Supercharged EP3 - Noise levels

[Lewr1407]

Hi all,

Just looking to get some advice please - I run a fully stripped out track setup rotrex supercharged EP3. I have a Gruppe M intake and a Solid Fabrications 3” super silent exhaust system installed.

During some track days last year, I was pulled up for noise exceeding limits (understandably!). In order to reduce noise from the car, do you think the fitting of a Fujitsubo 2.5” system would reduce noise levels appreciably without sacrificing too much power? I’ve had experience with the RM01a on previous cars and they were great.
Also, there will be some induction noise associated with the Gruppe M so that could be changed to reduce noise levels too.

Appreciate that I may lose power running a 2.5” system and may need to be remapped.

Any thoughts or advice would be greatly appreciated.

Thank you in advance guys!

 

[Chris.]

It’s most likely the intake noise that’s flagging you, the Gruppe M is offensively loud.

 

[Lewr1407]

Hi Chris,

Many thanks for the knowledge and advice - greatly appreciated.

All the best,

Lewys.

 

[Chris.]

I ran a GM on my NA DC5 and got black flagged at Brands. I switched it over to a Mugen I had with me and no more issues.

 

[Lewr1407]

I ran a GM on my NA DC5 and got black flagged at Brands. I switched it over to a Mugen I had with me and no more issues.

Hi Chris, I’m looking at getting the Mugen airbox to pair with my supercharger to keep induction noise well in check. I would imagine I would lose a bit of power coming from the Gruppe M, but do you think the Mugen would be suitable for the EP3? I’m fed up of always getting black flagged and tempted to part with the car if I’m honest. The other option would be to get an Injen/AEM CAI, but again, it’s open coned and may not reduce drive-by noise that much, even though enclosed within the wheel-arch. Any thoughts or experience at all?

 

[Chris.]

The Mugen will work fine but it is considered restrictive in FI applications.

 

[Carl Hammond]

Hi all,

Just looking to get some advice please - I run a fully stripped out track setup rotrex supercharged EP3. I have a Gruppe M intake and a Solid Fabrications 3” super silent exhaust system installed.

During some track days last year, I was pulled up for noise exceeding limits (understandably!). In order to reduce noise from the car, do you think the fitting of a Fujitsubo 2.5” system would reduce noise levels appreciably without sacrificing too much power? I’ve had experience with the RM01a on previous cars and they were great.
Also, there will be some induction noise associated with the Gruppe M so that could be changed to reduce noise levels too.

Appreciate that I may lose power running a 2.5” system and may need to be remapped.

Any thoughts or advice would be greatly appreciated.

Thank you in advance guys!

The power drop from a SF 3" to an RM01A 2.5" will not be noticeable. When investigating systems for my DC5 the best system was the RM01A when considering all the below:

Weight
Power Gains
Quality
Fitment
DB Levels (static and driveby)

The RM01A weighed less than half the SF 3" so the loss in power (a few hp that you'd never notice) was gained in weight reduction

If you chase numbers or feel the need to get every HP from the car (whether you'd notice them or not) then keep the SF, else imo I would swap it out for a better sounding, fitting and lower DB exhaust of which the RM01A was the best when I looked and I considered every system I could find both UK and Japan based for the car.

Intake noise will be the worst thing, I ran an AEM long arm down in the bumper, with a DC Sport Header (built in decat) and the RM01A and the max DB I ever got was 89db on driveby as my mate worked there and was monitoring it for me.

As Chris has said Mugen will greatly reduce the Gruppe M Intake noise also.

 

[Lewr1407]

Hello Gents,

I know the exhaust and intake choices have been asked a thousand times in general before, but I really appreciate your time taken to offer some advice, thank you. I’ve struggled to find experience with regard to reducing supercharger db levels and black flags, so my thanks again.
The car absolutely flies as is so I’m not interested in chasing power; being able to use the car alone outweighs all of that.
For 2022, I think I’ll try an Injen CAI and a Fujitsubo RM-01a and see how we get on. I’m tempted to purchase a second hand Mugen kit available locally, but the restriction may not be worth it over the CAI, assuming that the CAI will reduce the intake noise by a few db over the Gruppe M.

Thanks Gents and let me know if you have any other thoughts,

Lewys

 

[Carl Hammond]

Hello Gents,

I know the exhaust and intake choices have been asked a thousand times in general before, but I really appreciate your time taken to offer some advice, thank you. I’ve struggled to find experience with regard to reducing supercharger db levels and black flags, so my thanks again.
The car absolutely flies as is so I’m not interested in chasing power; being able to use the car alone outweighs all of that.
For 2022, I think I’ll try an Injen CAI and a Fujitsubo RM-01a and see how we get on. I’m tempted to purchase a second hand Mugen kit available locally, but the restriction may not be worth it over the CAI, assuming that the CAI will reduce the intake noise by a few db over the Gruppe M.

Thanks Gents and let me know if you have any other thoughts,

Lewys

Mugen will be far quieter than the Injen or AEM long arm CAI (I bought a Mugen intake for mine for that very test), but when the DC Sport baffles went in the back box I just bought the RM01A and never had an issue again so kept the mugen until I had done some of the Brands evenings (where they are really strict) and sold it after never having even been close to the db limit

 

[Lewr1407]

Mugen will be far quieter than the Injen or AEM long arm CAI (I bought a Mugen intake for mine for that very test), but when the DC Sport baffles went in the back box I just bought the RM01A and never had an issue again so kept the mugen until I had done some of the Brands evenings (where they are really strict) and sold it after never having even been close to the db limit

Hi Carl, perfect, thanks for that, good to know. You’ve twisted my arm; I may sacrifice some horses and just get the Mugen box and be done with it as it’s mostly intake noise that I fail on. I have a KPro so could have a map for Mugen intake for noise restricted tracks and then a Gruppe M map for little to no drive-by limit circuits - switch between the two accordingly.

As always, really appreciate your time for conveying your advice and helping me out - much appreciated.

Lewys.