Narrowbody vs. RS/ST?

[bbmar26]

In the middle of backdate/build and finalizing a few things, im pretty set on just a pure longhood narrowbody original 911 design but was curious how much performance i might be sacrificing by not having the wider wheelbase (and tires) that i could have if i went with RS or ST flares? Again pretty set on that original 911S looking car but just curious of others experiences, i know i can get the 7R wheels in the back to help make up the difference while keeping the narrowbody but just curious how it would stack up to the RS/ST configuration on the street and track? Thanks!

-Ben

[bgyglfr]

What are starting from? Is it flared already? I would say to stick with what came on your chassis.

[Charles Freeborn]

Generally bigger tires are a result of performance increases in the engine and suspension. IMHO putting fat tires on an otherwise stock car is silly. And yes, permanentlychanging from original will diminish value.

[bbmar26]

Starting with 75 base for the backdate, was thinking to just leave the stock flares ideally. But again it would be easy to put on steel RS flares but im just wondering how much more handling/performance that would bring over leaving it narrowbody? Would it be about the same?

[bgyglfr]

What are you planning for the engine? As said above, the cars typically got wider as the power increased. It wouldn't make sense to flare the car unless you are going to back it up in the engine compartment.

Personally, I would build around the tub you have. Welded body parts is much more difficult to reverse than bolt on parts (fenders etc).

In the end, it's about what you want. We can give opinions but, if you aren't happy, you will always second guess you decisions.

[bbmar26]

Going to be a 95 993 engine, so quite a bit of power in a light car which is why i was curious about going narrowbody with that vs giving it a bit more width in the back with RS flares etc. But i think in the end will just do the narrowbody still but was just curious of everyones experiences.

[enzoducoing]

Hello
Regardless of your plans for your car, which as stated, depends entirely up to what you like best, let me share some of my experiences with big-engined narrow-bodied and wide cars. All my cars have 3.8s in them pulling around 330hp on the wheels. Two of them are narrow bodied and two are wides. To be honest, the narrow cars when properly set-up and balanced are a to more fun to drive hard than the ones with the extra rubber. The torquey engines help up a lot to throw the chassis around and handle them with the throttle with ease because you find the limit easily predictable, whereas the wide cars with have a lot more grip tend to never let you see the limit until it's too late, they kind of give you a false sense of security. The down side to the narrow cars is that because of their absent aerodynamic panels and limited downforce, it gets hairy to drive at high very speeds, the front end starts to lift and you feel it float. The wide cars with front spoilers and tails get hunkered down the faster you drive and feel much more controlled at speed and fast wide turns. It all depends where and how you want to drive your car. If it is a fun canyon carver and twisty short track weapon, I recommend a narrow car. If you like to test the limits of aerodynamics and the local traffic authorities, as well as run in a long fast track, then a wide car is your ticket.
My narrow cars have 7X15 fuchs all around with 195/65/15 Bridgestone Potenza RE760 Sport and I've never felt the need for a wider tire, they handle beautifully.
Hope this helps you.
Cheers
MD

[bbmar26]

Great, thank you very much for that!

[gliding_serpent]

I agree on the power part. The more power, the more you may see in benefit from wider wheels. Otherwise, with a closer to stock engine, you are just adding drag and unsprung weight, which will make your car sluggish, but a great momentum car.

I did not backdate, but I kept my Carrera as a narrow body because it made sense with my goal to keep my car as light as possible (without going with fiberglass fenders, which tend to make the front too light relative to the back).

[Jamesrlong]

Not trying to high jack the thread but I think this will still stay on point. Anyone know what the widest rear that would fit on the back of a narrow body is?

[dnovick911]

The Fuchs on my '86 targa (15' x 7 / 8) offered more feel than the 17" Fox RSRs I'm now running on y '85 targa. But they sure look good, and definitely offer more grip. Definitely more of a sleeper with the narrow body, but I love the wide rear IROC look. Do what makes you happier.

[Jmorski]

You can squeeze a 16x7 in the rear, Harvey Weidman can make a custom wheel that starts as a 16x7 and add an inch to the inside to make it an 8. With this setup you can run a 225 tire on a narrow body car. It's a very tight fit so if you are planning on spacers to make room for brakes ect it won't work.

[benjoys02]

I have a '77 narrow body with a 3.0 stock motor. Stock flares upfront and SC rear flares. With 15x7 front and 8 rears, what's the widest NON-LOW profile tire one can use? I like the fenders filled vs. ones that show inner fender wells with low profile tires.

[Bill Verburg]

Originally Posted by bbmar26

Going to be a 95 993 engine, so quite a bit of power in a light car which is why i was curious about going narrowbody with that vs giving it a bit more width in the back with RS flares etc. But i think in the end will just do the narrowbody still but was just curious of everyones experiences.

You get demonstrably increased grip by using wider wheels, wider tires, and increasing track width.

How much grip is enough is more personal, some guys like to slide some want grip for better safety and lower lap times.

a 993 engine in an early chassis is going to exceed the grip envelope when pushed hard. If you like to slide, spin tires and counter steer stay w/ 6s and whatever tires will fit them. Try driving the stock car hard on a slick road for a little preview.

If not driving hard it makes little difference, the harder you drive the more difference it makes.

from a true narrow body w/ 4x 6Et36 and oe 185/70 x15 tires
+1
rear 7ET 49 +10-16mm spacer for up to a 225/50 x15 tire or use a 7ET 39-33 wheel and no spacer
++1 add 7ET23.3 w/ 205/50 x15 front

+2 add RS/Carrera rear flares
7ET23.3 205/50-55 x15 front and 8ET10.6 225/50 x14 rear
++2 change rear to 9x15ET12-15 & 245/45 x15 tire
+2 alternate use 16s
++2 alternate use 16s

+3 still w/ RS/Carrera rear flare
8x17Et25-30 225/45 & 9 ET12-15 255/40 x17
++3 use 9.5 ET18
+++3 use 245-245/40 x17 & 265/40 or 275/40 x17 on 8 & 9.5

+4
8x18ET25-30 225-245/35-40 & 9.5 ET19 265-275/30-35 x18

when I first put a 3.6 into my '76 Carrera3.0 I had the +2 set up for street and +++3 for track use, I have since settled on ++3 as the best all around setup w/ little to no track use on this car these days

+5
930 fenders
9 & 11 x15, 16,17,18 245-255 front and 285-315 rear

These set ups are fabulous for track use, overkill but great looking for street use

[bbmar26]

Thanks Bill! Yeah still debating but 95% set on the narrowbody route on this build, just something about that original design does it for me, i guess if its too much power in the long run i can do an engine swap down the line.

[gestalt1]

Another point is that tires have come a long way since the 70s. I would think a DOT R tire 205 width would have more grip than a 275 wide 70s tire.