How much difference do 19's make?

[JspecB16]

When running the 1/4 mile in an E46 bmw 330 how much difference in time should it make running 19" rims over the factory 17's? I wasn't very pleased with my times on friday, although it was my first time running at the track ever.

[s3v3n]

... it should slow you down.
youll accelerate slower as you:
a) most likely have more unsprung weight now;
b) most of the weight if further from the center of the hub;
c) youve basically changed your gearing by having a larger distance to move per rotation.

if you werent pleased with your last track time, youll be even less pleased after adding 19s

[JspecB16]

^^^no, i had 19's on for both runs already. I'm wondering how much better my time will be with the factory 17's

[ogpog]

It depends if your total tire diameter differs by much between the two wheels. If you have lower profile tires on the 19's than the 17's, and your 19's arent that much heavier, you could very well make very similar track times as well with your 17's.

[Redlyne_mr2]

What sort of times did you run, you should be anywhere from mid 14s to low 15s

[JspecB16]

Originally posted by Redlyne_mr2
What sort of times did you run, you should be anywhere from mid 14s to low 15s

I know, but i didn't thats why I am wondering what the problem is. I didn't have the best launches, and i only ran twice. Someone later that night told me running 19" deep dish rims with hard rubber could be a second or even more added onto my time over runnning my winters on 17's. Is that accurate?

[JspecB16]

There are sooo many factors in running the 1/4 at the cars full potential, I just need to narrow it down to which of these factors are limiting me.

[rc2002]

The wheels won't make a huge difference. It's not like your times will get 0.5s better. Depending on gearing, if your tires are taller your times might actually go down because you might be able to finish the quarter mile at the top of 3rd or 4th.

[benyl]

Originally posted by s3v3n
... it should slow you down.
youll accelerate slower as you:
a) most likely have more unsprung weight now;
b) most of the weight if further from the center of the hub;
c) youve basically changed your gearing by having a larger distance to move per rotation.

Properly size 19s will not affect your gearing. This is misinformation.

Originally posted by ogpog
It depends if your total tire diameter differs by much between the two wheels. If you have lower profile tires on the 19's than the 17's, and your 19's arent that much heavier, you could very well make very similar track times as well with your 17's.

Simple answer is that your 19s are too heavy.

They could be 3 lbs light than your stock wheel, but your car still has to work harder to get them to start rotating because the weight is farther from the hub of the wheel. It is all about leverage.

[JspecB16]

I was just finishing off 3rd gear at the end of the 1/4. What other factors should i be looking into? I could improve my launching, but the shifting through the gears was smooth and fast.

[rc2002]

What's your 60ft time? That'll tell you if you need to improve launching.

Maybe you just need to buy a faster car. hehe.

[JspecB16]

a faster car?? The car is supposed to run 14.5 at sea level, stock. And i have a full cat-back exhaust too.

My 60ft was like 2.85 or something like that, I ripped up the time slips so i'm not sure haha

[benyl]

You biggest enemy is Calgary's altitude. What was the density altitude on the night you ran? NA cars suffer with altitude. Don't compare your times with people who live near the coast.

[JspecB16]

Im not sure what the density altitude was, but i hope i can have another chance to run before the end of the season.

Its weird cause a buddy of mine that has a 90 MR2 turbo, i'm neck and neck with all the time on the road, ran a 15.3 when he was bone stock at race city. He has since done a few little mods and we are still neck and neck when he's at stock boost. Maybe i should check my oil or something, there has to be something that threw me off so bad.

[QuasarCav]

Originally posted by JspecB16
Im not sure what the density altitude was, but i hope i can have another chance to run before the end of the season.

Its weird cause a buddy of mine that has a 90 MR2 turbo, i'm neck and neck with all the time on the road, ran a 15.3 when he was bone stock at race city. He has since done a few little mods and we are still neck and neck when he's at stock boost. Maybe i should check my oil or something, there has to be something that threw me off so bad.

The drag strip is the great equalizer. Street racing is a horrible way to compare because something like a .5sec difference can make your car appear alot faster.

I dont think the oil is the problem.

[JspecB16]

Are there any other suggestions as to what could be causing these shitty runs? other than practice haha

[JspecB16]

Somebody was telling me that Cwave ran a 14.7 at race city with his 01 330ci and all he had done was intake and exhaust.

[QuasarCav]

Originally posted by JspecB16
Somebody was telling me that Cwave ran a 14.7 at race city with his 01 330ci and all he had done was intake and exhaust.

Someone was telling me that Cwave might be a better driver.

[JspecB16]

Originally posted by QuasarCav



Someone was telling me that Cwave might be a better driver.

oh ok, thanks Quas

[Mr_ET]

Originally posted by JspecB16


oh ok, thanks Quas

Saw you running both runs here's a few tips

I have a 91 honda civic and last year ran it with 17's on overall bigger diameter. They also weighed about 3 pouunds each more then my stock 14's

ran a best of 17.3 with quite a few runs in the high 17 seconds. that was with my rear seat and jack and spare tire out.

this year i tried it with my stock wheels and winter rubber same everything else. I was 0.8 seconds faster.

Now I know my car has a much smaller engine with less power so it will be more affected by unsprung weight but it does make quite a difference.

your launched were also pretty bad bogged them both so it could have made your times about 0.3-0.6 something like that slower.

a rear drive car with decent power should hit 60 ft's of about 1.9 to 2.0 at race city so you are like 0.8 seconds off that.

i think your car on stock rims with a good launch is probably about a second and a half faster on the same night at the same track.

practice makes perfect!