geddyup Posted October 18, 2005 Share Posted October 18, 2005 So I finally called the tire rack and ordered my new SSR GT7(18x8 with 225/40/18 tires) wheelset. I used a little less expensive tire called the firestone wide ovel with a W rating. I ordered Thursday and they arrived monday morning. Great turnaround. I have several questions. If the wheels are bigger does that mean it takes more time to bring them up to speed? If they are lighter then stock(they felt a ton lighter) wheels and tires will that compensate for my first questions. The car looks tougher then ever and I cannot wait for my new exhaust upgrades to really stomp on it. Thanks, Patrick Link to comment Share on other sites More sharing options...
rallispec Posted October 18, 2005 Share Posted October 18, 2005 In theory, any loss in acceleration should be offset in a gain in top speed. (plus lower cruising RPM’s on the highway, since you're basically changing your final drive ratio) However, the differences between an 18” and 17” wheel shouldn’t be to dramatic, Especially considering the 18 most likely has a lower profile tire. (and yes, those wheels should be a couple pounds lighter than stock) those are nice wheels, do you have pictures of them on your car yet? Link to comment Share on other sites More sharing options...
PGT Posted October 18, 2005 Share Posted October 18, 2005 225/40/18 is taller than than the stock 215/45/17 size by about half an inch. That means your car will sit 1/4" higher off the ground. Did you weigh the combo before mounting? Link to comment Share on other sites More sharing options...
PGT Posted October 18, 2005 Share Posted October 18, 2005 moved to 'wheels/tires' Link to comment Share on other sites More sharing options...
geddyup Posted October 18, 2005 Author Share Posted October 18, 2005 I need to get some oictures of the car. Just waiting to get offf my mountain bike to do it. The weight difference with tirs was almost 10lbs per wheel. Link to comment Share on other sites More sharing options...
AreEyeSeeKay Posted October 18, 2005 Share Posted October 18, 2005 If the wheels are bigger does that mean it takes more time to bring them up to speed? It Depends. Roational Inertia is proportional directly proportional to Mass but proportional to the square of the radius ( I = m *r * r). In order to figure out the improvement theoretically you would need to have a cross section showing how the mass was distributed in the old tire/wheel combination and the new tire wheel combination. (and someone who remembers Calc 3&4). Link to comment Share on other sites More sharing options...
PGT Posted October 18, 2005 Share Posted October 18, 2005 The weight difference with tirs was almost 10lbs per wheel. I just looked at the specs. Wheels are 17.2 and tires are 24, so call it 41 lbs and change. The stock wheels and tires are about 43-44lbs, so you are actually about 3lbs lighter per corner. Not alot, but enough to offset the higher gearing of the larger tire size. Link to comment Share on other sites More sharing options...
AreEyeSeeKay Posted October 18, 2005 Share Posted October 18, 2005 There are two effects here, the effect of the increase in radius on gearing, and the effect on the change in rotational inertia as a load on the engine. If P Gt's numbers are right then I wouldn't expect any increase in accleration. Link to comment Share on other sites More sharing options...
PGT Posted October 18, 2005 Share Posted October 18, 2005 My Volk's were 40.5 per corner with 225/40/18 tires and I felt NO difference at all. Link to comment Share on other sites More sharing options...
sandwood Posted October 18, 2005 Share Posted October 18, 2005 why someone will pony up big $$$ for rims and then cheap out on tires I will never understand. those are sweet rims though. enjoy. getting out of the legacy game Link to comment Share on other sites More sharing options...
geddyup Posted October 18, 2005 Author Share Posted October 18, 2005 The tires are almost the same as the bridgestone just for less cost. The reviews have been good and consistant as well. With the way I drive I should be changing them next year anyways 12 bikes(where the wheels and tires cost more then my car) and one fast car Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.