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View Full Version : why not 345's in the rear



70ptta
02-17-2005, 11:18 AM
Hey why does everyone go 335's and not 345's like on vipers? I know they come with 345/30/19 in the rear. Is it to much work for just a little more. Does anyone know if 345's will fit in the des mini tub kit.

F70t/a
02-17-2005, 11:59 AM
Jeff Andre is doing 345/30/19's and its not much more work then doing 335's. I think it comes down to money. 19's and 345's cost more then 18's and 335's. It also helps if your trying to fit a 345 on a 2nd gen :git:

F70t/a
02-17-2005, 02:57 PM
Jeff Andre is doing 345's in the back. it shows what he did. hope this helps you out some :bananna2:

http://pg.photos.yahoo.com/ph/[email protected]/my_photos

70ptta
02-17-2005, 03:11 PM
what do you mean it helps if its a2nd gen? Is it easier than a first gen and what do you think the 18's will out perform the 19's.

Ralph LoGrasso
02-17-2005, 03:12 PM
Most people stick with 335s, or even 315s so that they have a good balance between front and rear tire sizes. The vipers that run 345s, also run 275s up front. Most people go with the standard 245 on the front of their first gens, although a 275 can be made to fit. 345s will not fit in the DSE mini-tub kit on a 67/68, but I think you can make them fit on a '69. An 18" wheel will generally lend itself to slightly better handling than a 19" wheel, as well.

Steve1968LS2
02-17-2005, 04:55 PM
To me if the differential in size between the front and rear tires (width) is too great then your performance will suffer.. with a 245 front tire anything wider than a 315 in back would seem to be more for form than for function..

MuscleRodz
02-17-2005, 11:33 PM
Besides more money, there is a lot fewer choices for 19" wheels. Plus you are going from a 26"ish tall tire to near 28" tall which makes a harder fit on a lot of cars.

Mike

jeffandre
02-18-2005, 10:17 AM
In looking for a way to fit wide tires up front I realized I needed 18+" wheels (the 17x9.5's were hitting the UBJ and coming too close to the UCA's as well. That said, I calculated that a 19" rim minimum would clear everything fine, so I started looking at my options, which were few in 2002.

I ran across a pair of Michelin Pilot Sports 345/30/19 brand new for $300 total (I think that included shipping too!), so I went ahead with the setup on the rear on a 19x13 wheel from CCW. I used a standard width rearend, had the backspace setup to somewhere in the neighborhood of 9.825", and pretty much reengineered the rear suspension to make everything fit and work. I will be running 19x11's up front, with 295/35/19's, so the rear tire diameter will be 27.4" and the front will be 27", so there will be some sidewall going on.

I do not expect to have the greatest handling car out there, just a badass looking car that will always handle better than my abilities. Of course a person with the driving abilities of a Jeff Schwartz would undoubtedly find the weaknesses fast and lead to corrections as practical, I doubt I will because it will take years to get there for me. I am building some adjustability into the suspension in order to become better at fine-tuning everything for my style. I will also be adjusting the UCA positioning as needed to capture the needed camber and caster position range I want (based on plenty of proven research done by others).

The 2nd Gen has a wider body as far as I know, allowing more tire room overall, and the Firebird has the better fender flares, so they may end up on my car someday...

yody
02-18-2005, 11:17 AM
have fun with 11's up front! can you say 9 point turn!!! Have you actually even tried mocking anything up? By the looks of things it seems anything bigger than a 9.5" up front would hinder turning big time. WIll it clear the inner fenders?

F70t/a
02-18-2005, 11:29 AM
The frame I gave jeff i mocked up a 17x11 rim up front. With a custom sway bar and notching the frame it can be done. also the stock upper and lower control arms will need to be notched depending on BS.Fitting a huge rim upfront would be easy if you use after market parts and not stock. The tire stuck out a 1/4 passed the fender( this was with a 17x11).I dont really remember the bs since this was done almost 2 years ago.I give props to jeff for being different on the tire combo. I will be running a 18x12 up front and a 19x14 in the rear.:ssst: I will be making my own frame which will make my life easier

baz67
02-18-2005, 11:44 AM
Remember you do not get that extra width for free. If you do nothing to change the front geometry or backspacing there will be an increase in scrub radius and that is not a good thing. You will also have to help out the power steering out or you will burn that up as well. I am not saying what is being done is bad as long as you are willing to live with the sacrafices to do it.

