jpg

 
Last edited by a moderator:

Paul of MO

Well-known member
Joined
Jul 2, 2011
Messages
615
Reaction score
8
Location
Land of old Geezers
My Car
71 M Code Convert - Barn find
73 H Code Convert - Field find
73 H code - Latest Project
1" spacers, Plus 400hp & bb torque, manual, drag slicks... Are you using pro spacer style spacers which are bolted in or are you running 3" studs? I am not feeling comfortable with the spacers, slicks and strip combination. Might work and can also rip the studs out of aluminum spacer.

Driveshaft safetyloops can be welded from a round profile pipe and have them welded between the front frames and same to rear depends too how the frames are connected. Friend of mine did similar setup from chromemoly to his '73 Mach1 and it came pretty good. He lives at Ylojarvi I can arrange you a garage visit if you want to.
Have someone look at the spacers and studs and give you a safety opinion. I would not race this car this way. If you snap the studs off you can imagine what might happen next. You do not want to hurt yourself or anyone else.

Paul of Mo

 

Higgins56

Well-known member
Joined
Jan 2, 2012
Messages
188
Reaction score
0
Location
Finland
My Car
1971 Mach 1 Fastback now with 503 CID 4 bolt block with AFR Bullit heads , Edelbrock Performer RPM AirGap intake and ProSystems carburettor 1050.
4 sp Toploader with 9" Wavetrac rear.
Caltracs and shocks at the rear.
1" spacers, Plus 400hp & bb torque, manual, drag slicks... Are you using pro spacer style spacers which are bolted in or are you running 3" studs? I am not feeling comfortable with the spacers, slicks and strip combination. Might work and can also rip the studs out of aluminum spacer.

Driveshaft safetyloops can be welded from a round profile pipe and have them welded between the front frames and same to rear depends too how the frames are connected. Friend of mine did similar setup from chromemoly to his '73 Mach1 and it came pretty good. He lives at Ylojarvi I can arrange you a garage visit if you want to.
Hi,

I am thinking of Eibach Pro Spacers...

A garage visit to your friend would be great. I will call you.



here is 28x12.5" with 10" wheel. Flares are rolled though...



here is 28x12.5" with 10" wheel. Flares are rolled though...
Hi

with a standard car ( without flare opening) 10.5 " may be the maximum width with a proper wheel offset ?

 
Last edited by a moderator:
Top