B-SerialRacer

Hi everyone! My name is Aris and I 'm totally new in this forum.
The last 12 years I own a European '99 civic ek4 vti with 175.000km on it. It has basic mods and bolt-ons such us:

Bilstein B6 suspension
HR springs
Spoon torque damper
oem airbox with a k&n drop in filter
accel spark plug wires
54mm handmade cat back exhaust
4-2-1 Custom headers: the 2 secondary pipes between the OEM 4 pipes and the catalytic converter, are resized to 48mm.

To begin with, I want some extra hp & torque, so in the near future I 'm planning to upgrade my valvetrain and after that I want to put the Toda A2 cams, with an obd2b to obd1 ECU conversion for the final tuning in the dyno. My goal is 180 – 185hp max. After that I want to make some adjustments in my transmission system (LSD and 4.7 final drive) for which I will go into detail in another post. But, before I move on to these modifications, I' m thinking to change my OEM ceramic catalyst converter first. The existing cat has never been changed because a metallic racing cat was too expensive back then. The basic idea is to buy a high flow cat (200 or 100cpsi), but I have the following questions:

1. To my knowledge, a high flow cat offers less resistance to the exhaust fumes when they come out. So, what about my back pressure? Is it possible to loose some torque in the low RPM?
2. Will this high flow cat lead to poor air/fuel mix? Is it necessary to change my ECU to obd1 in order to re-tune for better air/fuel ratio?
3.Will there be any significant change compare to my old ceramic cat? In other words, is it worth in terms of hp and torque gains?
4. 200 or 100 cpsi? Pros and cons.
5. Any reliable brand? I read that HJS is a good one. Kindly tell me your suggestions...

P.S.: Please excuse my rusty English

I m looking forward to read your valuable opinions.
Thanks in advance

Aris

Megalodong

B16A2 specs (copied and pasted):
DOHC VTEC 4 Cyl. 16 Val.
• Year: 1992-1995
• HP: 170hp@7600
• Torque: 116 lb-ft@7300
• Redline: 8200 rpm
• Displacement: 1595cc
• Compression Ratio: 10.4:1

A high-flow cat may net a small power gain. It will sound better (deeper) inside the cabin. Is it legal where you live?
Here's a thread that may help with your future intentions: https://www.civicforumz.com/engine-5...t-b16a2-11440/
A good dyno tune should get your HP close to where you want it. The torque specs are pretty wimpy though so hopefully that goes up as well with mods/tune.

White_EG1

B-SerialRacer

Thanks for your quick reply Megalodong!
To begin with, my civic it's not an EG b16a2 92-95 neither a JDM version, it's an EK4 b16a2 96-00, E.U. version
The specs are slightly different:
DOHC VTEC 4 Cyl. 16 Val.
• Year: 1996-2000
• HP: 160hp@7600
• Torque: 111 lb-ft@6500
• Redline: 8000 rpm
• Displacement: 1595cc
• Compression Ratio: 10.4:1

As far as the legality issue, I know for sure that the 200cpsi cat is completely legal in my country. For the 100cpsi I'm not so sure. Is there a big difference between 200 and 100cpsi? What version of highflow cat do you have? 100 or 200?

B-SerialRacer

Thanks for your reply White EG1. As I mentioned to Megalodong, I know for sure that the 200cpsi cat is completely legal in my country. For the 100cpsi I'm not so sure.
Kindly tell me your impressions with the highflow cat. Did you notice any significant difference in your car performance? Did you loose power at low/mid RPM range?

Megalodong

The highest flow: 0 cpsi...LOL.

That torque spec is even wimpier.
That's why I'm a fan of B20's ..more torque, funner to drive as they accelerate better and have torque acroos the entire bandwith.

White_EG1

White_EG1

Megalodong

With both engines naturally aspirated and all other factors equal (transmission, weight, etc..) a non-Vtec B20 with B16 head versus a stock B16 or B18.....A B20 will out-pull and especially from a stand still start. Add a B20 Vtec to the mix and there's no chance in a quarter mile. I don't care about the higher revs (redline) argument..torque is where it's at.