At Bluespark we receive a lot of questions about performance modifications and what mods are the best for improving performance.
Alongside tuning boxes, ECU remapping, air filters and inductions kits, Sports cats or de-catting are one of the most popular modifications people carry out on their cars.
We had a customer return to us with his already tuned by Bluespark, 2.5 226bhp Ford Focus ST after having a decat fitted. After tuning and dyno testing his stock engine earlier in the year, we tested the car to show the difference this combination of mods would make to performance.
Dyno Run 1 - Stock vehicle with Bluespark System(July 2021)
As a stock engine with no modifications, the engine produced 214bhp and 329Nm of torque on the dyno, not too different from the manufacturer claimed 224bhp and 320Nm.
After fitting our Bluespark Pro Petrol unit and making a few tweaks to the mapping, our engineers were able to increase performance by 31bhp and 42Nm. Not only did we increase peak figures to 246bhp and 372Nm, our engineers also significantly boosted performance from 2600rpm to the red line.
The customer was very happy with the results, not just in the peak gains, but how the car drove, feeling smooth and responsive throughout the rev range.
The customer contacted us again after having had a decat fitted elsewhere, asking if we would be able to test the car again on our dyno.
Dyno Run 2 - Decat (November 2021)
On the first run we removed the Bluespark tuning box and ran a test with just the decat. The vehicle made peak figures of 240bhp and 334Nm. A good increase of 26bhp. Whilst the peak torque only increased by 4Nm, you can see torque gains of over 10Nm higher into the rev range.
As a side by side comparison, the improvements from the decat alone were fairly good. Now it was over to our engineers to reinstall the Bluespark tuning box and see what extra performance we could achieve.
With the Bluespark tuning box installed and a few tweaks to the mapping, the engine was producing an impressive 257bhp and 394Nm of torque, adding 17bhp and an extra 60Nm of torque. Looking at the dyno graph you can see nice clear and consistent gains right across the rev range.
Presenting the results to the owner it was clear that he was delighted with the results and for less than £300 (Bluespark Pro Petrol Tuning Box and decat), he had significantly improved performance, increasing power from 214bhp up to 257bhp and taking his torque from 330Nm up to 394Nm.
| Dyno Results | ||||
|
Manufacturer Claimed |
Stock Dyno Run |
Tuned Dyno Run |
Decat only Dyno Run |
Decat & Tuned Dyno Run |
| 224bhp | 214bhp | 246bhp | 240bhp | 257bhp |
| 320Nm | 329Nm | 372Nm | 334Nm | 394Nm |
| 165kW | 158kW | 183kW | 177kW | 189kW |
Based on this evidence the decat modification made a great difference to performance and certainly justified the cost. Not only did it provide decent gains on a stock engine, it also complimented the Bluespark Pro Petrol module well, allowing further gains in power and torque.
Decatting FAQ’s
What is a decat?
A decat is the removal of the catalytic converter, the cat is replaced with a straight through pipe which allows gases to flow more freely out of any exhaust. This improves performance, but increases exhaust emissions.
Is a decat legal?
A decat is not legal for road use, and will also result in an MOT failure. For a road car, a sports cat is a better choice. For a vehicle destined for track use, at the time of writing decats are still permitted.
What is a sports cat?
A sports cat is a catalyst that flows more freely than standard, giving nearly all the benefits of a decat, yet is often still able to comply with emissions requirements.
How a decat/sports-cat improves performance
Standard catalysts can restrict exhaust gas flow, building back pressure which reduces performance. Removing or upgrading the catalytic converter allows the exhaust gases to flow more freely out of the exhaust.
At Bluespark we cover most Diesel and turbo petrol Ford models and engines, whether you have the pokey 1.0 Ecoboost Fiesta or the grunty 3.2 TDCi Ford Ranger, Bluespark can provide a performance enhancing tuning box.
Visit our dedicated Ford tuning page for more information
