RWDlover

Hey guys, do you mind sharing your dyno sheets of your AP1 with Tanabe Concect G exhaust? Those that have it ofcourse.
The purprose is not to evaluate the absolute gain, mostly to see the shape of the curves. I have mine paired with a 60mm test pipe and Toda header. Before the Tanabe i had a 70mm single with 70mm test pipe, vtec was set at 4500rpm, and it was pretty linear from 4500 to the rev limit. Drone was annoying between 3 and 4k rpm, so i decided to go with something quiter, knowing it will lose some power. With the Tanabe and 60mm test pipe, it gained with vtec further down at 3500, it picked up a lot of power and torque up to 5000rpm, remained about the same or minour loss from 6 to 9k, but there is a noticeable dip in power/torque centering at 5400-5500rpm that wasn't there with the 70mm setup, so i would like to see if other people are getting similar behaviour from their Concept G exhaust. After fitting the exhaust, i had to add a lot of fuel up up to 5000rpm and remove a lot of fuel around 5500rpm to bring the A/F ratio curbe close to 13 again, and very minour changes from 6k and up. The exhaust note and quality is great, along with more power down low too, but this dip is something i don't really like. It feels like vtec is engaging again at around 6200rpm.

s2000Junky

Sounds like my fuel curve with this exhaust, TP and stock header. I have to cut a significant amount of fuel at 5500rpm as well. I thought that was more of the oem resonate frequency of the stock diameter intake and exhaust though. Im good with it, because its one of the best sounding cat backs and the car is nice with a little more grunt down low without giving anything up in the top end. There is a surge at 6k even though my vtec is set to 3600rpm. Ive had this cat back for 8-9 years now. Same system I used with my high boost sc set up and NA both. No dyno with a stock exhaust before and after though sorry. Id be really surprised if someone has one to post since this is not one of the more common cat backs.

RWDlover

So it seems that's how this exhaust behaves. It's a pity, if it didn't have this dip at 5500rpm it would be just perfect. This is exactly what mine is doing too, surge at 6000 like vtec is engaging again (it obviously doesn't, i set it at 3500 with this exhaust, but it gives a similar feeling). I also have an Injen rep intake on mine.
By the way, i am not looking for before and after dynos, just any dyno sheet of an AP1 with this exhaust on, and a description of the mods if possible.

flanders

Is the rear canister on that exhaust just a basic straight through design or is there any weird baffles inside them?

RWDlover

It's straight through design, although the core (perforated pipe inside) is of a smaller id from the piping.

Chuck S

My car is different in many respects as it's a 2006 with the AP2 engine fed via a K&N FIPK and exiting via a 63.5mm Berk high flow cat into a Tanabe Medalion Touring exhaust. Gernby tuned with a 3600rpm VTEC and the power curve is "straight line" between 3600 and 8000 rpm dipping below that line slightly between 4400ish and 6000ish rpm. Above the straight line from 6000 to engine limiter. Smooth curves on the horsepower scale, nothing abrupt.

I'm thinking this is an internal engine gas flow effect, not caused by the exhaust past the header (?).

(I drew the straight line on the graph.)



-- Chuck

RWDlover

Thanks for the dyno. The Medalion Touring is slightly different design at the rear section but the dyno sheet is interesting never the less. Yours also has a slight dip at 5500, but it looks less pronounced (you can see it on the torque curve). The only thing i changed and got the dip at 5500 is the exhaust, so this is definetaly causing it. I don't know if the stock exhaust shows the same behaviour, but the 70mm single system i had before didn't.
Is the core of the mufflers in the Touring also undersized compared to the piping? (piping after the split)

s2000Junky

Im almost positive this is the inherent characteristic of the stock engine with stock 60mm dual exhaust as well, not a Tanabe thing. Its baked into the oem design. You just effected that by moving to a 70mm single shifting your gains/compromises somewhere else in the powerband. Pick your poison. On a relatively stock NA engine, I think the duals make a broader and fatter power curve overall. If your trying to eek out every available hp from 7k up, you probably were better off before.

Chuck S

According to Tanabe specs both the Concept-G and Medalion Touring dual exhausts show 60mm - 50mm piping which I assume is 60mm before and 50mm after the split into the dual outlets. 100mm decorative tip diameters on both but the smaller pipe is evident forward of that point.

Pretty sure we can look straight thru the both sets of mufflers (no baffles). Both register under 93dBA noise level with the OEM cat so I'm not sure what effect the different size muffler cans provides.

This is the oft-posted photo of my diffuser that also shows the Medalion Touring mufflers well. Piping past the split is under the diffuser so I can't measure it but recall it's smaller than the piping before it.



-- Chuck

RWDlover

I don't really miss the few hp, 3-4 i guess, i lost from 6 to 9k, i just don't like that dip/hole right in the middle of the rpm range.