How much does exhaust diameter matter

[nails]

I am about to go from a 60mm exhaust to a 70mm exhaust, but I am not remapping, at least not for the time being. Will the car be ok? I don't want any running issues, engine management lights, loss of power etc?

 

[kyle'87]

I am about to go from a 60mm exhaust to a 70mm exhaust, but I am not remapping, at least not for the time being. Will the car be ok? I don't want any running issues, engine management lights, loss of power etc?

I went from a 63mm to 73mm and didn't notice much difference, however my car is already fully mapped on the 63mm Exhaust, it isn't an OEM map.

I ran a log on Kpro the A/F is running a little bit leaner when booting it. Car is being mapped again soon.

If you are lowered consider you'll be closer to the ground with a different exhaust.

If you are completely OEM apart from a larger exhaust, i'd say you'll be OK.

 

[carl hammond]

I don't think you will really notice anything to be honest, have you got a KPRO or K100 etc already and if so who mapped it? if it was Romain he'd more than likely say you will be ok and to get a map when you do any other changes. I recently spoke to him about similar on mine and he said if I change anything then get the map once all the bits are on.

Mines not got an RBC as I think it's a lot of money for little gains and TGM advised the final drive would be a better modification to make over the rbc all day long.

What exhaust are you going from and too and is it just cat back or d.pipe etc also?

 

[nails]

No it is a standard map, as far as I know anyway. I haven't got a KPRO or K100 but probably will remap at some stage.

I am going from a JS Racing 60RS which is 60mm to a Skunk 2 Megapower R which is 70mm.

I am lowered on Bilstein B16's and I don't scrape currently, so hopefully that won't change.

I am more worried about the car not running right as it is not mapped for the exhaust.

 

[carl hammond]

No it is a standard map, as far as I know anyway. I haven't got a KPRO or K100 but probably will remap at some stage.

I am going from a JS Racing 60RS which is 60mm to a Skunk 2 Megapower R which is 70mm.

I am lowered on Bilstein B16's and I don't scrape currently, so hopefully that won't change.

I am more worried about the car not running right as it is not mapped for the exhaust.

If you are on a stock ECU it wont make any difference or if it does nothing noticeable mate, it's when its specifically mapped for mods and you change things you'd start to notice of see/feel a slight diff but a bolt on cat back wont really do anything diff so you will be fine.

 

[kyle'87]

Pretty much what Carl said, if you are on a standard map there is little you will notice.

 

[Grano]

I have the 70mm megapower on mine, with the alpha header. If you are lowered you will scrape, trust me. And be prepared to bend the rear hangers, you only have a few mm clearance between the rear sway and the frame. If you don't take the time to get it exactly right the rattle will do your head in :xaiweb4:

 

[nails]

I have the 70mm megapower on mine, with the alpha header. If you are lowered you will scrape, trust me. And be prepared to bend the rear hangers, you only have a few mm clearance between the rear sway and the frame. If you don't take the time to get it exactly right the rattle will do your head in :xaiweb4:

TGM are going to fit it so hopefully they will know what to do.

Do you like the sound of the exhaust?

 

[Grano]

TGM are going to fit it so hopefully they will know what to do.

Do you like the sound of the exhaust?

Yeah I do, it has a nice deep growl to it when floored, but near silent at 100kph cruise. Bit of a drone between 4000-4300rpm but I think I'm just deaf now, I don't really hear it. You probably won't like it straight away, Skunk2 exhausts/headers have a 'needles in a tin can' sound for the first few thousand miles. But once they carbon up a bit they sound great.

 

[Kenz]

I have the megapower r. The build quality is pretty poor, it knocks on the underside of the floor pan after you boot it. And the skunk2 badge on the back box has fallen off. But the sound is awesome! With a 421 it is loud and I think you'll struggle to pass any track limits.


Sent from my iPhone using Tapatalk

 

[SamDC5]

To be honest most of the flow characteristics are down to the exhaust manifold. Car may run a tad leaner down to air flow but won't really change anything as it's after the cat. You'll be fine I wouldn't lose any sleep over it.

Sent from my SM-G928F using Tapatalk