LOL! That's my friend's car. I hate him. Just his wheel is showing and it's enough to make my car invisible.

 

ordered the nitto invo 225/45/19

 

Very good point, the formula is not quite complete. You have to remember that the width is in mm and the wheel size is in inches, so you have to do some metric to SAE conversions to use this method. So basically a 225/50R18 would be 225 mm x .50 / 25.4 (25.4mm / inch) = 4.37" (this is your sidewall height in inches) x 2 (your tire has sidewalls on either side of the diameter) + 18" (this is your wheel size) = 26.74" (this is your total outside diameter of your tires). A 245/40R19 would be 245 x .40 / 25.4 = 3.86" x 2 + 19" = 26.72". Since 26.74" ~ 26.72" then this tire size would be a great match for your orignal tire size. Now this is only an estimate of the actual rotating diameter, and not an actual diameter.... because each tire design is slightly different, some tires may actually have a slightly flatter contact patch and some may be slightly coned in the middle, so this can also effect the actual rolling diameter of a tire.. so, it's always best to look at the actual diameter given by each tire manufacturer for a particular tire in a given size, however, it's not rocket science, so the calculation method will get you very close. Any way you look at it, if you increase your wheel size by one inch, then you are going to have to decrease your sidewall height by 1/2" (1" / 2) in order to keep the same overall diameter. So, your best off to choose a tire without a stiff sidewall if you want to still maintain a composed ride.. ride quality actually has more to do with the tire design (sidewall stiffness in particular) rather than sidewall height or aspect ratio... that's one reason that most run-flats have such a harsh ride.

I also would like to strongly discourage you from using a tire that has a vastly different outside diameter than your stock tires... doing so would effectively change the final gearing of the car, as well as throw the speedometer & odometer off, and can also effect the ABS system. This becomes very apparent when you put oversized tires (that are like 2 or 3 or more inches larger than stock on a truck, but can also be noticeable with smaller changes. If you are within a 1/4" - 1/2" of your stock diameter, then you should be fine, as the overall diameter of a tire can change this much over it's life just from tire wear alone.

Let me know if you need any other help with tire sizing, etc... I sold tires for Michelin in a previous life, so I've been through all of this before.

 

FYI... These would be 225 x .45 / 25.4 = 3.99 x 2 = 26.97" overall diamter. So these are within a 1/4" of the orignal tire size, so they should be fine, although the 245/40R19's would be ideal.

 

This is simply a gorgeous picture, AesonVirus... Beautiful car you got there... and the GT-R isn't too bad either.

Now you just need some Impul's or Eibach's and you'll be all set. I'm still trying to decide which springs to go with on my car.

 

I dont think he understands that the 2 sizes have the EXACT same outer diameter even though one is a 45 series and the other is a 40 series.

 

Thanks dude... My car was one of the first at a local meet last fall and some guy walked by and snapped that pic. I then found it posted on a Mazda forum of all places. That meet ended up being one of the best anyone can remember in recent years. Awesome time!

I'm totally sold on the Impuls. I have been since Ddubb did his G last year. I'm still working on securing the cash for the Springs and I'm also shopping around for a local shop to do the install.

It's only a matter of time!

The GT-R belongs to a friend of mine. In these pics, his car was something like 5 months old and he was still on the same tank of gas. Later in the evening, another GT-R pulled in and he had something like 60K on his already.. it was his daily driver... winter and all!
Must be nice.

 

Yup, exactly my point... one is a 45 series 19" and one is a 40 series 19", but they both have basically the same sidwall height and overall diameter, so the ride will ultimately be decided based on the tire design, not the size.

I probably should have been as concise as you, but then again, I like to talk a lot. LOL

 

if i would have purchased the 19x8.5s, I would have gone 245/40/19. I went with 19x8s all the way around. Based on nitto's invo website, the 225 seems a little better for an 8in wide, than a 245.

 

Either way, I'm sure you will be happy. I actually have 225's on 8.5" wide wheels on the front of my Porsche, so the 225's will probably be perfect on your 8" wide wheels.

 

That's a great story behind your pic.... I wish I could find an awesome pic like that of my car floating around the web. LOL

Can I ask you what made you choose the Impul's over the Eibach's. I'm just not sure I can justify the price difference for the Impuls... although, I'm trying very hard too. Also, why not install the springs yourself? It's actually a VERY easy install, especially if you have a spring compressor tool.

Oh, and tell your buddy, I love his GT-R... That's probably my next car... just like his... an ivory pearl GT-R!

Sorry, Bat, I didn't mean to hijack your thread....

 

Even at stock height, I'm touching frozen crap in the middle of the road during the winter months. My drop has to be subtle to rid me of unnecessary wheel gap but the car needs to remain practical as my daily driver.
I also like the idea of it being a minor drop, which will save a little extra life in the shocks as well.

Installing them myself... I considered it until I read some horror stories about the front shafts popping out in the X. They're a nightmare to get back in. I have two little ones at home and the wife always books my weekends solid. Any project I take on has to be small. I'll have 2 hours allowanced to me (tops) if I decide to do these myself.
It's easier to hit a shop and drop $150.

Besides, I love watching other people work.

 

2GoRNot2G - Get the Eibachs. You live in SoCal. No need to worry about clearance for snow. The Eibach drop looks better and the springs are 1/2 the price of the Impuls. I've been running Eibachs for a while and the ride is fine. The car doesn't bottom out on the bumpstops, handling is good, and it feels like virtually no compromise. IMO, the drop w/ the Impuls is too subtle.

AesonVirus - I hear what you're saying about doing work yourself. I used to do all my own suspension work. Just before I got my G35, I unlowered my TSX when I was trading it in. After I was done, I felt all beat up and sore, not to mention I had to take time off during a workday so the kids wouldn't be coming by asking me a million questions, etc. After that I decided my days of wrenching on the car (w/ the exception of super easy stuff like oil changes) was done. So, I paid $150 to have someone lower and align my G35.

 

Hehe... I know what you mean, but I never trust anyone else to do it right, so I always do the work myself. I'm in the same boat as you and have 2 separate companies that I run, so my time is very slim, but I can usually find a couple of hours to work on my car...You should be able to knock the springs off in an hour and a half, two tops. I wouldn't worry about the front half-shafts poppoing out of the spline, just be careful when you are doing it and maybe even use a coat hanger to keep the front spindle from dropping too low when you have the shock removed.

Of course, if you don't have the time or don't feel comfortable doing the work, then by all means have it done by a Pro... It never hurts to pay to have something done for you, if it means its gonna be done right.

Good luck and let me know how you like the Impuls!

Hey man... Thanks so much for the nice review on the Eibachs. That sounds like exactly what I'm looking for. I was just affraid that they would be too stiff. I don't think I can justify the price difference for the Impuls.. they will end up costing me over $400 more than the Eibachs even if I do have to buy a rear camber kit, that will only run me $150 - $200, so I'm still quite a bit cheaper with the Eibachs.

 

If you want pics of what your ride is EXACTLY going to look like, you know where to look ....well minus the rims.
But, yes, I would recommend the Pro-kit (unless you are going to go bananas like kulg35 and install electronic adjustable coilovers...bastard. I kid, kid. but i'm green with envy)