New Cat Back Exhaust Option - all stainless steel.

[David Czarnecki]

Just announcing our Design-Build-Go exclusive Kooks Built Cat Back Exhaust for the Grenadier. Take a look at the video. We are making the production tooling and should be availible mid to late September.

View: https://youtu.be/DyX3CQN9X4M?si=wjPWltnbUc4VuImE

 

[DaBull]

Just announcing our Design-Build-Go exclusive Kooks Built Cat Back Exhaust for the Grenadier. Take a look at the video. We are making the production tooling and should be availible mid to late September.

View: https://youtu.be/DyX3CQN9X4M?si=wjPWltnbUc4VuImE

Hi David,
Love the sound tuning on this. The sound is great and the back preassure burble is nice too.

Thanks for your detailed review and the comprehensive demo sound video.

Question, how is the sound when you are just cruising along at 45, 55, 65, 75 or 85 and not under acceleration?

1) Is there any noticeable drone sound at any given speed or rpm?

2) How is the sound when simply cruising on the freeway at 45, 55, 65, 75, 85? Does it drown out the sound system and enjoyment of the music?
Would you still arrive fresh from a long trip on the freeway or would the sound on the freeway tend to wear you out a bit when compared to the stock sound on a longer trip.

3) Would this void any warranty on the engine. I just found and posted the "Ineos Grenadier Body Builders Guide" on the forum a couple days ago, see link further below.
On page 93 it appears to show from where modifications could be made to the exhaust system. Perhaps review this page and talk with Ineos and the dealership to get a clear understanding if making the Cat Back Exhaust would or would not void an engine warranty or any portion of the warranty.

4) What is the exhaust and rear muffler or silencer made from, steel or type 304 stainless or 316 type stainless?

I look forward to getting the above questions answered.
DaBull

Link to "Body Builders Guide"

https://ineosautomotive.stylelabs.cloud/api/public/content/Body_Builders_Guide

 

[Texas Grenadier]

Following

 

[David Czarnecki]

The cab is very well insulated. Using a Decible meter we measured the cabin noise to increase by 1 to 2 dB though the rev range at moderate acceleration over stock. Cruising at all the speeds or cruise control I have not noticed a louder tone than 1 dB so it does not overpower the cabin or effect the enjoyment of listening to music. That was a big part of why this has taken 5 iterations. I don't think you can remove the muffler and resonator and have a balanced system without drone like some competitior systems. That's why we put in a smaller muffler to still quiet the vehicle during cruise for example. The entire system is 304 stainless which is not cheap.
We did 800 miles of testing with no negative effect to engine parameters or check engine lights which was what we anticipated as all of the engine montioring for emissions is before the cat flange. I have had the Grenadier at the dealership showing them 3 of the 5 iterations. Given it can be installed with all factory mount points they are willing to install if requested. I read the bodies builders guide and for Ineos to not approve a warranty claim they would have to prove the exhaust contributed to a failure. The Cat back system is the same diameter and allows for better flow, while following the factory mount points. I am not concerned about the system causing any negative effect to the vehicle.

 

[grenexplorer]

What’s the price point?

 

[David Czarnecki]

What’s the price point?

$2,299. There is a lot of 304 Stainless Steel. No welding and labor most people could do it themselves.

 

[anand]

Cruising at all the speeds or cruise control I have not noticed a louder tone than 1 dB

So approximately 7% louder than stock in the cabin

The Cat back system is the same diameter and allows for better flow, while following the factory mount points.

Being the same diameter as stock, I'm assuming there is no performance change, correct?

While I understand the vast majority of the restriction lies within the factory downpipe/cat combo, is there any alteration to the boost curve (able to achieve requested boost any sooner)?

Any reason you kept it stock diameter and not any larger?

 

[David Czarnecki]

So approximately 7% louder than stock in the cabin

Being the same diameter as stock, I'm assuming there is no performance change, correct?

While I understand the vast majority of the restriction lies within the factory downpipe/cat combo, is there any alteration to the boost curve (able to achieve requested boost any sooner)?

Any reason you kept it stock diI ameter and not any larger?

 

[David Czarnecki]

The dB level was measured with an actual meter not the one on a phone app that are marginal at best. I remember the base being about 70dB for stock driving at cruise which a change of 1 dB would about 1.4% not 7%. We are conducting more testing while the production hardware is being built while doing more promotional video. I will be using a stock Grenadier as well as ours. Kooks has the decibel meter and since its in the same town I live, should be easy. I will gladly post this once done. I feel the most ideal method would be to look at the measuring at different rpm intervals and compare to see where it is the largest delta. I find that the transmission tries to set every cruising point at about 2000 rpm no matter the gear. This is likely due to "best economy" setting in the computer.

You are correct the biggest change in performance would be in the downpipe and catalytic converter combo. We plan on tuning our Grenadier and changing these items in the future but that is not something the everyday Grenadier driver would do so not sense in really pushing that. Plus it opens a can of worms with warranty that I do not think the Cat back system is prone to. I do not think the R&D money spent on that would have any return to produce it. There is however evidence that this is a better flowing thus less restrictive exhaust as during deceleration, you can hear a "burble" and so forth on the video. I have been looking for a 4 wheel dyno on the east coast and have yet to find one for this application to perform a before and after. I found out the TRX guys for example take out the front driveshaft and run it on a 2wd dyno. Talking to several BMW tuners they said "DO NOT TAKE OUT THE DRIVESHAFT" and try this. Apparently it can harm the transfer case based on electronic inputs. But I am looking to see if there is a quantifiable difference. I feel under hard acceleration, the Grenadier pulls much sooner but again I need to figure a way to quantify that.

