2bular full system with HJS

General General Lotus Talk
1

Am very likely to replace my inherited 2bular backbox (that is too loud for me) for a full system with HJS.

Is it worth doing the full system or should I just replace the backbox?

I want something that is quiet, and absolutely track permissible but ideally had a bit of fruitiness to it.

Has anyone got the full system and with HJS or heard a car with that?

Edit to add: have a TRD air box, 2zz engine.

(I know Jim’s not everyone’s cup of tea, but he’s good for me, so would prefer the post avoid comments about Jim and just stick to the metalware :blush:)

2

Is it the exhaust or the trd? MyS2 was fine on track until a trd was fitted and let a lot more charger whine out and it popped and banged way too much for me (and the black flag man).

My exhaust was a Tullet repackable which I don’t think you can buy any more.

3

Pops and bangs, I miss that with the old Stage 2. Current Larrini is track friendly, makes a nice noise but just wish I had some more drama.

4

I have a NA 2ZZ so may not be very helpful to you, but my 2bular 4-2-1, HJS and GT3 H2 backbox with through-diffuser exit came in at 98DB, 6000rpm static test at Cadwell Park. It makes a great noise - I had compliments about my ‘Honda conversion’ that other drivers thought I must’ve had done based on the revs, sound and performance on the day… Sounds angry, clean and meaty, but not loud or boomy. I’m very happy with it and would order the same again.

5

Yes! 98 static would be too loud. I’d want it closer to 90. Not sure that is possible with the 2bular - but I really want a 2tbular.

I wonder if there are ways the back box can be made to lower the noise?

6

I want something for my supercharged S2 with a deeper noise, no drone at motorway speed, burbles and pop drama on overrun /gear changes but able to pass the stricter trackday noise limits. I don’t know if that’s even possible!

7

That’s exactly what I’m looking for Andyzim and relatively quiet and definitely passes noise tests at track days.
Not asking for much am I :smiley: oh and perhaps a unicorn carrying a bag of hens teeth.

8

I have an S2 Cup 260 with Jim’s manifold, sports cat and QP (Quiet Performance) exhaust. It was static tested at 93dB at 6000 rpm at Brands without the extra bolt-on silencer. So far I have not had issues on track. It’s basically very quiet, nothing like the pops and bangs that the previous 2bular had, even with a dB killer - that was Jim’s 8 inch H1 repackable through-diffuser exhaust. Back then they were throwing me off trackdays, whereas now I can drive without worrying about it. It’s also a lot quieter on the motorway etc, to and from the tracks. For reference I have since driven Donington and Brands with no issues, both of which had been troublesome with the previous exhaust.

Good luck with it. :thumbup:

9

Cheers Richard, that is good to know. (I do love the odd burble, pop and crackle though but guess that’s one of the trade offs).
Could you do me a favour and record the sound from inside the car and if possible from outside. It would be great to hear it.

10

Apologies, only just seen the response. It’s pretty quiet to be honest, but I can try to record it somehow… not sure when though - if we get a clear spell I’ll get it out of the garage. Cheers.