Maserati Forum banner
1 - 20 of 30 Posts

·
Vendor
Joined
·
4,728 Posts
Discussion Starter · #1 ·
All,

We've just introduced the Larini Systems Sport De-Cats product for the Maserati 4200 Coupe, Spyder and GranSport Models: http://www.formuladynamics.com/products/4200_larini_decats/4200_larini_decats.php

This bolt-in upgrade offers at least +18hp and +37 ft/lbs of torque, a staggering upgrade in terms of power output per dollar spent.

This product offers the best solution on the market today addressing the well known deficiencies of the 2nd set of restrictive factory catalytic converters and the compressed exhaust piping that runs underneath the steering rack.

Note that the method used to allow for improved flow underneath the steering rack while keeping the proper ground clearance was splitting each pipe into (2) sections which helps to create a vacuum that scavenges exhaust as well, thus improving flow.

I've tested this product first hand and can tell you that it's an easy (bolt-in) performance part that really frees up power for the 4200 Series Maserati.

Feel free to ask any questions, we're here to help.

Best Regards,
-- Jeff
 

Attachments

·
Registered
Joined
·
439 Posts
Wow Jeff, this is tempting! Those are some pretty big #'s to come from such a particular part of the exhaust.
Few questions for you:

I'm assuming there were some dyno's done to report these #'s?

And I'm also assuming there must be an undeniable notice of power increase as soon as it's mounted and you take it out for the first run..... especially with the torque amount gain.

Do you happen to have any pics of the OEM and this system up and mounted?
Sort of like a "before and after" comparison.

What is the difference between these and the sport cats? (other than the obvious that one has lower cell cats as opposed to none at all) Are both these parts made to go into the same section of the exhaust?
Will there be any problems passing local emission testing with the cat delete system?

And does there have to be any tuning done to the ECU at all to make these #'s?

Thanks.
 

·
Registered
Joined
·
744 Posts
Wow Jeff, this is tempting! Those are some pretty big #'s to come from such a particular part of the exhaust.
Few questions for you:

I'm assuming there were some dyno's done to report these #'s?

And I'm also assuming there must be an undeniable notice of power increase as soon as it's mounted and you take it out for the first run..... especially with the torque amount gain.

Do you happen to have any pics of the OEM and this system up and mounted?
Sort of like a "before and after" comparison.

What is the difference between these and the sport cats? (other than the obvious that one has lower cell cats as opposed to none at all) Are both these parts made to go into the same section of the exhaust?
Will there be any problems passing local emission testing with the cat delete system?

And does there have to be any tuning done to the ECU at all to make these #'s?

Thanks.
MaSeRaTi - I went the other way by removing the packing from the pre-cats and replacing the OEM secondary cats with the HPS sport cats. The difference is pretty amazing (Jeff figured about 20HP or more). The car revs more freely, pulls strongly and has a really nice exhaust note. Coupled with my Tubi mufflers and the FD ECM Chip, I was walking all over everything except the 430's at my last track day.

I went this way because I wanted to stop the overheat situation on the pre-cats. Moving the O2 sensors has been a real problem though so the tech needs to be carefull.
 

·
Registered
Joined
·
905 Posts
Is there an applicable modification like this for the QP? Or, does it not apply based on a difference in design?
 

·
Registered
Joined
·
439 Posts
MaSeRaTi - I went the other way by removing the packing from the pre-cats and replacing the OEM secondary cats with the HPS sport cats. The difference is pretty amazing (Jeff figured about 20HP or more). The car revs more freely, pulls strongly and has a really nice exhaust note. Coupled with my Tubi mufflers and the FD ECM Chip, I was walking all over everything except the 430's at my last track day.

I went this way because I wanted to stop the overheat situation on the pre-cats. Moving the O2 sensors has been a real problem though so the tech needs to be carefull.
Thanks for that info flashgordon.
Do you have DBW as well?
 

