Racing Beat exhaust dyno compairisons
08-13-11, 08:28 PM
#327
Rotary Enthusiast
I know this isnt really related to your topic hyper but not many people have really tricked out gslse engines so youll just have to endure and/or enjoy talking to someone else who was willing to push the motor also.
I think the power band differences are pretty interesting, Im going to dyno again later to 9k to see what it peaks at how the power drops off, yours rises and falls off pretty quickly. I wish my rose that fast, it would be more drive-able I think and better for autox.
However if it falls off like it rises I think My car might be faster in a fast autox or road course if I wanted to beat the **** out of it and keep it between 7 and 9k rpms all the time. I dont think it would last long doing that though and not very practical.
I do wonder now if you were right about racing beats exhaust being restrictive compared to other options.
I think the power band differences are pretty interesting, Im going to dyno again later to 9k to see what it peaks at how the power drops off, yours rises and falls off pretty quickly. I wish my rose that fast, it would be more drive-able I think and better for autox.
However if it falls off like it rises I think My car might be faster in a fast autox or road course if I wanted to beat the **** out of it and keep it between 7 and 9k rpms all the time. I dont think it would last long doing that though and not very practical.
I do wonder now if you were right about racing beats exhaust being restrictive compared to other options.
08-15-11, 09:39 PM
#328
Old [Sch|F]ool
Lighter rotating assembly will show increased torque numbers on an inertial dyno, since there's less engine mass to slow down the engine's acceleration.
On a steady state dyno it makes no difference.
And yeah 120ft-lb seems low... for a 4 port. About right for a 6-port.
On the half bridge GSL-SE engine i found that there is basically no difference between 17 total and 25 total, with zero split. I run it at 25 mainly because this allows a lot of advance under cruising, since I'm still running a distributor. (It lives on 93oct in competition) I'd LIKE to run off of the trailing pickup, since the trailing can has twice as much advance, so I can dial back the distributor advance a hair and still have a lot of cruise advance, but I don't know how well the rotor phasing would be if I tried that.
On a steady state dyno it makes no difference.
And yeah 120ft-lb seems low... for a 4 port. About right for a 6-port.
On the half bridge GSL-SE engine i found that there is basically no difference between 17 total and 25 total, with zero split. I run it at 25 mainly because this allows a lot of advance under cruising, since I'm still running a distributor. (It lives on 93oct in competition) I'd LIKE to run off of the trailing pickup, since the trailing can has twice as much advance, so I can dial back the distributor advance a hair and still have a lot of cruise advance, but I don't know how well the rotor phasing would be if I tried that.
08-15-11, 10:10 PM
#329
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,796
Received 2,574 Likes
on
1,830 Posts
02-27-15, 02:51 AM
#331
Full Member
Join Date: Sep 2003
Location: Sweden
Posts: 135
Likes: 0
Received 0 Likes
on
0 Posts
I stuck the Genuine Racing Beat Header on a 13B in order to convert it from a 12A header to 13B and noticed that the tubes are smaller than the exhaust ports. Maybe this is only a problem when using 12A parts on a 13B, I've never paid attention to the exhaust ports 12A vs. 13B or held a 13B header. But the header needs to be ported before I install it.
I am, in fact, only going to be using the front section, and may not even do that given that I have a Sorento downpipe that looks like it can yield two rotary header stubs...
I am, in fact, only going to be using the front section, and may not even do that given that I have a Sorento downpipe that looks like it can yield two rotary header stubs...
I can not understand why to use smaller diameter tubes than the engines actual exhaust port?
Can some clever person explain this to me...
02-27-15, 09:29 AM
#332
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,796
Received 2,574 Likes
on
1,830 Posts
so the pipe RB uses (2" OD, ~44mm ID) is about right, and Mazda's exhaust port is too big.
Thread
Thread Starter
Forum
Replies
Last Post
