Prospeed Hi-Flow Catalytic Converters

[UnhuZ]

Re: PROSPEED Hi-Flow Catalytic Converters!

Hi,

i'm interested also. My NSX is a NA1, so i think the 200 one would suffice to pass the emissions test, but i have to confess that my main intention is reducing the noise of the complete exhaust, that i'm yet to buy but want to take advantage of the GB.

I have one favour to ask to UK primers, if possible obviously, to include me in their shipping package and after receiving the stuff, shipp it to me to Portugal.
The reason i ask this is that the shipping to Portugal from USA is high (probably a little higher than to UK) but the main problem is that i have to pay 40% over what's declared of customs for parts and shipping for anything outside the European Community, what escalates the price of anything i buy in USA.
I understand that i may be asking something that can make you guys a bit unconfortable, but if you can't do it, no problem at all :wink:

thanks to all,
Nuno

 

[Senninha]

Re: PROSPEED Hi-Flow Catalytic Converters!

Hi,

i'm interested also. My NSX is a NA1, so i think the 200 one would suffice to pass the emissions test, ...........but want to take advantage of the GB.

I have one favour to ask to UK primers, if possible obviously, to include me in their shipping package and after receiving the stuff, shipp it to me to Portugal.
thanks to all,
Nuno

Nuno, if we can get the UKGB agreed with suffiecient numbers and effective shipping then happy to help

regards, Paul

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

Hi,

i'm interested also. My NSX is a NA1, so i think the 200 one would suffice to pass the emissions test, but i have to confess that my main intention is reducing the noise of the complete exhaust, that i'm yet to buy but want to take advantage of the GB.

Hi No problem. If you have a test pipe now then the Hi-Flow cats will get rid of some of the raspiness and lower some of the decibels. I will have a sound bite of before and after for people soon. PM me for ordering info. Thanks.

Brian,

I've got 5 OBDII's to the UK please as per my earlier pm to you, plus 1 x OBDI but think I may have more for you.

CAn you let me have some options of shipping costs etc.

regards, Paul

Thanks for the help Paul. I will work on the numbers on the shipping. Could you PM me your postal code. Thanks.

 

[Senninha]

Re: PROSPEED Hi-Flow Catalytic Converters!

Thanks for the help Paul. I will work on the numbers on the shipping. Could you PM me your postal code. Thanks.

So thats now 7 OBDII and 2 OBDI inc Nuno's request. Can you look at shipping 10 units as I'm pretty sure we can fill the extra 2 units.

I can pm my shipping details but think that a business address will be more efficient, so leave this with me for a short while.

regards, Paul

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

So thats now 7 OBDII and 2 OBDI inc Nuno's request. Can you look at shipping 10 units as I'm pretty sure we can fill the extra 2 units.

I can pm my shipping details but think that a business address will be more efficient, so leave this with me for a short while.

regards, Paul

No Problem Paul. PM me all the details. Thank you!

 

[UnhuZ]

Re: PROSPEED Hi-Flow Catalytic Converters!

Thanks a lot Paul... let me know a value and i'll paypal it...to you or prospeed, whoever you guys find best...

So thats now 7 OBDII and 2 OBDI inc Nuno's request. Can you look at shipping 10 units as I'm pretty sure we can fill the extra 2 units.

I can pm my shipping details but think that a business address will be more efficient, so leave this with me for a short while.

regards, Paul

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

Thanks a lot Paul... let me know a value and i'll paypal it...to you or prospeed, whoever you guys find best...

PM sent!

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

Sneak peak of the 91-94 style flanges

More pics coming shortly. I will be out of town next week. I will have pics when I am back. I should have the first batch done by then. Those who ordered first will receive the Prospeed Hi-Flow Cats in order of payment. Thanks again guys!

We are still trying to fill the last 5 spots here on Prime. If you are interested PM me for payment and GB details! Thank you.

 

[MvM]

Re: PROSPEED Hi-Flow Catalytic Converters!

