Sport 350 - Is a decat worth doing?

[Karls]

I’m considering these manifolds to delete the cats and make the car less emasculated:

https://aerieperformance.com/products/motorsports-headers?fbclid=IwAR3Y1k0Gy2nheYzExKRhQNZxZQs2YK09Mh8_ULwQS7nSNxSIHuPQs9EfPXU

I already have a 2Bular lightweight back box on the car.

‘Question is, what else do I need?

I assume I’ll need a modified Down pipe with a sports cat/flexi joint in.

will I need new lambda sensors with longer leads?

will I need to get the car mapped - is it recommended?

I can only assume by deleting the cats the car should perform slightly better?

Any advice appreciated, thanks.

[cuprapw]

Without re-map you will most likely lose power.

I lost 24bhp with a 2ubular EPK in my 410, I had to remap and add an air intake and then yes 476bhp

Stock vs 2bular (no re-map and no air intake)

Edited March 26, 2023 by cuprapw

[C8RKH]

Strange, I put 2bular headers on my Evora NA and gained around 35bhp.  You do need to drive the cars with the new headers on gently for around 500 miles to let the ECU recalibrate as it "learns". Did you do that?  Because after that "run in" period the car was like a different animal....

[cuprapw]

I did more than 500 miles as suggested by Jim, the power loss was still there, specially on the high end. Also, compared to your case, there's the factor of N/A vs supercharged.

Once I added air intake and re-map, it was like a re-birth.

My only doubt is if adding an air intake (still without remap) would have mitigated the power loss (or even provide a bhp gain)

[MrD]

Very interesting...

Are we talking decat or race cat? Also, who did the mapping please? I'm also considering fitting the EPK on my v6 cup paired with an alias23 kit and a lightweight 2bular backbox that I already have. But losing power is not what I'd like! Thanks.

[cuprapw]

Hi @MrD

We are talking about a high flow 200 cell cat. Not sure what role the air intake will play (if it will help to mitigate the power loss or even make you gain some bhp), but just with headers-ypipe and high flow 200 cell cat, the power loss is almost guaranteed. I'm pretty sure a decat will make it even worse

Regards

 

[MrD]

 

ok that certainly changes everything, I appreciate that this is advertised as something to protect the engine from the possibility of collapsing catalysts but power and torque gains are also mentioned...

Who mapped your car Daniel? I've read that the ECU is locked on our cars?

Thanks

[cuprapw]

@MrD I currently have:

Komotec EX-475 remap

Komotec Carbon Air box 

2bular EPK (headers, y-pipe and 200 cell cat)

GT Australia titanium exhaust 

 

Important to note that KT won't sell just the Air box and the remap. Given that I wanted to keep 2bular EPK as for me is the best what I did was to order the full KT 475 kit, I kept 2bular EPK and sold separately the rest of the KT hardware included in the kit.

Now the car is a missile:

[El-RGB]

On 25/03/2023 at 21:47, Karls said:

I’m considering these manifolds to delete the cats and make the car less emasculated:

https://aerieperformance.com/products/motorsports-headers?fbclid=IwAR3Y1k0Gy2nheYzExKRhQNZxZQs2YK09Mh8_ULwQS7nSNxSIHuPQs9EfPXU

I already have a 2Bular lightweight back box on the car.

‘Question is, what else do I need?

I assume I’ll need a modified Down pipe with a sports cat/flexi joint in.

will I need new lambda sensors with longer leads?

will I need to get the car mapped - is it recommended?

I can only assume by deleting the cats the car should perform slightly better?

Any advice appreciated, thanks.

@Karls

I have full Aerie exhaust, from headers, high-flow cat, y-pipe and the exhaust. Your car 350 should need the longer lambda sensors, but you can ask JasonF from Aerie to be exact. 

I also have Alias 23 intake, and I noticed a power gain; however, I haven't got a chance do a dyno, but the power gain is obvious, as I ran side by side with a full stock Exige S, I ran faster especially at the higher rpm (it is logically to believe with this setup, I lost initial torque, but the gain at higher rpm should be non-mistaken as the car breaths higher volume of air and it exits a lot better with smoother exhaust and both of the cats turning into one high-flow cat).