·
Registered
Joined
·
744 Posts
Thanks for that info flashgordon.
Do you have DBW as well?
I do. Not as big a difference as on the CC cars (mine is a 6MT) but still very worthwhile. It doesn't add power per se, but it brings what is already on tap, on a lot quicker. My seat of the pants impression, is that it quickens the car by at least a 1/2 second in accelartion to 60 because it makes the launch easier and shortens the pedal travel (e.g. you don't have to push your foot to the floor and wait for something to happen).
 

·
Registered
Joined
·
173 Posts
Jeff: 2 questions: 1)Will the car still be street legal (emissions-wise) and 2) do you have to make any changes in the O2 sensors?
 

·
Registered
Joined
·
1,405 Posts
Jeff- Since I already think my Tubi is borderline too loud for me, how do you think my car would sound with the De Cat pipes + OEM GS mufflers compared with what I have right now?
 

·
Registered
Joined
·
233 Posts
Tell us more! Emissions? Sound? This replaces all the cats or is the x-pipe section a totally different section? So all the restrictions won't be gone if I don't have the x-pipe right? Because right now I have NO mufflers, just resonated tips...
 

·
Registered
Joined
·
206 Posts
Not an exhaust expert here or an expert of any sort. But I'm trying to clarify this for myself and maybe others too. So correct me if I'm wrong...

So basically, the exhaust system on the Coupe/Spyder/GranSport is consisted of four "sections".

Section1 (#12 in diagram): Headers/Manifolds -- They also contain two pre-cats (well, one for each bank)

Section2 (#1 & #2 in diagram): Catalytic converters -- 2 Primary cats and 2 Secondary cats (so a total of 4 cats).

Section3 (#28, #30 & #31 in diagram): Center resonator in Coupe/Spyder OR X-pipe (with no resonator ??) in GranSport.

Section4 (#33 & #34 in diagram): Rear mufflers.

So, this new Larini De-Cat Pipes essentially are replacing those four factory cats (in Section2) with only two (primaries only; secondaries are now gone) instead and eliminating the compressed exhaust piping that runs underneath the steering rack.

I'm also very interested in this new product....only concern is with only 1 pair of primary cats will I pass the strict CA sniff test???
 

Attachments

·
Registered
Joined
·
722 Posts
...only concern is with only 1 pair of primary cats will I pass the strict CA sniff test???
Not only the CA sniff test but also the careful visual inspection! I have had techs spend 20 minutes verifying the presence of each emissions component on an exotic.
 

·
Registered
Joined
·
167 Posts
Hey Jeff,

Looks slick...
This would work fine with the OE Tubis?
Safe to say that adding these pipes would make even the stock exhaust louder...how much so..in your opinion.

Thanks!
PS get the spacers back?
 

·
Registered
Joined
·
439 Posts
Not an exhaust expert here or an expert of any sort. But I'm trying to clarify this for myself and maybe others too. So correct me if I'm wrong...

So basically, the exhaust system on the Coupe/Spyder/GranSport is consisted of four "sections".

Section1 (#12 in diagram): Headers/Manifolds -- They also contain two pre-cats (well, one for each bank)

Section2 (#1 & #2 in diagram): Catalytic converters -- 2 Primary cats and 2 Secondary cats (so a total of 4 cats).

Section3 (#28, #30 & #31 in diagram): Center resonator in Coupe/Spyder OR X-pipe (with no resonator ??) in GranSport.

Section4 (#33 & #34 in diagram): Rear mufflers.

So, this new Larini De-Cat Pipes essentially are replacing those four factory cats (in Section2) with only two (primaries only; secondaries are now gone) instead and eliminating the compressed exhaust piping that runs underneath the steering rack.

I'm also very interested in this new product....only concern is with only 1 pair of primary cats will I pass the strict CA sniff test???
^^Great post! Exactly my thoughts on this as well. Jeff, where you at bud?
 

·
Vendor
Joined
·
4,728 Posts
Discussion Starter · #14 ·
Larini

Wow... lots of questions. That's good! We actually took quite a few orders today so the word is out.

I'll do my best here and let me know if I've missed any questions.

