Jump to content
SAU Community

Recommended Posts

Which front/dump pipe a cat should i go for?

BOS (batmbl)

cat 3" large body cermaric inside $230

and SS dump/front pipe - $380

= $610 all up

Just Jap

SS cat 3" (xforce) flows 570cfm $160

and dump/front pipe SS - $250 +p&h

= so roughly $450 if del is $40

Is there any real difference between BOS and JJR? THe cats would be roughly sam size, but the dump/front pipes would there be much difference between these, cause its an extra $90 just to go for the BOS one....

I know that the BOS front/dump is proven to add 16rwkw and, would the JJR one give the same kinda power?

Link to comment
https://www.sau.com.au/forums/topic/169713-which-one-is-better/
Share on other sites

u could even get a flyn dump front but its not split. IMO it would be better than both the above mentioned as the airflow never gets interupted from the turbo to the cat.

and about the cat, just get teh JJR 1, it is more than sufficient and is rated i belive to 250odd RWKW. correct me i im wrong. unless you plan on more than that then lash out and spend like 400 on a cat.

split dumps try to minimise the turbulence in the exhaust which you get when the wastegate opens. it separates the two flows until further down the pipe. therefore the longer the two flows remain separate and the smoother the two pipes join up, the better its gonna be. you need to look at the pics of each.

i dont know bout the fitment of either model. you also need to consider where the o2 sensor hole is placed. im guessing that both have good fitment and design* so its probably up to your tastes

*note i havent actually seen either of these pipes

just get a 3inch front/dump pipe in a mandrell bend made up from your local exhaust shop and get a 3 inch metalic hiflow cat while your there. should cost you about 800ish including labour. im not using a split dump, complete waste of money if ur not going past 240rwk.(hardly no turbulance) if your gonna go past 240rwk youd need a non turbulance dump pipe.

I have recently purchased a BOS importing Catco catalytic converter & have no complaints!

The Catco product is excellent quality and is fully ADR approved. It also comes with quality gaskets.

I could not believe the difference in weight between my standard cat and the Catco item. This alone suggested the internals where considerably different.

Chat to Michael at BOS as you may only require the smaller body 3 inch cat which is said to be suitable up to 230rwkw.

The larger body 3 inch unit is best for vehicles over 230rwkw.

Which front/dump pipe a cat should i go for?

BOS (batmbl)

cat 3" large body cermaric inside $230

and SS dump/front pipe - $380

= $610 all up

Just Jap

SS cat 3" (xforce) flows 570cfm $160

and dump/front pipe SS - $250 +p&h

= so roughly $450 if del is $40

Is there any real difference between BOS and JJR? THe cats would be roughly sam size, but the dump/front pipes would there be much difference between these, cause its an extra $90 just to go for the BOS one....

I know that the BOS front/dump is proven to add 16rwkw and, would the JJR one give the same kinda power?

I have recently purchased a BOS importing Catco catalytic converter & have no complaints!

The Catco product is excellent quality and is fully ADR approved. It also comes with quality gaskets.

I could not believe the difference in weight between my standard cat and the Catco item. This alone suggested the internals where considerably different.

Chat to Michael at BOS as you may only require the smaller body 3 inch cat which is said to be suitable up to 230rwkw.

The larger body 3 inch unit is best for vehicles over 230rwkw.

Well atm i have 194rwkw on 11psi so ill need the larger body cat for sure

Check the grade of stainless used for both dump pipes, could be the reason for difference in price.

I have BOS dump and metal cat (706cfm), can recommend. :thumbsup:

Is there any real difference in the metalcat compared to the large body? i know cermaic inside for large bosy and metal for metal cat...but does this actually help in performace....would this add power if i went the metal cat?

==

Well atm i have 194rwkw on 11psi so ill need the larger body cat for sure

Is there any real difference in the metalcat compared to the large body? i know cermaic inside for large bosy and metal for metal cat...but does this actually help in performace....would this add power if i went the metal cat?

Not sure of the flow rate of the large body one, but I think the metal cat has higher flow rate. Yes you are right about the internals. If you ask Michael (BATMBL) he will be able to tell you. I assume the higher flow rate the less restrictive therefore allowing the exhaust to be extracted more quickly through the exhaust system, which will also allow your turbo to work more efficently creating more power.

The only mod I have on my R34 GTT sedan is the front dump pipe and metal catco cat from BATMBL and 3" Apexi exhaust, also a K&N panel filter, I made 166.4rwkw.

I think I remember you on from the 4 door cruise last weekend, were you the young guy talking to RCHOO in Warburton and didn't go up to Donna Buang either. I was the silver R34 sedan with the kids. :domokun:

lol yeh that was me :domokun:

Well you have seen my mods now and thats y im trying to get the front of my exhaust sorted out....but not sure which way to go, i wana try to get as much power out of this fron/dump pie and cat as possible, and make sure it flows well....

But ill talk to michael at BOS and see what he reckons

I also found out that the just jap one is only 3 inch where the seperate wastegate split joins to the bottom of the front pipe, whereas the BATMBL one is just after the dump part of the front pips, so more power to be had there for sure......but now just to work out for the cat

Thanks for the help Issy :P

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

    • Ha, well, it's been.... a bit of a journey. Things have taken much longer than I'd hoped. I'll probably put up a thread at some stage. Hopefully soon. The car's not done any kms since my update in June though, put it that way.
    • Here's the chart for fuel pressure vs. current draw, assuming your base fuel pressure is 3 bar and you run like 0.5bar boost on WOT, you should only momentarily hit 9amps here and there. (Ignore my prev post, I cannot read a chart these days it seems)
    • Those comp test results are not hideous. Whether they are accurate or not (ie, when that comp tester says 140 psi, is the real pressure120, 140 or 160?) is unknown to us. The state of the battery used to crank it over is unknown, etc etc. Many people around here would say that the absolute values and the spread are perfectly fine to just add boost and keep going. I personally would be happier with a narrower spread than that, but even the diff between 125 and 145 is not terrible. That one cylinder at 125 though, has probably copped some damage relative to the others. You should inspect the valves seeing as you've got it open. Do you know how to measure installed ring gaps? That, and an inspection of the rings themselves, is how you will determine whether they need to be replaced. If you're not good to do these things, take the block and the pistons and rings to a shop that is, and ask them for the go/no-go on them. Do the bores need a hone at all? If so, you might well be justified in getting some different pistons in order to get away from the ring supply problem. Whether you're happy to spend a lot more money right now, on more gear, rather than less money, but an amount that looks stupid given that you will only get a handful of rings in exchange for that money, is for you to decide.
    • also possibly backed up to my filler and shat down it! 🤣
    • Ok so i would love some advice here please, i purchased an R33 a few months back and its had a few mods done to the engine, its an RB25det running a Master ECU, 1200cc injectors, bigger turbo, oil cooler, oil filter relocation kit, Spool H-beam rods, acl/ross pistons. When i removed the motor from the vehicle (as its getting a respray) i thought i would compression test it and these are the following results. Cylinder 1-145psi, Cylinder 2-143psi, Cylinder 3-125psi, Cylinder 4-145psi, Cylinder 5-140psi, Cylinder 6-135psi this test was done with the motor on the ground and powering up the starter motor. I dropped the sump and found broken oil squirters on cylinder 3,5 and 6. I was told my rings are probably worn so i stripped the motor completely to get a new set of rings for it. The trouble is no one has these rings anywhere and they have to be custom made by Ross over in the states and will cost about $600+$200 delivery. My question is how can i tell if my rings are at fault and if they are still ok and is this price ok for a set of rings?
×
×
  • Create New...