FelixIsGod29X

iTrader: (50)

Im having the last part I need besides the rebuild kit sent to me now and I need to get porting templates. I DID SEARCH but not great theards were found. This is going to be a daily driven 325-350rwhp car. So far I was set I the racing beat templates but then I though I should get everyone elses opinion. I dont want a really large port job, something medium/large or smaller. Anyone who can put in some input I thank a lot. - Nick

Old Slow Coach

At that power level, you don't need a really large port job. I know on a 13b-rew motor, you can make that much power on stock ports. You could call these guys and ask them what they think: http://www.pineappleracing.com/index...S&Category=109

FelixIsGod29X

iTrader: (50)

Yeah recently i was pretty set on pineappleracing intake porting template, now im looking for the best exhaust template for my situation.

Old Slow Coach

Racing Beat offers both a "street" or a "race" spec exhaust template. I think you'd be good to go with the "street" spec.

Judge Ito

my aggresive streetport template, has gotten great reviews and makes respectable horsepower..

Latin270

I can vouch for that!

Blake

I can't comment on other porting templates, but we have made 189.9 rwhp on an S5 NA block with SAFC and full exhaust.



Anyway, as far as the exhaust ports go...people put way too much emphasis on them. Sure, you benefit from opening them up a bit earlier but they don't need to be extraordinarily large. We do it more for the opening timing than for volume. The key to scavenging is velocity and energy. Opening the exhaust ports a few mm earlier adds energy that would otherwise be wasted into the cooling system as heat. In the exhaust stream it helps keep the freight-train of exhaust pulses moving with a purpose resulting in better scavenging (if you do it right). But there is already a lot of exhaust port volume in most cases. If you want to see what 'enough' is, go look at an MFR peripheral housing...those things are not that large, yet are big enough to handle a 300 hp race motor. Why would a street NA need more than that? In most NA application, we just use turbo housings (no diffuser) and do minimal exhaust porting...basically, just a clean-up with some added opening timing. If you do much more than that, you will probably just make the engine more peaky than it needs to be. Just my opinion.

Jeff20B

iTrader: (13)

Blake, I must take issue with your comment on the exhaust port timing in MFR peripheral port housings. I know Rob likes to use them as a counterpoint as well.

Wouldn't you say it's pretty fair that the MFR exhaust port timing is a good match for the peripheral intake port timing? But perhaps not as good for side port NA or turbo engines? How well would MFR exhaust ports spool a turbo for instance? And at what RPM would it be most efficient?

Not wishing to start an argument. Just curious why you guys like to make that comparison when there are so many other (obvious) differences.

RacerXtreme7

iTrader: (2)

Don't misconstrue Blakes post. He never compared MFR P-Port TIMING, he merely uses the size/volume of a 300 hp exhaust port as being amply big enough (size/volume) for 300hp, then why would a 150~200 hp engine need the exhaust ports to be bigger. It was an example that he merely cleans up the port and adds a bit of earlier open timing (were the hell you been during all my exhaust port timing discussions BLAKE?? as you support my theories {and also MAZDA, but some guys can't read I guess}). His comment about, "Opening the exhaust ports a few mm earlier adds energy that would otherwise be wasted into the cooling system as heat." is true as well, as there’s so very little torque that the rotor can apply to the eccentric because the moment arm that late in the power stroke is small, that getting the high velocity exhaust out sooner is less work on the engine pumping it out, gives it more time to get it out, and the higher velocity helps scavenging. I'm gonna stop here, as I've expressed these theories and how MAZDA and many upon MANY engine builders who's been around for decades use these practices and theories also.

I must agree also that the MFR P-Port housings timing coicides with its P-port intake and extremely low resistance high flowing supporting systems (both intake and exhaust systems). Again, hes not using those MFR housings for support in his port timmings (just example of port size/volume), as the MFR housings close EXTREMELY LATE and have HUGE port overlap (again, P-port intake and high flow supporting parts).

Hope I didn't put words in Blakes mouth, if so, sorry but it sounded like what I just wrote to me.

~Mike.........

diabolical1

iTrader: (3)

for the power levels you quoted, i don't think it really matters which template you use. as stated earlier, you could get that on stock ports. templates aren't going to make a good port job from a dynamic standpoint, so any increase in airflow will come down the talent of the person porting the engine. so i'd say just get whichever fits your wallet best (very rare to hear me say that ) and will be in your hands the quickest. if you you think it's likely that you're going to want really BIG power down the road, then by all means spend some time making a better-informed decision.

MikeFB

Sorry to be a noob, but when you say "MFR peripheral housings" - is there a company called MFR that makes them, or do you mean "manufacturer" or maybe something like "mazda formula racing"?

diabolical1

iTrader: (3)

Mazda Factory Racing