We are still trying to fill the last 5 spots here on Prime. If you are interested PM me for payment and GB details! Thank you.

Hi Brian,

Parts are looking good :smile:
But I still would like to know final weight of these converters, if they will pass emissions and what the effect will be on my power output before I decide (in a car with both Taitec header, GTLW exhaust and ProSpeed chip).

At the moment, there's nothing wrong with my OEM cats, so it would purely be a performance/weight oriented modification for me.

 

[UnhuZ]

Re: PROSPEED Hi-Flow Catalytic Converters!

Brian,

i just remembered...i will install F1 Headers that were sold by GT-ROM... how is the pipe diameter on your cats? the F1 ones are 50mm, which i think is 2 inches... can you match that?

thanks,
Nuno

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

Brian,

i just remembered...i will install F1 Headers that were sold by GT-ROM... how is the pipe diameter on your cats? the F1 ones are 50mm, which i think is 2 inches... can you match that?

thanks,
Nuno

If you wish to have a 2" diameter I can do that for you. :smile: As of right now we build them standard in 2.25"

 

[UnhuZ]

Re: PROSPEED Hi-Flow Catalytic Converters!

If you wish to have a 2" diameter I can do that for you. :smile: As of right now we build them standard in 2.25"

that is a little bit wider than the headers.. won't it affect somehow the flow??
i mean...the gases come in a 2" pipe from the headers..then expand to 2.25" inside your cats pipes (the cats themself are wider, and got to be) then go back to 2"...

on the other hand, the exhausts use to have 60mm piping, which is larger than the header's exit...

hummm... well.... i think you'r 2.25" size will be fine, because it's over the headers exit size, but equal or under the exhaust pipe size...:biggrin: :biggrin: :biggrin: so forget what i told here.....2.25" it is (your standard) :tongue: :tongue:

PS - excuse me and my thinking outloud

 

[goldNSX]

Re: PROSPEED Hi-Flow Catalytic Converters!

Parts are looking good :smile:
But I still would like to know final weight of these converters, if they will pass emissions and what the effect will be on my power output before I decide (in a car with both Taitec header, GTLW exhaust and ProSpeed chip).

I'll get one out of the first batch and let you know...:wink:

Brian,

I've already did the payment. Regarding UnhuZ post I'd like to get a 2'' as the Taitec and the Remus exhaust are this size too.

 

[ffffanman]

Re: PROSPEED Hi-Flow Catalytic Converters!

Questions, Questions, Questions.
You know me, I'll tear anything apart...
Thanks for bringing this product to the market place.
I think what you were doing was looking for feedback before you actually announce and produce this product.
It appears to me that there are many unanswered questions.
Well that could just be in my mind.
I see a lot of people throwing their money down for a product that I find untested and proven.
I know I will probably loose my own knee caps with my own baseball bat down in Portland but I must speak.
So here goes....
What pressure drops are we looking at between a stock unit and your various units?
What cfm (airflow) are you testing these at.
Assuming a person has a good conditioned stock unit, what power increase might he see if he is n/a and installs your unit.
What about supercharger or turbo applications.
A 6lb boost whipple running at 8000 rpm redline sucks in about 550 cfm.
We certainly can't use your 300 or 400 series, can we?
Or is it not about performance at all here and we are just cleaning the air for those test pipe user guys.
Plus maybe a peace of mind that maybe our original cats are broken or clogged up and with replacing them, we can get a few extra ponies or maybe loss some torque, who knows....
Mine have 110,000 miles on them using premium and midgrade gas and are clean as a whistle and you can see right through them.
Just a few comments and questions...
oh, ya, I'll probably take a couple sets....lol, to go with my two whipples.
Trev

