Jump to content
SAU Community

Recommended Posts

Hi Guys,

I have a Just Jap 3" dump pipe and the Kakimoto REGU 06&R 3.5" cat back exhaust. I was wondering what to do about a hi flow cat.

The three options are 100 cell 3" hi-flow cat, 100 cell 3.5" hi-flow cat or a transition from 3" to 3.5" (no cat).

It is going in a R32 GTST with the RB20 and will be running a Hypergear ball bearing hi-flow turbo (G2 or G3 trim, not sure yet) on the standard exhaust manifold.

It will be mostly driven on the street.

Let me know what you think...

Cheers Ange

_default.jpg

jjrdumpfrontrb_4.jpg

Edited by HCR32 type M
Link to comment
https://www.sau.com.au/forums/topic/476180-hi-flow-cat-recommendations/
Share on other sites

I'm confused. Where are you thinking of putting the cat? The Kakimoto bolts to the dump pipe right?

If the last is true, I would put a 3" cat in the dump pipe.

How are you going to transition from 3" dump to 3.5" Kakimoto?

Edited by Silverhks
  • Confused 2
28 minutes ago, Silverhks said:

I'm confused. Where are you thinking of putting the cat? The Kakimoto bolts to the dump pipe right?

If the last is true, I would put a 3" cat in the dump pipe.

How are you going to transition from 3" dump to 3.5" Kakimoto?

I thought the cat goes in between the dump and the Kakimoto?

I have both parts on the way, so I haven't physically seen them yet...

Edited by HCR32 type M

I'm still new to this platform. However, aftermarket dump pipes like that are usually designed to mount to the existing cat-back eliminating factory cats. If you want a hi-flow cat you then have it fabbed in as far down the dump as possible. This hurts emssions on cold starts but works just fine once warmed up while allowing the best flow for your turbo.

 

The specifics of this platform I could have very wrong though. I hope someone more knowledgeable will chime in soon.

Almost all dump pipes and cat backs assume the retention of a factory sized cat.

Thought 1.  100 cell cats are useless as cats.  Also not legal.  You might as well have a punched out fake cat as waste money on a 100.

Thought 2.  200 cell cats actually work.  Not as well as a proper cat, but they actually do something.  They are also not much more restrictive than a 100 cell cat.

Thought 3.  As you're only putting it on an RB20, you won't need to consider massive flow potential, so a 4" cat (rather than the more extreme 5" that people squeeze into RB25+ exhausts) will do the job.  That's a 4" cat matrix with 3" or 3.5" flanges to suit your other exhaust parts.

Thought 4.  It is very common to have to buy a cat with no flanges and get them put on to make all this shit fit together.

7 minutes ago, GTSBoy said:

Almost all dump pipes and cat backs assume the retention of a factory sized cat.

Thought 1.  100 cell cats are useless as cats.  Also not legal.  You might as well have a punched out fake cat as waste money on a 100.

Thought 2.  200 cell cats actually work.  Not as well as a proper cat, but they actually do something.  They are also not much more restrictive than a 100 cell cat.

Thought 3.  As you're only putting it on an RB20, you won't need to consider massive flow potential, so a 4" cat (rather than the more extreme 5" that people squeeze into RB25+ exhausts) will do the job.  That's a 4" cat matrix with 3" or 3.5" flanges to suit your other exhaust parts.

Thought 4.  It is very common to have to buy a cat with no flanges and get them put on to make all this shit fit together.

I will be fabricating what ever option I end up with.

So use a 200 cell 4" hi-flow cat and fab up the correct flanges to suit each end?

15 minutes ago, HCR32 type M said:

So use a 200 cell 4" hi-flow cat and fab up the correct flanges to suit each end?

Essentially, yes.

As to exactly which make&model of cat to use.....I'm not sure what the cool kids are running these days.  MetalCat was cool for a while.  I think it has been Venom more lately, but that could have changed.

Our 100cpi venoms on its way from george. originally received the 5" but our GTT sits fairly low and before even trying it on it seemed like it was gonna scrape on every speed bump. so sent that back and went with the 4" instead.

quality seemed great and priced bloody well. customer service was on point too. so yeah i reckon venoms where its at these days lol

and if anyone thinks it was a mistake sending the 5" back for the 4", please lemme know haha. i've read it shouldn't be a restriction til about 250-300kw, and ours is only about 200 right now

 

9 hours ago, GTSBoy said:

Thought 1.  100 cell cats are useless as cats.  Also not legal.  You might as well have a punched out fake cat as waste money on a 100.

Just a note on that, my 100 cell cat is working, and my car passed emissions with it (to the standards set by Nissan, that can be seen in the engine bay). I believe that there are bogus catalytic converters, and those that are truly working... :)

7 hours ago, rakka said:

Our 100cpi venoms on its way from george. originally received the 5" but our GTT sits fairly low and before even trying it on it seemed like it was gonna scrape on every speed bump. so sent that back and went with the 4" instead.

quality seemed great and priced bloody well. customer service was on point too. so yeah i reckon venoms where its at these days lol

and if anyone thinks it was a mistake sending the 5" back for the 4", please lemme know haha. i've read it shouldn't be a restriction til about 250-300kw, and ours is only about 200 right now

 

Cheers, is George on the forum or do you buy them online?

14 hours ago, Silverhks said:

See, I knew I was to new here to open my mouth. Apparently I never learn ?

 

At least I know better than to give legality advice...

Haha, yeah they're not like VAG or BMW.

18 hours ago, HCR32 type M said:

Cheers, is George on the forum or do you buy them online?

He might be on the forums dunno. I do know he’s on eBay Australia, is on FB, has a website just google venom exhausts Australia, and also +61 402 753 146 (publicly advertised mob). He has iMessage so you should be able to text him for free if u have iOS. Dunno if he’d ship overseas but worth a shot I guess. 

Tbh if we’re talking cats ur probably gonna spend a lot less just getting it done locally.

Edited by rakka

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Hi, is the HKS  Tower Bar still available ? negotiable ? 🤔
    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
×
×
  • Create New...