dyno data

 

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.

 

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.

 

19? 21? that's like the margin of error on the timing light and the distributor....

 

Bring out your dead!
My car has long been totaled by a murderous woman in a suburban, but while reminiscing I found this video and thought it belonged in here.

 

I am lifting this old tread...

I can not understand why to use smaller diameter tubes than the engines actual exhaust port?
Can some clever person explain this to me...

 

it is pretty simple, Mazda revised the FC engines to have these huge port outlets (~48mm, its not quite round), when the previous engines did not. even the racing engines have a small exhaust outlet, they used a 43mm port into a 43mm pipe.

so the pipe RB uses (2" OD, ~44mm ID) is about right, and Mazda's exhaust port is too big.

 

any more dyno graphs with the RB long primary ?