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

Questions, Questions, Questions.
You know me, I'll tear anything apart...
Thanks for bringing this product to the market place.
I think what you were doing was looking for feedback before you actually announce and produce this product.
It appears to me that there are many unanswered questions.
Well that could just be in my mind.
I see a lot of people throwing their money down for a product that I find untested and proven.
I know I will probably loose my own knee caps with my own baseball bat down in Portland but I must speak.
So here goes....
What pressure drops are we looking at between a stock unit and your various units?
What cfm (airflow) are you testing these at.
Assuming a person has a good conditioned stock unit, what power increase might he see if he is n/a and installs your unit.
What about supercharger or turbo applications.
A 6lb boost whipple running at 8000 rpm redline sucks in about 550 cfm.
We certainly can't use your 300 or 400 series, can we?
Or is it not about performance at all here and we are just cleaning the air for those test pipe user guys.
Plus maybe a peace of mind that maybe our original cats are broken or clogged up and with replacing them, we can get a few extra ponies or maybe loss some torque, who knows....
Mine have 110,000 miles on them using premium and midgrade gas and are clean as a whistle and you can see right through them.
Just a few comments and questions...
oh, ya, I'll probably take a couple sets....lol, to go with my two whipples.
Trev

Hi Trev,

You again? lol j/k You always have questions and I like that! Hopefully I can answer a few of your questions. As of right now my 91-94 are built and completed. :smile: I am going out of town however but will be back next week and I hope to do a full install with first pics of the craftsmanship, sound and weight. I will also have the dyno graph showing the OEM cat vs. The Prospeed Hi-Flow Cats shortly there after. Per my manufacturer he has tested the NSX cats and have seen them to flow in the neighborhood of 245 cfm to 270 cfm. Based on the SOS website they have it rated at 261 cfm so I figure that to be fairly accurate. My manufacturer tested the 300/200 cell at 28" vacuum. The 300 = 368 cfm and the 200 = 437 cfm.

I expect to see HP gains with the Hi-flow cats, I'm estimating between 4 to 8 hp throughout the powerband. More importantly dropping 12 lbs from the rear and not having to worry about the smell and loud/raspy sound of a test pipe. They won't be street legal but they should pass the sniffer even in CA. For those who want to be assured the 300 cells will have no problems. In a boosted application I would recommend going with either the 300 or 200 cell only. Going Green is the rage right now and why not clean up the air and go with Hi-Flow cats instead of test pipes. If you have broken or clogged cats then you will definitely benefit. Even going to a set of new OEM cats will yield more HP over damaged ones. I hope that answers some of your questions. I am heading out of town for a week and will be back to post those pics I promised. They look great!

UPDATE

4 spots left! 2 pending. First come, first serve. Thanks!

 

[greenberet]

Re: PROSPEED Hi-Flow Catalytic Converters!

I look forward to seeing whether they net 4 - 8 horsepower. If test pipes net about 1 hp on naturally-aspirated engines, I'd be pleasantly surprised if metal core cats get you more than that.

When I installed new headers last year, I looked into my 16 year old catalytic converters which had about 130,000 miles on them, many of them being full-throttle miles. The converters looked like fffanman described - clean as a whistle. They also looked like they have ceramic cores. If that's the case, then they cannot get clogged up by melting - which could happen to metal core cats if you run a rich fuel/air mixture at full throttle (like my NSX does).

The catalyst layer seems to have burned off the ceramic cores of my OEM catalytic converters because my emissions are too high. If you need to pass a sniffer test (my car has a special exemption!) then the Prospeed cats may be a less expensive way to pass the test than buying new OEM cats. If they also weigh less than the OEM cats, great.

If they really do get you 4-8 horsepower as well, I'd think about buying some myself, but I would be worried about their metal cores melting over time during full-throttle runs, clogging up and actually costing me horsepower.

goldNSX - when you install yours, please take some pictures of the cores of the OEM cats you are replacing.


Edit: Ceramic core cats can melt, but ceramics melt at at 2000-3000° C, depending on type. The stainless steel cores in metal core cats melt at 1400-1500° C.

