This is the next big question I have to submit to the 914world.com, non club, brain trust. =-)

I have two 225/50/15's for the front. 8.5" wide. +/-
I have two 285/40/15's for the rear. 10.5" wide. +/-

The fronts fit fine with no spacers.

The rear backspacing is OK but the fenders will need modification.

The big question is do i mod the stock fenders out 2"s and no wheel spacers or install the sheridan flares and space the wheels out to meet the FG fenders????????

I'm wondering if anyone has experienced noteable handling gains by going wider on the rear???

Inquiring minds want to know.

Roger

generally speaking, the wider you go in the back, the more the front will "push", not a good thing, you want to get the front and rear closer with respect to overall width.....

wow . what size tire would you carry for a spare?

k

QUOTE

mod the stock fenders out 2"s and no wheel spacers, or install the sheridan flares and space the wheels out to meet the FG?

No question, I would much rather stretch the rear sheet metal than add wide fiberglass flares with backspacing to fill the gap.

AAA card for a spare...

Where are you going to stick the 10" wide wheel you took off?

BJH

bolt a rear trunk luggage rack to the targa top. sorry for the hijack.

k

so mike, the best handling layout is to keep all 4 tires about the same width??? i ask only because the turbo carreras and others do go wider in the rear and i wasn't sure if it makes that big of a difference.

I really wanted to ask someone who has done the spacers in the rear and had some real track time to respond.

i noted that one of our top AX drivers used the wider rear stance and figured that might be better.

I'm not even going to try to fit into any "class" as my 914 is a V8. i will be AXing purely for the fun of it.

QUOTE (rogergrubb @ Jan 23 2006, 05:24 PM)

so mike, the best handling layout is to keep all 4 tires about the same width??? i ask only because the turbo carreras and others do go wider in the rear and i wasn't sure if it makes that big of a difference. I really wanted to ask someone who has done the spacers in the rear and had some real track time to respond. i noted that one of our top AX drivers used the wider rear stance and figured that might be better. I'm not even going to try to fit into any "class" as my 914 is a V8. i will be AXing purely for the fun of it.

totally different cars...no comparison as all

the 911's need the larger rear wheels and track due to the heavy @ss with the motor hanging back there.....

I had a car with a locked diff (welded) and a wider track on the rear by 4 inches.

I had a 180hp type 4 motor...

It was ok, I had to goose the throttle and get the rear wheels to let go on the really tight corners.

With a V8 it should not be a problem to get the rear wheels to let go if needed.

I would offer this.

a) It will look cool
It will grab better during takeoff.
c) it will look cool
d) it will push, but with the right tires on the front, you will have fun.
e) it will look cool

Rich

I used to run wider tires on the rear of my Mustang to compensate for throttle induced oversteer. It worked, but led to extreme understeer in normal situations, which sucked. I have since gone back to the same size tires all the way around, and learned to keep my foot out of it while in the middle of a turn. It actually corners much better this way. Of course a 914 is a different animal, and some of it just comes down to preference and driving style.

QUOTE (rogergrubb @ Jan 23 2006, 05:24 PM)

so mike, the best handling layout is to keep all 4 tires about the same width??? i ask only because the turbo carreras and others do go wider in the rear and i wasn't sure if it makes that big of a difference. I really wanted to ask someone who has done the spacers in the rear and had some real track time to respond. i noted that one of our top AX drivers used the wider rear stance and figured that might be better. I'm not even going to try to fit into any "class" as my 914 is a V8. i will be AXing purely for the fun of it.

yeamans tube frame car has a track more equal front to back....it's "easier" to mount bigger rear tires and wheels and yes, some people need the extra rubber for the power the car puts out,...adding equal size fronts is harder to steer (that is why some people have been going with powersteering)

you are more likely to understeer with the rear tires sticking out way more than the fronts....of course for lite duty auto-x'n, you might never be able to tell the difference.......

on my 911, I currently have 255's on 9's in the rear (225 on 8's up front), from every single place I've asked, simply switching to 275's in the rear will induce understeer more quickly due to the rear having more grip....adding spacers to the rear would do the same thing since the "arc" the wheels follow thru a corner will be different

I guess with a high powered 914 you will also drive it differently - more like a 911. With my 911 on an AX course you really have to throttle steer it to get it around sharp corners.

A yup what they said. However with more Horsepower and torque you may need the extra rubber to be able to put the power down.

You will have to relearn how to get the car to rotate in a AX type turn. Should go something like this:

Scream in to the gate brake hard in straight line which will transfer the weigh to the front. trail brake as you turn in and roll on the gas as much as you can. You don't want the front to push so you may not be able to put much throttle down till you are pointing in the direction you want. Then get the wieght transfered to the back as you nail it off the exit.