Brian

F70t/a
02-18-2005, 11:47 AM
I was palnning on changing the geometry and not using any stock suspension parts, just the frame. At the time i had my stock front end on and i wanted to see if it could be done. thats why i did some mods up front to see what i would need to make it happen. :hmm: again it's alot of work and planning to make it right. thats why i'm building from scratch

yody
02-18-2005, 11:54 AM
....call me then so i can see when the car is done with the frame :enguard: why go through all that trouble for an extra inch of rim. Why not just go with a 10" wheel? with 19" tires you pretty much either go with 295/30/19 or 345/30/19 and a 295 fits perfect on a 10" wheel(ask me how I know) So if you go with a 19x11 all you will be doing is stretching out the tire more. This is all for michelin pilots, Pirelli makes a 305, but i am assuming jeff wants matching tires front to back. Agreeded it would be pretty cool to have a 11" wheel up front to match the 13" in the back. Also with the frame did you mock up the inner fenders? I imagine the engine bay would get pretty dirty without them. Also on making a custom frame, are you making one just for tire clearance? because i don' tthink the frame gets in teh way very much on a second gen. It would be cool if done, but there just seems to be way more cons then pros

MuscleRodz
02-18-2005, 12:21 PM
Jeff, where did you find the 345's for $300? I have not been able to find them that cheap. Which CCW wheel did you go with. I have been looking at the 505's.

Mike

F70t/a
02-18-2005, 12:24 PM
I decided to ditch the front frame when i found alot of rust on my rear rails. I will be doing a full frame. I did not mock up the stock inner wheel wells. No way would they fit witout alot of work. so when the time comes i will be making my own(something like the banks camaro)

70ptta
02-18-2005, 02:19 PM
so far its looking like 335's on a 18*12 rim and 245's on a 9-9.5 rim out front hopefully with a wayne due c5 frame, and maybe the martz rear but im still trying to figure things out

Steve1968LS2
02-18-2005, 04:54 PM
Remember you do not get that extra width for free. If you do nothing to change the front geometry or backspacing there will be an increase in scrub radius and that is not a good thing. You will also have to help out the power steering out or you will burn that up as well. I am not saying what is being done is bad as long as you are willing to live with the sacrafices to do it.

Brian

Look for the Scrub Radius story in an upcomming (june) issuer of PHR..

Mucho SR is a bad thing...

jeffandre
02-19-2005, 12:06 AM
I may end up with 19x10's, but would use 275/35/19's (26.6" diameter) for the same fit as the 345's on 19x13's (27.4" diameter). I have aftermarket control arms, and from my previous mockup experience the arms did not get in the way of the 17's, so the 19's would be even better. The upper ball joint and steering knuckle were an issue with 17's, again I believe the 19's will help here as well.

The inner wheel wells will be custom-made to fit everything, I do not need 275-295mm wide tires throwing crap into the engine compartment, enough gets in there from the stock wells and the previous 275/40/17's on 9.5" Vette wheels.

I got my tires from Bones.com, hard to find them anymore. My CCW's are the SP16A's. When I get the front wheels (after my bonus check next month, woohoo!) I may get tires from CCW installed as well if I cannot get them way cheaper somewhere else. Getting the 345's installed was a chore, had to take a damaged wheel to a shop for repairs.

I will make suspension adjustments as necessary to maximize the fat front tires, like relatively level lower control arms at ride height, optimum camber and caster ranges as practical (maybe taller ball joints, some form of the Guldstrand mod, new spindles). This will be a low speed car for tighter tracks and street fun (within safe limits).

jeffandre
02-19-2005, 12:10 AM
It is important to remember (for myself as well) that I have such a long wait to get the money for body and paint (2+ years away) that I might as well keep tweaking on the tire/wwheel combo, brakes, and suspension. Things would be way different if I was trying to get the car road-worthy this year, but that is not the case. So for now I tweak and learn. I have a month before my bonus money allows me to get the front wheels and tires, so I will begin removing the front end sheetmetal in a few weeks for wheel fitment.

wickedmotorhead
02-19-2005, 01:27 AM
Sweet I also will be going the big tire route 315 18s up front and 345 19s out back. Fitting them without a lot of work is an understatement haha.