 

[MBANSX]

Re: PROSPEED Hi-Flow Catalytic Converters!

what is the CFM for the 400 cells?

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

I look forward to seeing whether they net 4 - 8 horsepower. If test pipes net about 1 hp on naturally-aspirated engines, I'd be pleasantly surprised if metal core cats get you more than that.

When I installed new headers last year, I looked into my 16 year old catalytic converters which had about 130,000 miles on them, many of them being full-throttle miles. The converters looked like fffanman described - clean as a whistle. They also looked like they have ceramic cores. If that's the case, then they cannot get clogged up by melting - which could happen to metal core cats if you run a rich fuel/air mixture at full throttle (like my NSX does).

The catalyst layer seems to have burned off the ceramic cores of my OEM catalytic converters because my emissions are too high. If you need to pass a sniffer test (my car has a special exemption!) then the Prospeed cats may be a less expensive way to pass the test than buying new OEM cats. If they also weigh less than the OEM cats, great.

If they really do get you 4-8 horsepower as well, I'd think about buying some myself, but I would be worried about their metal cores melting over time during full-throttle runs, clogging up and actually costing me horsepower.

goldNSX - when you install yours, please take some pictures of the cores of the OEM cats you are replacing.

From my experience we have seen many ceramic cores get clogged or pieces of the cores break off. The metal cores we use are less prone to clogging or melting. If your car has 130,000 miles on it and it still looks good that means it has been well kept. Usually improper A/F mixture, oil or coolant leak into the exhaust system, and or faulty O2 sensors will cause your cats to become clogged or damaged. We weighed the cats with all the parts not welded together to be just south of 10 lbs for the set!
We have seen different HP figures here on prime and in personal testing of the test pipes. Some have picked up 1hp while others pick up 5+ hp on an NA NSX and 10+ on a CTSC NSX. Figures will be different based on the set up that you have.


The 400 cell = 330 cfm

 

[ffffanman]

Re: PROSPEED Hi-Flow Catalytic Converters!

Thanks for the info and have a great week away.
Don't we all need that....
Thanks for the flows with a pressure drop of 28 inches of water column.
That is equal to one psi (1 Psi) or there abouts.
Actually here are the exact conversion numbers:
1 In. WG = 248.36 Pascals = .03602 Psi = .07334 In. Hg = 25.4 mm WG = 1.8628 mm Hg = .00245 Atm
27.761 In. WG = 6894.7 Pascals = 1 Psi = 2.0360 In. HG
So to summarize...

400 series flows 330 cfm with a pressure drop of 28" w.c. each cat.
300 series flows 368 cfm with a pressure drop of 28" w.c. each cat.
200 series flows 437 cfm with a pressure drop of 28" w.c. each cat.

The stock 3.0 nsx flows about 198 cfm @ 4000 rpm total. (99 cfm each cat)
The stock 3.0 nsx flows about 396 cfm @ 8000 rpm total. (198 cfm each cat)

A low boost whipple flows about 276 cfm @ 4000 rpm total. (138 cfm each cat)
A low boost whipple flows about 552 cfm @ 8000 rpm total. (276 cfm each cat)

Here is the pressure lose running a low boost whipple on a 3.0 and using a 200 series cat is:
A low boost whipple flows about 276 cfm @ 4000 rpm total. (138 cfm each cat) = 2.79" w.c.
A low boost whipple flows about 552 cfm @ 8000 rpm total. (276 cfm each cat) = 11.17" w.c.

We could say that the 200 series is your best bet for least restriction as long as you don't have to meet any emissions tests or standards.
Of course if you flow less than the stated cfm, then your resistance or pressure drop will be less.
Basic fan laws come in to effect here that state that static pressure increase as the cube of the cfm.
So at idle or low cfm, these cats will have virtually no resistance.

