HKS and Tomei both make cat-back exhausts for the RB26 GT-R. Here they're compared by chassis, with front pipes, cats and what the UK MOT checks.
The short answer
Tomei's systems are titanium and much lighter than stock, while HKS offers stainless and titanium. On a road car, pick a quieter system and keep a cat.
What the UK MOT checks on an exhaust
- Noise: it mustn't be unreasonably louder than a similar car with a standard silencer in average condition.
- Security: an insecure part of the silencer system is a major defect.
- Emissions: missing or obviously modified emissions equipment can fail, depending on when the car was first used, so ask your MOT tester.
- The law: a silencer must be kept in good working order and not altered to make more noise.
JASMA is a Japanese standard, not UK approval
HKS and Tomei both quote JASMA certificate numbers, and HKS's own manual for the Silent Hi-Power says it is designed for use in Japan only. A JASMA number shows a quieter road design, but it doesn't guarantee an MOT pass.
HKS for the GT-R, by chassis
We list the Hi-Power 409 for the R32 and R33, and the Silent Hi-Power, Super Turbo Muffler and Super Turbo Muffler Ti for all three. The Silent Hi-Power is the quieter road system.
Silent Hi-Power R34 | Super Turbo Muffler Ti R32
Tomei for the GT-R
Ti Sports is Tomei's titanium road system. Tomei quotes 8.9 kg against 19.5 kg stock on the R32, 8.3 against 18.9 kg on the R33 and 8.8 against 18.0 kg on the R34. Ti Racing has an 89.1 mm pipe, and Tomei sells it for off-road use.
Front pipes and cats
Artec says its twin 3.5" front pipe works with the factory cat or a high-flow, emissions-compliant cat. HKS makes a Metal Catalyser for the R32 to R34. Tomei's Ti cat straight pipe is for off-road use only.
Artec front pipe | HKS Metal Catalyser
Ordering
Tell us your car and system by email or the contact form, and we'll confirm fitment before you pay. HKS and Tomei parts come from Japan and usually take 1 to 2 weeks at the minimum.
Related guides
FAQ
Will an HKS or Tomei exhaust pass the UK MOT?
It can, but nothing guarantees it. The tester compares the noise with a standard silencer and checks the system is secure. A quieter road system, fitted securely with the cat kept, gives you the best chance.
How loud is the Tomei Ti Sports?
Tomei measured 99, 99 and 92 dB on the R32, R33 and R34, against JASMA limits of 100, 100 and 95 dB. Those are Japanese test figures; UK MOT testers don't use them.
Can I remove the catalytic converter on my Skyline GT-R?
Not on a road car if you want to pass the MOT. Removing the cat can fail, depending on when the car was first used, so ask your MOT tester before changing anything.