QUOTE (Joe Ricard @ Jan 23 2006, 05:59 PM)

A yup what they said. However with more Horsepower and torque you may need the extra rubber to be able to put the power down.

he is going to run the same size rubber, he wants to move the rear wheels outboard further with spacers.....I say all it'll do is make the car wider with no real benifit if keeping the front narrow

but it will look cool! and that is important...more to some and less to others...

QUOTE (r_towle @ Jan 23 2006, 06:07 PM)

but it will look cool! and that is important...more to some and less to others...

yea, if you like that Chevy Dually truck look

road course car, ran spacers and 9in rims on the back. larger tires and all the good stuff.

I then put 225's all around on 8's. small spacers up front.. No noticeable loss of speed. Good turn in, didn't loose the ass end.

Low seat time on this but I was happy. More track up front and penty of rubber up front!!!

Autox, I suck so ask someone else but I would image understeer could be an issue.

QUOTE (d914 @ Jan 23 2006, 07:15 PM)

road course car, ran spacers and 9in rims on the back. larger tires and all the good stuff. I then put 225's all around on 8's. small spacers up front.. No noticeable loss of speed. Good turn in, didn't loose the ass end. Low seat time on this but I was happy. More track up front  and penty of rubber up front!!! Autox, I suck so ask someone else but I would image understeer could be an issue.

yes, between the comment above about plenty of rubber to hang on with and having a V8 behind me... with stock tires i noticed the added weight towards the rear made for some pronounced over steer. a little too much. then tapping the throttle brought the rear right around. tons of torque....

after i burn up the pirelli 225's up front the goal will be to get some front DOT stickies.

then, after using up the rear rubber, work the logistics for a larger wheel diameter and tire for the rear. (next to impossible to get 15" performance fatties like the 285)

i guess i'll go with the flared steel option. and just use up the rear rubber and by then be able to afford new rear wheels/tires . =-)

thanks everyone!!!

so no ones' got any data to prove that going wider in the rear can benefit a V8???

QUOTE (rogergrubb @ Jan 23 2006, 06:45 PM)

(next to impossible to get 15" performance fatties like the 285)

i've been looking for 285/40 x 16 tires for over a year now!

care to share where you got yours and what brand they are ???
Andy

QUOTE (SirAndy @ Jan 23 2006, 07:59 PM)

QUOTE (rogergrubb @ Jan 23 2006, 06:45 PM) (next to impossible to get 15" performance fatties like the 285) i've been looking for 285/40 x 16 tires for over a year now! care to share where you got yours and what brand they are ??? Andy

Florida/Pirelli. =-) They don't sell them anymore.

QUOTE (rogergrubb @ Jan 23 2006, 06:45 PM)

so no ones' got any data to prove that going wider in the rear can benefit a V8???

yes, it will benefit the fact that it will be harder for you to spin the rear tires, which is plenty gud in a v8 914 as you don't want to spin the rear while you're in anything BUT a straight line ...

as for the overall balance, a large difference in tiresize rear/front will throw off your otherwise good 50/50 balance of the car.
with much bigger tires in the rear you will add massive understeer in corners. you *can* compensate for that with bigger torsion bars and a BIG sway bar.

it's all in the (corner) balance.
Andy

QUOTE (rogergrubb @ Jan 23 2006, 07:02 PM)

QUOTE (SirAndy @ Jan 23 2006, 07:59 PM) QUOTE (rogergrubb @ Jan 23 2006, 06:45 PM) (next to impossible to get 15" performance fatties like the 285) i've been looking for 285/40 x 16 tires for over a year now! care to share where you got yours and what brand they are ??? Andy Pirelli. =-)

Pirelli hasn't made that size in 15 years!

if you got those tires "new" make sure they're still soft as they must have been sitting on someones shelf for over a decade ...

QUOTE (SirAndy @ Jan 23 2006, 08:02 PM)

QUOTE (rogergrubb @ Jan 23 2006, 06:45 PM) so no ones' got any data to prove that going wider in the rear can benefit a V8??? yes, it will benefit the fact that it will be harder for you to spin the rear tires, which is plenty gud in a v8 914 as you don't want to spin the rear while you're in anything BUT a straight line ... as for the overall balance, a large difference in tiresize rear/front will throw off your otherwise good 50/50 balance of the car. with much bigger tires in the rear you will add massive understeer in corners. you *can* compensate for that with bigger torsion bars and a BIG sway bar. it's all in the (corner) balance. Andy

i'm sorry, i didn't mean wider rubber in the rear, i mean wider stance via spacers in the rear.... whoops.

QUOTE (rogergrubb @ Jan 23 2006, 07:05 PM)

i'm sorry, i didn't mean wider rubber in the rear, i mean wider stance via spacers in the rear.... whoops.

wider stance through spacers won't give you more traction.
if balanced with the front (bigger torsion bars, large sway bar) a wider track *will* improve handling ...

the wider the better, *if* balanced with the front ...

mueller mentioned scotts race car. it actually has a wider track in the *FRONT* ...
Andy