Ok so after ordering John's 2.5 Quiet X-Cellerator Exhaust with 100 Cell Cats and the wider single tips, its on the car.

First of all the X over of the pipes clearly has an effect on the sound unlike any other exhaust I have had to date; Europipe has been the nearest sound wise but it definitely sounds quite 993 ish or like a 4S with the Porsche sports exhaust.

There is no drone what so ever.

However, that said is still a tad loud for me especially with the kids in the back, so I am working with John on exchanging the tips for the dual tips asap

 

Hi Richard,

I'm pleased to see that you like our 2.5 X-cellerator cross-flow exhaust sound. As you described, it is a unique sound, unlike any other...and very fitting of the Porsche turbo. It is especially intoxicating at WOT!

I will remain in contact with you regarding the tip/ sound change via email.

Thanks for the positive review and I look forward to hearing from you in a few days.

 

Too loud? Are you kidding?? Heck - I asked John for a set of 3.0 tips so my 2.5 would be LOUDER! LOL - such a personal thing!! I love this exhaust. Hearing the turbos is my favorite hobby!

John - 3.0 tips! Ceramic black.

 

Can't wait for my 3.0 with 100cell cats to show up!!!

 

RichardCH - I know what you mean. When I'm by myself, I have no issues with John's 2.5 system. However, with wife and/or kids in the car, I find it to be a bit too loud. I'd love to stay in touch if you decide to go with the different tip option. I'm curious to know if that helps.

 

I am actually looking to replace my current exhaust (very loud Techart? with Eisenmann tips) with a quiet exhaust.

John was nice enough to answer questions for me but here are a couple more.
I hope that more members can be enlightened by your answers.

1- The most I plan on doing to my car are K16 Billets, how restrictive is your 2.5 quiet, compared to your 3.0 race? Any test results and sound measurements available?

2- It seems that for family trips this exhaust is still loud? Anyway to customize it to make it even quieter?

Thank you for the insight!

Enes

 

Hi Enes,

In answer to your question, our 2.5 quiet X-Flow exhaust is a high flowing, straight thru design that will work very well with your K16 billets. Obviously, a 2.5 will not flow as well as a 3.0, however, on smaller and medium sized turbos there is not a great difference in performance between the two systems and the difference is not detectable via seat of the pants driving. With K24/18G tubos and full supporting mods at 1.3 bar, a 3.0 will dyno about 25 peak HP higher from about 3200-4700 RPM's - a short 1500 RPM window. Up to 3200 RPM's they are equal on the dyno, at 3200 RPM's the 3.0 begins to make more power, it apexs at about 3900 RPM's and tapers down by 4700 RPM's to match the 2.5 again until red line. This 1500 RPM window goes by in a fraction of a second at WOT and in my experience a peak of 25HP for literaaly a split second is undetectable. I have driven these systems back to back many times, so I have a lot of experience with this aspect of testing.

That said, I use the 2.5 on my personal car because I prefer the quieter sound attributes in the ****pit, yet it still sounds great on the outside. I use it with my wife and family and find it is a great blend of 100 cell, straight thru design high performance and cabin comfort. Personally, I do not find it "loud" on family trips. There are a couple of things that I/we can do to make it quieter. First is opting for 200 cell cats - this will muffle/reduce the sound a bit.

Secondly, the dual tips that Richard is ordering are quieter than the large single tip, as the larger tip outlet will resonate more sound than a smaller tip. This is only true if one side of the dual tip is closed or "dummy", which is what we do on the "quiet" model. We can open up the second outlet on request and have done so in the past, but the system then becomes much louder and defeats the purpose of the "quiet" goal that most are looking for when they purchase this version. Personally, I prefer the sound of our 2.5 single tip over all others on this system. They were engineered, re-engineered, tested and tweaked over a dozen times to finally arrive at the version that would bring out and provide the best sound attributes that our 2.5 can offer. The dual tips lose a little of the character of our "goal" GT3 type sound we spend so much time perfecting, although they are in fact a little quieter, so they have their niche.

I hope this answers your questions adequately...

 

I said it before and I'll say it again - SpeedTech exhausts ROCK! The last system you will purchase for your 996/997 turbo.

 

I had my engine decklid changed from OEM to back to my GT2 (Misha) today and surprizingly that alone makes the exhaust another step louder especially inside the car, technically there is no drone like many other systems, it is just loud (but need to note my sound proofing under the rear carpets is removed)

 

If anybody has some Speedtech 2.5 " dual tips and wants to swap for the 2.5" Oval dual walled single tips please pm me

 

John you don't offer 200 cell cats on your website otherwise I would have gone for these ?

 

Hi Richard,

I forgot all about you removing the sound proofing...that would have a lot to do with the 2.5 being louder than normal...

 

Richard, We supply them on request. Let's email and see what I can do to get you set up...

 

Richard,

I had another thought - have you considered replacing the sound proofing you removed? I think that would make a world of difference and quiet the sound in the cabin dramatically. In fact, it would probably make it such that you would not have to do anything to quiet the exhaust, as it's pretty quiet in the car under normal circumstances with the sound proofing in place....

 

I found too that as the exhaust has aged over the past months it's become "seasoned" lets say, more mellow and well to me it's just awesome.
Are you sure you didn't have an exhaust leak at any of the components as I hear it can make it louder.
Of the five exhausts I've had this one is the best and by far the most liveable.