And I haven't done any remap at this point, as I followed all the run-in procedures provided by the Alias intake instructions (10 mins idle and the next 30-50miles ease on the run-in). Hope this is helpful.

Frank  

[Tex]

On 03/05/2023 at 13:10, cuprapw said:

@MrD I currently have:

Komotec EX-475 remap

Komotec Carbon Air box 

2bular EPK (headers, y-pipe and 200 cell cat)

GT Australia titanium exhaust 

 

Important to note that KT won't sell just the Air box and the remap. Given that I wanted to keep 2bular EPK as for me is the best what I did was to order the full KT 475 kit, I kept 2bular EPK and sold separately the rest of the KT hardware included in the kit.

Now the car is a missile:

You are running a similar set up to me I believe 

My original numbers were 477bhp and 386lbs/ft

A later test on a different dyno  only showed 463bhp but 393lbs/ft although this was with the 2bular QT backbox and not the Lotus OEM Ti one.

Either way, car is more responsive and torque feels much stronger 

[cuprapw]

I'm planning to get soon some actual performance numbers with a racebox mini. 100-160 and 100-200. 

There are good references in this youtube channel, and he uses a similar GPS

 

[Karls]

Some progress from my original post...I now have the manifolds/headers. These are the new version from Aerie Performance with their premium heat insulation.

And very nice they are too, lovely welds...nice to just look at and drool over.

Next stage is fitting & mapping.

Watch this space!

[Karls]

Had these fitted at Litchfield yesterday along with a remap. The car now sounds awesome with more go. I'm delighted with the outcome. It feels like a different beast now which is exactly what I wanted.

[Paul_D]

2 hours ago, Karls said:

Had these fitted at Litchfield yesterday along with a remap. The car now sounds awesome with more go. I'm delighted with the outcome. It feels like a different beast now which is exactly what I wanted.

I didn't realise that Litchfield could do anything mapping wise with Lotus cars? Was it a custom map?

[Karls]

Yes it was. Litchfield have a lot of experience in a wide range of cars...not just GT-R's and Impreza's any more! They had an Emira in for Nitrons & a Milltek whilst I was there plus M3 Touring, Aventador, 911's, McLaren. A good bunch of guys, led by Iain who is a real gent.

5 hours ago, Paul_D said:

I didn't realise that Litchfield could do anything mapping wise with Lotus cars? Was it a custom map?

 

[MrD]

 

I am rather surprised/impressed. How come they map these admittedly tricky to map niche cars and they are not boasting about it on the socials? Noone can offer a map apart from Komotec as far as I'm aware and they only do it if you buy their parts, which are not the best. 

May I ask for a before/after graph and fitting costs involved? Manifolds is something I was looking to having done myself but inability to map was a show stopper.

Thanks

[C8RKH]

There is a write-up in this months Absolute Lotus where they test drive a lichfield modded Emira and they love it @MrD. They even upped the power from 388 to 409 with the exhaust and freed up the mid range some more.

Great to see more people tuning and providing options for Lotus.

[MrD]

Game changer if this is proven to be a reliable way moving forwards. I'll start some enquiries, thanks!

 

[Karls]

5 hours ago, MrD said:

 

I am rather surprised/impressed. How come they map these admittedly tricky to map niche cars and they are not boasting about it on the socials? Noone can offer a map apart from Komotec as far as I'm aware and they only do it if you buy their parts, which are not the best. 

May I ask for a before/after graph and fitting costs involved? Manifolds is something I was looking to having done myself but inability to map was a show stopper.

Thanks

They really don’t need to boast about it on social media; they are busy on other more mainstream lines. Iain is a canny businessman. But I’m sure if you asked him he’d be more than happy to do the work.

I can’t offer you a graph as I never had it on the dyno before or after. It’s not professional of me to divulge fitting costs, I’d suggest you give them a call directly to discuss.

I wouldn’t hesitate to get the manifolds done; the oem ones are so restrictive when you look at them off the car! Plus, without the cats your engine bay will run cooler.

[MrD]

Fair, thanks Karls.