And then of course, all this being said, maybe our nsx engine likes a little resistance.....each car and case is going to be different.
No matter what, its all good and fun and I don't see anyone getting hurt.
I sure wonder what our stock cats flow compared to these.
Can't wait for some of your great tests!!!
I think Ed and I need to buy a dyno as well.
Trev

 

[Prospeed]

Re: PROSPEED Hi-Flow Catalytic Converters!

Thanks Trev for adding to the thread. Very informative! I agree with what you said above. :smile:

 

[nsxtacey]

Re: PROSPEED Hi-Flow Catalytic Converters!

HP gain is minimal, I'm more concerned with how it will sound with my exhaust. I noticed with my cats on it produced a high pitch resonating sound probably from the cells because when I had the test pipes on the resonating sound was gone. I put the cats back on and the resonating sound came back but not as loud because the cells are more clogged maybe.

OEM has how many cells?

 

[greenberet]

Re: PROSPEED Hi-Flow Catalytic Converters!

I sure wonder what our stock cats flow compared to these.

Some unsubstantiated rumor, grapevine-type numbers for the cfm of stock NSX cats can be found here and here.

Claim 1: 261 cfm at a pressure drop of 28" of water
Claim 2: 242.1 cfm at a pressure drop of 28" of water

 

[greenberet]

Re: PROSPEED Hi-Flow Catalytic Converters!

Using the figures above and assuming the stock cats flow 251 cfm at 28", I come up with the following back pressures caused by the catalytic converters:

3.0 NSX at 8000 rpm, full throttle
200 cell Prospeed cat: 0.21 psi (0.01 bar)
300 cell Prospeed cat: 0.29 psi (0.02 bar)
400 cell Prospeed cat: 0.36 psi (0.03 bar)
Stock catalytic convt: 0.63 psi (0.04 bar)

low boost whipple at 8000 rpm, full throttle
200 cell Prospeed cat: 0.40 psi (0.03 bar)
300 cell Prospeed cat: 0.57 psi (0.04 bar)
400 cell Prospeed cat: 0.71 psi (0.05 bar)
Stock catalytic convt: 1.22 psi (0.08 bar)

I don't know how much back pressure the rest of the exhaust system creates and therefore whether the cats' contributions are significant. Hopefully testing can show what impact they have on horsepower.

 

[MvM]

Re: PROSPEED Hi-Flow Catalytic Converters!

Guys, thanks for all the numbers.
But I do have a few questions about all these numbers.

As I understand, the higher the cfm number, the larger the amount of air/exhaust volume is the cat can handle right?
So, a higher CFM number corresponds to a less restrictive catalytic converter and hence, possibly, a higher RWHP-number.

Looking at the numbers from fffanman, even the 400-cell cat would be better than the OEM cats while still cleaning the exhaust well enough to pass emission?
So, if you have to meet emissions restrictions, the 400-cell cat would meet your goal best. Am I right?

 

[greenberet]

Re: PROSPEED Hi-Flow Catalytic Converters!

MvM, I think your assumptions are dead-on. Regarding which cat is best, theoretically, the cat with the least restriction that still allows you to pass emissions would probably be best. If you can pass the test with one of the lower cell-count cats, that may be even better.

Regarding horsepower, I found the following statement, "It is generally accepted by automotive engineers that for every inch of Hg of backpressure approximately 1-2 HP is lost depending on the displacement and efficiency of the engine, the combustion chamber design, etc." Since that's a quote straight from www.thrashercharged.com, it has to be true and can surely be accepted without question.

In any case, if they're in the right ballpark, then every 0.5 psi reduction in backpressure should get you somewhere around 1-2 hp. Swapping the stock catalytic converters on a naturally aspirated 3.0 for the 200 cell metal-core cats should get you a little less than that. But only before/after dyno runs can show what the numbers really are.

Edit: supposedly "Mark's Standard Handbook for Mechanical Engineers" states that an increase of exhaust back-pressure of 1 psi will result in a decrease of net power output from the motor of about 2 percent. That gets you about the same number of horsepower as the calculation above.