BDC Street port vs. stock port dyno comparison
 

It's been a long time coming but I've finally got a dyno comparison between a stockish engine vs. my Renesis street port. As some of you guys know, I've been experimenting on street port schemes for this motor for about a year and a half now. I've always been curious what the comparison between the two would be, what types of porting are effect, where the engine lacks and can best benefit, etc. and I think this is a big step in getting to know some of that. So far what I can tell is the engine needs intake, bluntly speaking. My theory is there's plenty of "manifold" but not enough "intake port". Simply speaking, the motor needs more air into the chambers. The four exhaust ports, even though they can be enhanced to a degree, seem to work just fine.

It went against my initial guess as to where the engine was deficient but it is a nice welcome surprise. I'm ready to push it to the next limit.

Attached is a dyno graph.

The first car was done in 2007 and was stock engine (fresh), stock ECU, with an AEM intake setup, catalytic convertor deletion, and all else stock. Basically a base mod car plopped on the dyno.

The second car, done more recently, is my porting job and heavy intake/exhaust mods.

Comments welcome!

B

Wow. Any other mods on the street port car? Where the cars dynoed on similar weather days?

They were done at the same place; I'm unsure on similar weather days though. I just can't really remember. Mods are as listed. Wanted it to be a legitimate comparison.

B

The most significant change in the port is the evidence of power not dropping off on the high end even though the overall horsepower and torque curves are moderately higher throughout the RPM band. This tells me there's still more to be had out of this motor fairly easily!

B

By heavy intake and exhaust mods on the second car do you mean 3" catless midpipe and 3" catback? Can you be more specific?

whoa.

Brian, Nice work! Any more details on the porting? Any tuning done on the ported car?

Thats very interesting. I can share with you that ALL the top RACE engine builders I have spoke with have told me there is very little gain. You have obviously found something and something big up top. I look forward to asking you more about this when I have a free moment. Packing for Mosport race rt now but couldn't help but comment. Nice work.

looking good man...
I cant wait to see what my engine does. I just have to work out all my little problems so I can get it on the dyno.

I have a cat delete and factory intake. So it should be similar to your first car. The dyno may be different though. We'll see. I'll give you a call when I get closer to that.

some people might disagree that a dyno from back in 2007 is a valid comparison for a number of reasons, too bad you don't have direct back-back testing but it is understandably not a cheap investment in time, effort, and money to accomplish such a feat

love your standard Renesis porting work (non-BP) though and wished it was legal for the class I run in, so this is just a general statement of possible opinion and not a knock against your efforts ...

It's also impressive that you aren't losing anything in the low-mid range compared to stock. I took a couple minutes to poke around on your site, and have to say for any gearhead, the porting pics are works of art!

http://bdc.cyberosity.com/main.php?g2_itemId=6891

Gorgeous work man...

I didn't know you could take that much meat out of those housings.

nice graph.

How does your porting differ from say Racing Beat? Does RB only port the exhaust port, yet you port the intake ports as well?

There we go Brian, Nice work man... This is awesome work, maybe we can do my engine one day lol

RB does all ports, however it is very very very conservative compared to what Brian has done.

Very nice curve!

Or lack there-of..it's pretty much just straight, lol

Wow.
Something was just confirmed for me!

Did you do anything with the LIM?
OD

I bet this would be real nice with FI

Any mass airflow numbers?

Was wondering how long before that question popped up ... ;)

as it approaches 9k the difference is huge - very interesting indeed .

Brian (or anyone else) how close is the stock/modified lower power, non-ported dyno numbers to what the market typically sees? I think I'm hearing you that this lower power, non-ported data is typical of what people do (intake and catback). Is this a correct assumption? Just trying to clarify the comparisons.

i feel that i made the wrong choice using the racing beat templates :wallbash:...:tear:

looks like when this motor pops...off BDC i go.

The non-ported motor is stated as being fresh, not sure if that means a fresh factory motor, a fresh mazda reman or a fresh stock spec rebuild. The mazda remans are known to not be very good.

Either way. The numbers are in line with a stock motor but a little low for a car with an AEM intake and no cat but not out of range.

With a decent tune, I would expect to see 190-195 peak RWHP on a good factory motor with no cat.

I think a better comparrision would be against another street port rebuild, like the racing beat. If someone has a RWHP dyno plot, it would be nice to see.

Here is the racing beat dyno they provide, but it is flywheel horsepower not RWHP. . Modifications include their reflash. http://www.racingbeat.com/manuals/11309dyno.pdf

Additionaly, a detailed description of Heavy intake and exhaust modifcations would be nice and was the vehicle tuned or is it on a factory tune?

Eitherway. The dyno graph looks good. I really like how the power does not drop off at the end. First time I have scene that.

Eric-- the Ga club guys with the usual bolt on mods--no tuning are seeing anywhere from 180-195 with fresh oem ignition parts. This is on a dynojet. There is a rare car that will come and get 200-205.

I take it that this port work does not modify any port timing?
I can see the future need of a better balanced (than oem) renasis assembly:)