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5 hours ago, vxsr33 said:

In regards to cats, would it be best to go for a venom 100 cpi cat or would a magnaflow 100 cpi cat flow the same?

Venom 100 cell is good, but go the 5" body. The 4" body seems a little on the restrictive side

On 04/02/2017 at 7:32 AM, Yeedogga said:

I too am 'stuck' at high 200's (I don't really care!) But contributing nonetheless.

289rwkw at 20 psi

- bone stock motor, manifolds

- 3076 .82 with 45mm ext gate on turbine housing

- 3" exhaust (proper 3") no cat, one cannon muff. Wastegate plumbed in

- Fenix FMIC (non return flow)

- no emissions gear

- 1000cc injectors

- e85

Im happy with it, but, like others im not sure what (if anything) is limiting the setup.

I had same setup with 256poncams and on 98 hit a wall at 280KW, since chopping up that exhaust I found a 2inch pipe inside the jap resonator, on E85 it still made 320kw on 16psi..   

Found this in Fordmods in a google search for venom cats, thought I would be of some interest as the reply is from their supporting vendor from Venom Cats

EVL098 wrote:
I run the venom cats on my Fairlane when I had it and they were great.
I am also running Venom cats on the XR8 now. Cannot fault them for the money.
While yes 100 cell isnt legal to the EPA the law in NSW is you must have a functional cat convertor if you car is 86 or newer. It doesnt say anywhere how well it has to work it just has to be functional.
As far as the EPA goes changing a cam is just as illegal as running a 100 cell cat. A cat wont clean everything up and if you go with a bigger cam it hasnt been tested and proven to comply with ADR's which is where the EPA gets you. Tuning a factory ECU with a J3 is the same story.
If the EPA want to do you they will one way or the other. I highly doubt many members cars on here are under the 90db required to pass the EPA either.
If you knock the guts out of a cat there is no excuse you could use and you will get raped if they ever checked it. Running a 100 cell you can plead ignorance and just get a notice to change it. Providing the cat is functional you should be fine.



Spot on  :wink: 

The big issue is with knocked out cats, as long as you have a functioning catalytic converter then you are ok from a roadworthy perspective. EPA on the other hand is completely different, and while the cat may be compliant (200cpsi or 400cpsi) like EVL098 said, it does depend on other modifications you have done, cam, tune etc as these will all change the emissions output.

The smell is a tell tale sign of decat (and a 100CPSI but not as bad). The 200CPSI is much cleaner.

Most tend to go for a 100CPSI as it is higher flowing and does give a little more volume than an equivalent 200cpsi. Whether that translates to more power though depends on your application, on an NA 6 the flow difference will result in a negligible gain, the difference is greater for a Supercharged/Turbo (especially Turbo) car. The DOHC motors though can sound a little raspy/tinny with a 100 but that is a trait associated with a lot of DOHC 6s and 4 cylinder vehicles when you open the exhaust up, muffler choice in this area helps immensely.

Also most 100CPSI cats will only be Euro 2 compliant. You can put a Euro 3,4,5 or even 6 coating on it but at the end of the day the substrate just doesnt have the density to be able to filter the gases effectively (unless it has a ridiculously long body).

The balance is between emissions and flow. If you are concerned about emissions the 200CPSI cats are great and offer the best balance between flow and filtering and on most applications will work perfect. Especially on a V8 running 2 cats as the exhaust flow is split, although the 100s do sound better on the 8s haha  :twisted: 

We also have the 400CPSI cats and they all have a Euro 3 coating and are legal on newer model cars.

If anyone has any concerns or queries just drop me a msg, more than happy to help  :D

 

  • Like 1

Heres another good explanation from Venom Exhausts from Aust Ford Forums

 
 
Quote:
Originally Posted by webbiegareth
Yeah I'll wait for XRCIST's feedback - it's more curiosity than anything smile.gif

My theory was that the Venom 400CPSI cat with the 4" body was bigger than the stock cat, and even with the same CPSI, the greater overall volume inside would allow for a bit more airflow.

I was happy getting a replacement stock ceramic cat (the full thing with the engine pipe etc), until I saw them on ebay for $300... ugggh. Or are they cheaper than that normally?

If the Venom cat with 400CPSI is better than the stock cat, and almost half the price, I'll definitely get it.
Hey mate, you are absolutely correct notworthy.gif 

Even though 2 cats are 400cpsi, they wont have the exact same flow properties. The main factors apart from the cpsi rating that determine flow are the body sizesubstrate length and inlet/outlet size.

A larger diameter substrate will allow more flow than a smaller diameter version, assuming all other specs are the same. The substrate is the point of restriction that slows the gases down, the more passages you can provide through this point for the exhaust, the better. 

The other thing you have to remember, the standard cat is made with a ceramic substrate, which is much more prone to melting and breaking internally than a metallic version. Metal versions can withstand higher temperatures and richer air fuel mixtures, and those with larger diameter substrates (assuming all other specs are the same) work even better, as the larger surface area handles the heat more effectively. Thats why i recommend the larger body ones for turbocharged vehicles, as they are usually tuned richer at WOT than NA vehicles.

