2006+ Honda Civic Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
2,417 Posts
Discussion Starter #1
this should be in the tyres section, but is not because i want to talk about power.

let's talk about tyre diameter and weight.

As you know our car comes with 225-40-18 tyres - R050 potenza.

This tyres have 25.1" of diameter and 25 lbs of weight. This tyres will make 830 revs per mile.

Let's see other tyres like 225-45-17 - RO50 potenza also

This tyres have have 25" of diameter and 24 lbs of weight. This tyres will make 833 revs per mile.

almost the same.

But let's see other tyres, like the 215-40-17 - advan neova AD08

This tyres have have 23,7" of diameter and 21 lbs of weight. This tyres will make 875 revs per mile.

You gain about 4 lbs on every tyres and about 10lbs on smaller wheels than stock. That is a huge gain!

More, the smaller diameter tyres will give you a much faster acelaration because you efectively lowering the gear ratio hence increasing acceleration but reducing top end speed.

And lowering the gearing to the ground would be equivalent to increasig torque to the ground.

changing 225-40-18 to 215-40-17 will make the car much much faster on accelaration.

If there is any problem with the speedo, you can adjust it with flashpro.

Good or bad power mod?
 

·
Registered
Joined
·
120 Posts
Reducing unsprung rotational mass by fitting lighter wheels will improve acceleration , braking and handling. I switch between the stock wheels (12,7 kg) for winter and OZ Ultraleggera's (8 kg) for summer and you can definitely feel that the car is more responsive on the lighter wheels. Both sets are 225/40 18's .
Using 215/40 17's will give huge gains in weight and improve acceleration by the lower gearing but could cause more torque steer problems perhaps (on a car with the open diff).
To avoid losing lateral grip I would keep the width at 225 or perhaps even go for 235/40 17's ? The circumference of the 215's is 5,24% smaller than stock , the 235's are 2,73% smaller . So these would still improve acceleration by reducing the gearing and improve overall grip. On light racing wheels the 235/40 17's will still give significant gains in weight as well.
 

·
Registered
Joined
·
2,417 Posts
Discussion Starter #5
very true. I only put the 215-40-17 as the difference is very big. You gain about 5% of accelaration and less weight. The 215-45-17 is another option.
 

·
Registered
Joined
·
2,417 Posts
Discussion Starter #6
so if i put 15"s on ill be faster than a Focus RS?
don't know if this a joke or not, but all race EP3 civic type R in portugal had 16" wheels.
 

·
Premium Member
Joined
·
6,644 Posts
this should be in the tyres section, but is not because i want to talk about power.

let's talk about tyre diameter and weight.

As you know our car comes with 225-40-18 tyres - R050 potenza.

This tyres have 25.1" of diameter and 25 lbs of weight. This tyres will make 830 revs per mile.

Let's see other tyres like 225-45-17 - RO50 potenza also

This tyres have have 25" of diameter and 24 lbs of weight. This tyres will make 833 revs per mile.

almost the same.

But let's see other tyres, like the 215-40-17 - advan neova AD08

This tyres have have 23,7" of diameter and 21 lbs of weight. This tyres will make 875 revs per mile.

You gain about 4 lbs on every tyres and about 10lbs on smaller wheels than stock. That is a huge gain!

More, the smaller diameter tyres will give you a much faster acelaration because you efectively lowering the gear ratio hence increasing acceleration but reducing top end speed.

And lowering the gearing to the ground would be equivalent to increasig torque to the ground.

changing 225-40-18 to 215-40-17 will make the car much much faster on accelaration.

If there is any problem with the speedo, you can adjust it with flashpro.

Good or bad power mod?
Put the numbers in here nuno, it will work out how much your need to correct the speedo via flashpro:

Tyre Calculator - Alloy Wheels - Specialist supplier of alloy wheels and tyres packages, Fast Delivery, Buy Online.
 
  • Like
Reactions: nunoctr

·
Registered
Joined
·
2,417 Posts
Discussion Starter #8

·
Premium Member
Joined
·
50 Posts
Excellent post ..... so if rolling radius 5% smaller and therefore gearing reduced is equivalent to a 10hp power increase!! Love it .... if you haven’t got 15’s on your CTR you just not committed enough ... !!
 

·
Premium Member
Joined
·
6,644 Posts
215-40-17 will give you smaller circumference so better performance as I understand it, I'd go with them
 

·
Premium Member
Joined
·
390 Posts
If we're talking purely straight line acceleration, I use 16*8 as a circuit rim on 225/45/16 which a pretty low profile for a 16" tire. The acceleration difference to the stock 225/40/18 is massive. Provided the tires you are using can put power to the ground, it is a much easier mod to shorten gearing than changing final drive, I needed to correct the speedo on the flashpro by significant margin.

If I had to compare it to a "power" mod I'd say its a bigger gain than the delete kit or lightened flywheel combined! For small penalty of it looking like crap, it's definitely worth it.

Also, when you're looking down to the tiny details, don't take tire size as gospel, I've stacked same size tires side by side before and found them to have different width, not so much difference in rolling diameter though.
 

·
Registered
Joined
·
2,417 Posts
Discussion Starter #13 (Edited)
thanks for the advice.
I had a ep3 and run against some ep3 with the fn2, and i think the biggest advantage of the "old" car is the tyres/rims on accelaration.
I am going to run 17-7,5-38ET (probably 215-40-17) so i don't think it will look very bad.
advans AD08 215-40 probably are better putting power down than the 18" R050 225-40.
 

·
Registered
Joined
·
2,417 Posts
Discussion Starter #15
yes but ebay have great deals and tyres are cheaper.
 

·
Premium Member
Joined
·
2,937 Posts
I would love a set of 17"s, bur cant afford them at the moment.

If i did have them, i would go for 235/40 17 up front and 215/45 17 at the rear.

Its a "second" set so, when you want to go for a track day or go for a couple os fast drive on bendy roads use the 235's up front,...... if you fancy a couple of "test" like 60 km/h roll (you know what i mean Nuno) use the 215's up front....

That would be what i would pick. ;)
 

·
Registered
Joined
·
2,417 Posts
Discussion Starter #17
thanks paulo

this will be my race wheels"

My every day wheels are and will be my advan racing 18".
 

·
Premium Member
Joined
·
2,937 Posts
thanks paulo

this will be my race wheels"

My every day wheels are and will be my advan racing 18".

My point exactly.... !!!

235/40 17
215/45 17

Neovas or the new Azenis....

Gives you both...
-Traction if you want if (235's at front)
-Straight line accelaration (215's at front)

Would love to have the chance to do this myself.

Forca com isso!!
 

·
Registered
Joined
·
6 Posts
I've fitted my FN2 (just for fun and to ssee how it drove) with some 17" Rota Circuit 10 running 225/40/17 if i'm not mistaken, and the car felt much faster on accelaration...i really liked the feeling!!

I went to a Honda dealership to see if I could fit some 17" and they said it couldn't be approved so i ordered some 18" instead...funny that we have 16", 18" and 19" approved by Honda not 17"...
 
1 - 20 of 27 Posts
Top