With this De-Cat mod, we are removing (2) of the (4) installed factory cats and correcting the flow underneath the steering rack... This is where we are getting the increase in power and torque.

I am not an EPA expert, so please don't hold me to this... However, as I understand it: It is illegal to remove a properly functioning catalytic converter and that aftermarket catalytic converters are not legal for installation in California. So legally, CA residents have to buy new factory cats when they fail and we all know how expensive those are! I believe that residents in other states can replace failed cats with aftermarket versions.

As I've been informed by Maserati: These 2nd set of cats were added in the USA, compared to the European Spec cars, as the emissions tests that the Factory needs to go through in the USA include a cold startup.

Apparently the factory cats didn't pass during the first 30 seconds of a cold startup. So the factory added another set of cats as a quick fix instead of creating a solution that would offer performance and emisssions during startup.

TECHNOTE: Catalytic Converters need to warmup before they are fully effective and also the O2 Sensors have a warmup period before they read accurately and the ECM can make the proper corrections.

With that said, you should pass a sniffer test provided that your primary cats are functioning correctly and warmed up which is the standard sniffer test. This is because the first set of factory cats should be capable of cleaning the air well once warmed up. All cats are designed with this purpose and it's not difficult to achieve. With that said, Even if you only ran one set of Larini Sport Cats or FD Sport Cats, you should still pass the sniffer test. Both of these Cats are very high quality and capable of cleaning the emissions properly.

Regarding the visual inspection, my experience is that the emissions techs do not know anything about the Maserati and what is standard vs modified. I just don't think that they see nearly enough of them. However in all of these cases you will have at least one set of functioning catalytic converters. They'll know you have functioning cats regardless just by reading your emissions.

However, remember guys, this is an easy bolt-on, bolt-off part. It's meant so that you can go to the track and bolt up some power, they are often also called "test pipes". It will probably pass your sniffer test with just the one set of factory cats, however it may not be legal in your area for street use, so it's best to find out if you're concerned.

Now on to the good stuff... the difference (either with the Sport Cats or the De-Cat) is undeniable. There is noticably more torque.

The Larini Sport Cats and De-Cat are equivalent parts with the exception that the Larini Sport Cat section has Catalytic Converters and the De-Cat does not. So the Larini Sport Cats would be the cleaner of the two setups and they definitely will clean the air properly to get below emissions levels.

One thing worth noting. I actually experienced less in car resonance running the Larini Catalytic Converters and De-Cat over the stock Cats, which really suprised me. I think it has to do with the corrected flow underneath the steering rack. More testing will need to be done to confirm this.

We do have an ECM tune available for the FD Sport Cats, Larini Sport Cats and Larini De-Cat. This combination will offer you the best results however, it is not required. You can simply bolt-in and go.

Flash had failing cats (as is common for the Maserati) and welded in our FD Sport Cats. Again the difference is quite noticable, the car pulls much stronger all the way to red line. There are several options here depending on your situation and locality that may work for you. Feel free to call and discuss any of them.

No changes should need to be made to the O2 sensors. The connections are in front of the first set of cats in the header and just after. This section goes in directly behind.

Niteroi, the volume does raise a bit with this modification. I do think that you'll be more than safe with the OEM GS Mufflers. Larini is working on a new "Centre" Section that provides similar flow to the X-Pipe that is currently offered and available on the GS except that it will have some baffling to reduce the volume in the case that you have the complete system (De-Cats, X Pipe & Mufflers) and think that it's a bit too loud.

Regarding the provided diagram... This is not an accurate depiction of the US cars. In the USA, the Headers #12 and the first set of cats are welded to each other. They are not bolted together as in the diagram. Also, the 1st set of cats begin just after the pipes collect together and are descending towards the ground. The outlet faces back towards the steering rack. So it's really more of an "L" shaped Catalytic Convertor. Next there is a flange to connect the section that we replace. This section normally contains a pipe that squishes underneath the steering rack and then to the 2nd set of catalytic convertors.

So, there are (2) cats in the headers #12. There are also (2) more cats labeled #2 in your diagram. That makes (4) cats total on the USA 4200 Maserati Models.