The other key factor that determines flow is the inlet/outlet diameter. To put into perspective, a straight section of pipe can flow roughly 115 CFM per sq inch of area. With that in mind a 2.25" pipe can flow 408cfm, a 2.5" pipe 509cfm, and a 3" pipe works out to be 747cfm.
The larger inlet/outlet diameter allows for more flow so you can therefore have have the same emissions compliance but still gain in net flow. So you could even fit a 3" 400CPSI cat on your car and then taper the pipe down after the cat to suit the exhaust, and still be better off flow wise than the standard 2.25" 400CPSI cat.

The other factor is substrate length. All of the Venom Cats have a 10cm long substrate. I havent measured the length of the substrate in a standard AU Falcon Cat but i can imagine it would be much longer. It goes without saying that shorter is better in terms of flow.

In regards to emissions compliance...

You are right, a 100CPSI cat will not pass an EPA test (assuming the use of normal gasoline). Some brands may claim Euro 3 emissions standard on their 100 cell units but that doesnt mean it will pass the Euro 3 test. It may have the right makeup of precious metal content which is in line with Euro 3 standards, but the fact is the 100CPSI substrate just doesnt have the density to slow down and filter the gases effectively.

The 200CPSI units are much better, but then again some do fail (This can relate to the substrate length discussed before).

All of my 100 and 200 cpsi units have a Euro 2 coating on them. The 400cpsi versions are made to Euro 3 standards, which is applicable up to 2009, (more than adequate for AUs). You have all the strength benefits of a metal core cat with the capability to pass emissions. Again you do have to remember that emissions compliance is also affected by other modifications too.

Hope ive answered your queries, if you need any other info just let me know wavey.gif 

George
__________________
VENOM EXHAUST WORKS
  • Like 2
7 hours ago, vxsr33 said:

Will switching my standard looking highflow cat (unsure of brand, previous owner just said it was highflow) to a venom 100cell require a retune or will it be safe to drive?

No need, less back pressure is a good thing, means motor will be more efficient

  • Like 1

More is always better when it comes to cooling, but its better to think of things as restrictions  rather than walls.


I made 360rwkw on 98 through an Auto with a Blitz return cooler. Intake temperatures were about 40C in the dyno room.
Like most things (all things?) have a target set in mind before you start and aim at that and everything will seem simpler.

Also like most things, its better to pay a little extra for overkill, because really every single part in an engine setup is really just supporting the turbo to work its best.

Running a GT3076R well that will be the limitation to some extent. Someone making 280rwkw at 17psi on such a turbo is exactly what you would expect, this isn't indicative of a wall or restriction at all. If it was a GTX3076R running 28PSI on E85 making 280rwkw then it would be another story!

  • Like 1

Blitz return flow FMIC, 256 poncams, Snow Performance Stage III WMI [mainly to control knock], an older Boss SS cat [no idea of the cell size], GT3076WG on a HKS extrude honed cast low mount and a HKS 40mm external WG and just nailed 302rwkw at 18psi, so it can be done but it ain't easy!!!

 

23 hours ago, tridentt150v said:

Blitz return flow FMIC, 256 poncams, Snow Performance Stage III WMI [mainly to control knock], an older Boss SS cat [no idea of the cell size], GT3076WG on a HKS extrude honed cast low mount and a HKS 40mm external WG and just nailed 302rwkw at 18psi, so it can be done but it ain't easy!!!

 

Is that on 98 or e85? 

I made 328rwkw on E85 @22psi. GT3076R-WG, CRG Highmount Mani with Turbosmart Hypergate45 and Ebay Intercooler I think. Only made 280rwkw on 98 @18psi.

Hmmmmmmmmmm....

54 minutes ago, klutched said:

Is that on 98 or e85? 

I made 328rwkw on E85 @22psi. GT3076R-WG, CRG Highmount Mani with Turbosmart Hypergate45 and Ebay Intercooler I think. Only made 280rwkw on 98 @18psi.

Hmmmmmmmmmm....

Trident mentions cams so I'm guessing 98.

Cracking 300 is so much easier on jungle juice but your range will be like 200km. Not really feasible for a multipurpose car, unless you go flex like Johnny keeps on preaching... though it's a costly exercise if you're paying rack rates for your tunes

1 minute ago, V28VX37 said:

Trident mentions cams so I'm guessing 98.

Cracking 300 is so much easier on jungle juice but your range will be like 200km. Not really feasible for a multipurpose car, unless you go flex like Johnny keeps on preaching... though it's a costly exercise if you're paying rack rates for your tunes

It's a piece of piss haha... I want 300rwkw on 98 which the turbo should be able to do... 

I'm running flex fuel already.

98, I have WMI !!!

E85 is impractical for me, I do mainly country miles.  Hold up your right hand, count your fingers....that's how many E85 outlets are west of the mountains in NSW give or take 5:14_relaxed:

I cry when I daily my skyline... I'm pretty sure on 98 I get f#ck all more km's :/ I need a retune me thinks

I still get 9.6 to 9.8 l/100km, so around 500km to a tank, highway miles. 

  • 2 weeks later...

It's interesting seeing this thread as I had my car tuned this time last year and it made 280rwkw, after getting it about a month or two it started knocking, took it back late last year and 4 degrees of timing was taken out above 10psi to keep it safe dropping it to 250rwkw.  I was told it just wouldnt take sensible timing without knock and it had high IAT.  Just considering now if I bite the bullet and get a PWR or Plazmaman cooler and see if that fixes it, otherwise I have other issues.

Obviously I could just go to E85 but I just want get it running correctly on 98 first.

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