Hi forums members, often when people buy vehicles motorcycles and cars they often think they improve performance by purchasing add-ons, ie. wider tires, exhaust systems etc. I got my undergraduate degree in Mechanical Engineering ( at one time I wanted to design cars, I didn't long story) so... I think I have a little knowledge in this area. Alot goes into the design of a car. When tires are changed (ie. 17s to wider 18s) it effects the overall gear ratio, fuel economy, different exhaust systems need richer or leaner mixtures of gas (which is probably compensated by the EFI.

Of course it up the owner to do as he pleases but do we really know better than the people who spent years learning how to design these cars. What prompted this post was a statement from another post saying that the rear tires of a G35 were too narrow for a car with 260 hp. I am sure the engineers spent plenty of time thinking about this.. Often we consumers think we know better through spicy advertisements which influence us to buy after market products claiming significant improvements in certain areas.
Maybe its true, but I say "caveat emptor"!

Personally, I will leave my car stock and leave the changes for the true professionals and experts. Oh yeah I used to do alot of modifcations with motorcyles and cars that I have owned but I found when i left it stock MUCH less problems and easier to resolve.

Well this is just my 2 cents. It is something to think about.

Dknibb " The Emerald one"

<P ID="edit"><FONT class="small"><EM>Edited by DKnibb on 04/02/03 07:16 AM.</EM></FONT></P>

 

For the most part, I agree with you. I think people don't take into account all the factors when they make modifications to their cars. However, while the engineers that design our cars know much more than we do, they have design goals to meet that may not align with our personal choices. They have to meet certain emissions and economy guidelines, they have limits to the amount of noise the car can generate, etc. Plus, they try to squeeze it into a package with a certain price point so that it can be marketed effectively. So, there is some room for improvement.

Of course, my car will be staying in stock form for quite some time, except perhaps when the current tires wear out, I might go with 235/50R17's -- not because they're wider, but because they're the same diameter and there are many more tire choices available than the meager offerings in the stock 215/55R17 size.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

You're sounding like you're in the same age bracket as me.[img]/w3timages/icons/smile.gif[/img]. There was a time that I knew better than the manufacturer tho. We've all been there. [img]/w3timages/icons/laugh.gif[/img]

<font color=red>GSM</font color=red>

 

NO ONE is in the same age bracket as you.[img]/w3timages/icons/laugh.gif[/img]
There are gives and takes in everything, including the manufacturing process, so you are all correct.
It comes down to that when you Mod a car there are always other things to consider. Ying and Yang I guess.

<font color=blue>Merlin</font color=blue>

 

Do your comments apply to simple upgrades like CAI or exhaust systems? Do these modifications require that the computer/engine be re-tuned? I see the manufacturers boast performance improvements - how are they achieving these improvements if what you say is true?

I'm not trying to be confrontational - it's just that I've been considering getting a CAI and want to make sure I'm not doing more damage than good...

 

A wider tire was just a suggestion and would be the easiest and cheapest change I can think of to help cure the G's tendency to oversteer. Obviously, there a multitude of factors (center of gravity/roll center, spring rate, etc) that will affect how a vehicle handles.

 

townsley, this is what a forum is all about. I thrive on discussions and alternate opinions.

I just think one should think and research first and not always expect significant improvements. Go for what you want, I would go a step further and call the manufacturer and ask specific questions about proper installation . That cannot be taken for granted.

As for Merlin, Damn how old is old man! I'm 43 and I feel like a spring chicken! Attitude is altitude dawg!!

Same age bracket, how old are you Merlin?

Dknibb "The Emerald One"

 

Hey Gsedanman, Merlin is hittin hard! :O

Few can understand and appreciate our diverse experience and knowledge! We elderstatesman know and these young whippersnappers are beginning to find out!

Gotcha Merlin!! LOL

Dknibb "THE Emerald One"

 

texasG35, you are obviously a man who knows what he is talking about. Well said and I agree.

Also wide tires look so cool...

 

Actually dude, he's chirpin' pretty hard for someone that's not that far behind............[img]/w3timages/icons/smile.gif[/img]

<font color=red>GSM</font color=red>

 

I would have to agree to both sides, but then you do have to consider all the factors and limitations a manufacture has to go through. Why do they put 15" rims with dinky tires on a Civic Si/SiR? They save money this way and Honda knows that anyone who buys this car will modify it no matter what you tell them. Everything said above is true in their own way i guess...except for the 'old' remark towards gsedanman. I got ur back man!! [img]/w3timages/icons/smile.gif[/img]


It's still a G thang!!

 

Not sure if this was directed at me but changing to a CAI will give you more performance, downside, you will want to use it.[img]/w3timages/icons/smile.gif[/img] As for the exhaust, I like a good sounding one just like the other guy, but again when you use that extra added performance the Smoky can hear you coming.[img]/w3timages/icons/smile.gif[/img]

BTW, GSM who said I was not far behind you?[img]/w3timages/icons/laugh.gif[/img]

<font color=blue>Merlin</font color=blue>

 

I agree in principal with the first post, but that doesn't mean that some intelligent choices can't be made. You have to remember that the original equipment is based on what will appeal to the most people in the targeted market. There are always going to be people who have certain ideas of what could be improved. The important thing to remember when considering modifications is that everything is a compromise. Whatever benefits you get by making a change, be it real or imagined, is offset by giving up something else.

I have made a lot of modifications on another car that I own, and most of them have been beneficial. However, they have changed the basic personality of the car, which, in this case, is something I was trying to do. On the down side, I now have many more squeaks and rattles than I would have if the car was still stock.

As for the G, I think it needs a few refinements, but not many. I would like to lower it just a little, as there is just a bit too much body roll for me. I would also like to get wider tires. If and when I do this, I will make sure to keep the overall diameter of the tires as close to stock as possible. As long as this is done, it won't effect the speedo, the gear ratios, or ABS. At some point, I will look into freeing up the intake and exhaust, and possibly getting a supercharger or turbo. Since the G is the car that my wife uses most of the time, I may have to wait on those for awhile, though! Oh, and I'm 47, by the way.