Basically in evaluating the design, the folks at Kooks have some software they use to look at flow and larger isn't always better. So in their evaluation, it was best to keep it nearly the same and even changing the volume of the muffler was engineered (this one is much smaller than the stock and different size diameter tips were also tested. They have extensive experience designing these systems and not an exhaust shop down the street. Take a look at the systems they build at www.kooksheaders.com. They do odder some green cats and other performance items in some of their kits. That down pipe and cat option has huge potential but first lets just get the phase 1 of the project out there and gauge interest. That is more a phase 2 type of project.

Thanks for the detailed questions. I hope my answers helped. More to come as we build and look to have to market by end of September. I always get asked if it helps miles per gallon and realistically I drive the truck differently now so I like to hear the exhaust and turbo spool so I tend to enjoy the experience a lot more and it bring me joy. At the end of the day I am willing to pay a little more for those smiles.

 

[David Czarnecki]

Hi David,
Love the sound tuning on this. The sound is great and the back preassure burble is nice too.

Thanks for your detailed review and the comprehensive demo sound video.

Question, how is the sound when you are just cruising along at 45, 55, 65, 75 or 85 and not under acceleration?

1) Is there any noticeable drone sound at any given speed or rpm?

2) How is the sound when simply cruising on the freeway at 45, 55, 65, 75, 85? Does it drown out the sound system and enjoyment of the music?
Would you still arrive fresh from a long trip on the freeway or would the sound on the freeway tend to wear you out a bit when compared to the stock sound on a longer trip.

3) Would this void any warranty on the engine. I just found and posted the "Ineos Grenadier Body Builders Guide" on the forum a couple days ago, see link further below.
On page 93 it appears to show from where modifications could be made to the exhaust system. Perhaps review this page and talk with Ineos and the dealership to get a clear understanding if making the Cat Back Exhaust would or would not void an engine warranty or any portion of the warranty.

4) What is the exhaust and rear muffler or silencer made from, steel or type 304 stainless or 316 type stainless?

I look forward to getting the above questions answered.
DaBull

Link to "Body Builders Guide"

https://ineosautomotive.stylelabs.cloud/api/public/content/Body_Builders_Guide

Did my response answer your questions? I wasn't sure it went in sequence in the post.

 

[anand]

The dB level was measured with an actual meter not the one on a phone app that are marginal at best. I remember the base being about 70dB for stock driving at cruise which a change of 1 dB would about 1.4% not 7%.

A 1dB increase is 7% of perceived loudness (very hard to distinguish), with every 10dB being double the loudness (80dB being received as double the loudness of 70dB).

And I appreciate the use of an actual meter, I used a real meter for testing on my sound deadening install as well

 

[pandawest]

Very Interested. I just want more sound, the Gren is too quiet. I'd order today if you had it available. Do you have a cold start video with your pipe on? Should sound better than stock on the cold start high idle. Thanks.

 

[David Czarnecki]

try this video at around the 4 minute mark.

View: https://youtu.be/DyX3CQN9X4M?si=Ex_kiYHb9LCaGtIy

 

[David Czarnecki]

Try this one too. Its outside.

View: https://youtu.be/-2R0yfhndtQ

 

[Kujo]

Try FABSPEED. They have an Ineos product that I might buy if I can find someone who is not afraid to work on the Grenadier.

 

[pandawest]

Thanks David, had a listen, is there a reason the camera has to be so close? By the way a bit more interior noise is not a bad thing under acceleration? You kind want to hear the exhaust / engine noise / turbo whistle.... its not just for the person walking on the street.

 

[pandawest]

Try FABSPEED. They have an Ineos product that I might buy if I can find someone who is not afraid to work on the Grenadier.

Thanks, looks like a sportcat for the B58. That alone would make a sound difference even with a stock exhaust. My Gren dealer would install, they are also an independent Porsche shop and other makes, but any independent shop would swap a cat for you. Not sure if it would need a tune to go with it.

 

[David Czarnecki]

Thanks David, had a listen, is there a reason the camera has to be so close? By the way a bit more interior noise is not a bad thing under acceleration? You kind want to hear the exhaust / engine noise / turbo whistle.... its not just for the person walking on the street.

 

[David Czarnecki]

I just set the phone there as it was one of my first videos and didn't realize to use a pro video setting. the phone kept turning the volume down. Secondly I agree that the sound in the cab does enhance the driving experienc. you can hear the shifts now and small amount of turbo spool.

 

[pandawest]

I just set the phone there as it was one of my first videos and didn't realize to use a pro video setting. the phone kept turning the volume down. Secondly I agree that the sound in the cab does enhance the driving experienc. you can hear the shifts now and small amount of turbo spool.

Thanks. Look forward to seeing your final product.