The Larini Sport Cats / DeCat product replace the section including #1 and #2 with a pass-through pipe.

For the De-Cat: This reduces the total count from (4) to only (2) functioning cats.

For the Sport Cats: You will still have (4) total cats, (2) of them will be aftermarket and will far outperform the factory models in every way.

Regarding the QP or GranTurismo, the best upgrade available today is to install the FD Sport Cats, they work well on both models and since you don't have the same flow issues underneath the steering rack, it's pretty straight forward. It's just a boost of power with a high flow catalytic converter that far outperforms the factory model.

I hope this clears some questions up a bit!

Best Regards,
-- Jeff
 

·
Registered
Joined
·
1 Posts
Hi all, (new to the forum, from england)

Only owned my GS for 2 weeks now (had a M3csl previously)
Just had the clutch replaced, and now looking at exhaust options.

Was thinking about replacing the back box with either Tubi or Larini but have been thinking of another option to keep the GS rear boxes which are made by Tubi anyway and go for the de-cat!
The guys who replaced the clutch advise to keep the rear boxes on the gs and just de cat it!:)

Do you get CEL lights when going this route?
How loud is it? (I'm used to loud as had a GruppeM on my csl which was about 102db:D )
Anyone got a de cat GS?
Cheers
 

·
Vendor
Joined
·
4,728 Posts
Discussion Starter · #16 ·
Another note. We just heard back from the first customer to install the De-Cat and he's reported improved fuel mileage as well.

He's said that he now gets 50-60 extra miles on a tank of fuel! More installs will help to confirm these details, I'm sure.

Regarding installing the De-cats with stock mufflers, that should be no problem.

Best Regards,
-- Jeff
 

·
Registered
Joined
·
206 Posts
I hope this clears some questions up a bit!

Best Regards,
-- Jeff
Thank you for a thorough explanation as always.

The guys who replaced the clutch advise to keep the rear boxes on the gs and just de cat it!:)

Cheers
That's the direction I'm going. Since car is my DD, I don't want to make it too loud. Stock GS mufflers already have a good quality tone once you're in 4-6K rpm range.
 

·
Registered
Joined
·
206 Posts
Another quick question for Jeff or anyone who knows this stuff...

So, if I install this de-cat pipe (aka test pipes) that means I will only have two factory cats that are welded to the headers.

Question is: If (a big IF) these factory cats failed then I would have NO cats then, right? In this scenario what are my options then?? How often or likely will these factory primary cats fail??
 

·
Registered
Joined
·
265 Posts
U.S. Version of exhaust

The U.S. Version of the exhaust system

Text Diagram Auto part Line art Line

The connection # 35 for thermocouples, Is this port on the de-cats?
 

·
Vendor
Joined
·
4,728 Posts
Discussion Starter · #20 ·
Another quick question for Jeff or anyone who knows this stuff...

So, if I install this de-cat pipe (aka test pipes) that means I will only have two factory cats that are welded to the headers.

Question is: If (a big IF) these factory cats failed then I would have NO cats then, right? In this scenario what are my options then?? How often or likely will these factory primary cats fail??
Keep in mind that many cars run with only 2 cats and if they fail, you have no backups. The 2nd set of cats were never meant to be a backup, just to help clean startup emissions further. This is part of the reason that we do have emissions tests... to learn when our emissions systems are failing. Usually you'll know that you have a problem much earlier than that because you'll smell rotten eggs or notice a change in heat, volume or performance. These are signs that your catalytic converters are failing.

The truth is that if your primary cats fail, the particles of destroyed converter will clog the 2nd cats anyway. Both sets of catalytic converters would then need to be replaced to return it to factory spec.

In the scenario that your factory cats in the header have failed... the Larini Sport Cats pipe may be a good option in that they will clean the emissions very well and you would get improved performance. Of course the failed cats in the header would need to be cleaned out. Then your only catalytic converters would be those in the Larini Sport Cats Section.
 
1 - 20 of 30 Posts
Top