Alright, quick rundown of setup. Front 235/45/17 rear 315/35/17. Front and rear QA1 coilover conversion. Wanting to eventually get wider front wheels and tires for better turning grip at least 265 preferably 285+. My question is if in the mean time I use a 1" bolt on adapter up front will this improve or simulate a little by widening the front stance? Essentially running flush with the fender. Is this logic/thinking all off or will this work for the time being. Thanks

 

With 17's you will likely be limited to 275's, possibly 285's without fender mods.

I'm sure larger will fit, but your coil overs will severely limit the available space without them sticking out. Ditch the coil overs & you can get some more room.

You do need a wider stance as you are basically increasing leverage on the suspension, decreasing spring rate etc.

 

Now will the clearance concerning the coilovers be an issue even though its an all tubular front end (K member and a arms) id have to change out the a arms to replace the coilovers. I appreciate the advice but my main question was will adding 1" bolt on spacers to the 235 benefit at all by essentially widening the stance 2" or am I better off just leaving it the way it is until I can get a wider wheel. Hope that makes sense.

 

I mistyped the answer in the last sentence of my previous reply...

You DON'T need a wider stance as you are basically increasing leverage on the suspension, decreasing spring rate etc. This does nothing for handling & in fact unfavorably changes the suspension geometry.

Spend your money on something useful instead of spacers.

The coil overs will contact the tires at the top sidewall area if you set the tires inboard.
Typically the more inboard you can get a wide set of tires the better for geometry purposes.

 

Gotcha, makes sense. Thanks. Already have a 4 set of bolt on spacers I wasn't using. was gonna mil them down to use for the front if this setup would work. But your reply makes sense.

 

Having a 235 on the front and a 315 on the rear in a car that is front heavy is going to make it understeer like a champ. You really need a 275 up front. There are a few 17" x 9.5" wheel that will fit with the QA1 CO conversion up front.

I'm going to disagree with Lonnie on the track width comment he made - in most cases (but not all), increasing track width can improve handling a bit. Keep in mind no matter the track width, the cornering force is sent through the tire into the hub where the wheel rotates (and that typically doesn't change position).

 

And I disagree with Paul, here. BUT everything is application specific.
It's hard to reply to the command/request, "Give me the best _____." What we need is a conversation.
Don't discount Paul's wheels, however. He did a nice job; light weight, no spacers, middle of the road style, good price point. They fit many people's application - quite possibly the majority demographic.
A car can only handle as good as the front end. Then you match the rear to the front's capabilities.
You're going to need new wheels with that set-up. If Paul's fit your coil-overs, then that's the cheapest/best way forward. Those 275's will work well for autocross, under 80 mph, and some street driving. This probably covers most people on this forum: xcross or small track driving events, never driven far from home, nothing constant above 100mph. The wider track width will hurt SAI and scrub - but for the above application, it will work. 275's won't be bad on the highway, it's just that the unsprung weight, SAI & scrub, will wear the tires more and work the suspension more . This will be more noticeable the more total elapsed time one spends above 80mph - I'm not talking occasional. Again, application is everything.
IF this car is a dedicated track car (no street), then 295's or even 305's and ditch the coil-overs. Who cares about scrub and wear them out having fun.
Higher speeds at long tracks, interstate driving, and more miles driven will be a different story. In my opinion, this application is better at 245; but everyone has an opinion and everyone has their own application.

 

TEDSgrad,

Figured you would chime in on this. lol

Everyone has a different approach to making the 3rd gens handle better - some like to lower the car into the dirt, others want coil overs, some others want maximum width tires. Some want a few or all of the above) Different strokes for different folks for the most part.

But as a street car guy, I think there are a few tradeoffs that one has to look into before pulling the trigger on putting something together.

I personally subscribe to a higher spring rate (not too high), lower the car about 1", excellent shocks & struts, aftermarket control arms, and a wide tire (275 or wider all around), plus weight reduction - unsprung and sprung. For a street car, this works best in 95% of the cases and even made our CMC racers more competitive (the wider tires anyway).

 

TEDSgrad, thanks for the support... you know where I am coming from.

Paul,
I generally agree with what you are stating above, but no where here does it say to unnecessarily space the wheels outward. I stand by my above statement of not running the wheels further outward than absolutely necessary for clearance, for the reasons mentioned above due to SAI, scrub etc.

Also as an FYI, a 275 tire will not cause any significant grief on the front end with the proper alignment. My car has seen many sets of 275's on the front for 6 years now & they wear evenly. I run it pretty hard & drive it everywhere. Only drawback I see is you need to slow down a bit in heavy rain as it hydroplanes easier.

 

Lonnie,

Just going off this statement you made above:

You DON'T need a wider stance as you are basically increasing leverage on the suspension, decreasing spring rate etc. This does nothing for handling & in fact unfavorably changes the suspension geometry.

Geometry aside, widening the track width can improve handling a bit - I had seen a test of some european cars (3 series and 996 I believe) that had used spacers to push the wheels out and they picked up some speed on the slalom. Obviously it wasn't 3mph, but it did register as an improvement. While those cars do have a more optimized suspension design, results would be similar in an F-body.

275s definitely hydroplane a bit easier than 245s.

 

Ditch the coil-overs and you can fit wider tires much more easily and effectively.
The thing about suspension is that there are always trade offs. A wider stance will reduce lateral load transfer which will produce more grip but you will have a greater scrub radius (not that big of a deal in racing), and you are also introducing a greater bending moment on the strut. You aren't really changing the geometry (I guess that depends on what you mean.. the roll center will go up slightly) but the handling balance may be adversely affected. I personally don't like the idea of increasing the length of the moment arm working to bend that strut, esp. the small shaft stuff like koni. If you want to know whether it will work, you can do this one of two ways, you can spend a few days working out the math (there is math for this), or you can just test it and see if you like it.

In case you were wondering, you can fit a 17x11 (with 315s) have a stock scrub radius, and drive it every day. You will need to put on your thinking cap and figure out how to make a part that allows this to work though. Otherwise, you can do it with +.5" on scrub. Another option is to go 18+"x11 on the wheel and just bolt it on with just some clearancing and have stock scrub radius.
P.S. Track width has nothing to do with SAI and contrary to popular belief, SAI isn't really a big deal anyway either way.