Been to the dyno with PP-engine
01-20-05, 10:00 AM
#1
Senior Member
Thread Starter
Been to the dyno with PP-engine
Yes now my frien and i have been build a new 13 PP with the following parts:
9:4c:r rotors
Hurley 3 mm race seals
45 mm idia PP inlet hole
54mm idia primaries 600 mm long
Weber 51IDA carb w/44mm chokes 260 main jet 160 air jet
ProSpark distriburless w/4 coils
That's the baseline and we were hoping to have more than 297 flywheel hp than our previous best on gasoline and same carb. And did we managed? YES! 316 hp@9100 rpm torque 244nM@8000 rpm we are quite happy with those numbers!
We switched from 48 mm primaries to 54 and gained 11 hp timing from 21L to 22L gained 10 hp (T is 14) One thing we are confused about is when we took out our alu 7' tapered well flowing exhaust sleeves we gained about 10 hp! With around 60 mm in rotor housing and 54 mm in primaries it's a definite mismatch but we did gain hp! Any comments? Also for the first time with a IDA carby we gained 2-4 hp with sparkplugs from 7 all the way up to 11.5 R4118 NGK plugs no fouling just clean and good looking! Unfortanately we didn't have the time to test our new 56idia alcohol injection manifold but we will be back in March. Our previous engine made 285 hp on a 55 Weber and 313 on alcohol with slide injection so we hope for 340 hp on our new engine!
9:4c:r rotors
Hurley 3 mm race seals
45 mm idia PP inlet hole
54mm idia primaries 600 mm long
Weber 51IDA carb w/44mm chokes 260 main jet 160 air jet
ProSpark distriburless w/4 coils
That's the baseline and we were hoping to have more than 297 flywheel hp than our previous best on gasoline and same carb. And did we managed? YES! 316 hp@9100 rpm torque 244nM@8000 rpm we are quite happy with those numbers!
We switched from 48 mm primaries to 54 and gained 11 hp timing from 21L to 22L gained 10 hp (T is 14) One thing we are confused about is when we took out our alu 7' tapered well flowing exhaust sleeves we gained about 10 hp! With around 60 mm in rotor housing and 54 mm in primaries it's a definite mismatch but we did gain hp! Any comments? Also for the first time with a IDA carby we gained 2-4 hp with sparkplugs from 7 all the way up to 11.5 R4118 NGK plugs no fouling just clean and good looking! Unfortanately we didn't have the time to test our new 56idia alcohol injection manifold but we will be back in March. Our previous engine made 285 hp on a 55 Weber and 313 on alcohol with slide injection so we hope for 340 hp on our new engine!
01-21-05, 10:53 AM
#5
Rotary Enthusiast
iTrader: (1)
Join Date: Jul 2004
Location: Rocket City, Alabama
Posts: 1,035
Likes: 0
Received 2 Likes
on
2 Posts
My local sportscar club had a dyno day Sat 15 January. One of the guys shot some video, it is about a 40 Meg download, takes awhile.
www.TreesAndTurtles.com/2005TacDynoDay
My blue 13B PP road racer 1979 RX-7 is the last car on the 8 minute long movie. Just pure naturally aspirated peripheral port power - no turbo, no nitrous, just plain Chevron pump gasonline.
www.TreesAndTurtles.com/2005TacDynoDay
My blue 13B PP road racer 1979 RX-7 is the last car on the 8 minute long movie. Just pure naturally aspirated peripheral port power - no turbo, no nitrous, just plain Chevron pump gasonline.
01-21-05, 02:44 PM
#6
Senior Member
Thread Starter
Originally Posted by the_glass_man
That's awesome, can you post the dyno sheet? Also do you have any pictures of the engine setup?
Trending Topics
01-21-05, 03:38 PM
#8
Why were you confused when taking out the tapered exhaust port sleeves gained you power?
Sure they no doubt helped exhaust flow out of the port, but wouldn't having the port "step" from small to large as Mazda designed it help stop the pressure waves in the exhaust from causing reversion back into the engine.
Think of the power our rotaries have in the heat, volume and NOISE energy in our exhausts- lots more than a typical 2 stroke piston engine in which exhaust resonance tuning is CRUCIAL to having a decent set-up.
Yes, a performance rotary even has overlap like a 2 stroke doesn't it???
Sure they no doubt helped exhaust flow out of the port, but wouldn't having the port "step" from small to large as Mazda designed it help stop the pressure waves in the exhaust from causing reversion back into the engine.
Think of the power our rotaries have in the heat, volume and NOISE energy in our exhausts- lots more than a typical 2 stroke piston engine in which exhaust resonance tuning is CRUCIAL to having a decent set-up.
Yes, a performance rotary even has overlap like a 2 stroke doesn't it???
01-25-05, 07:03 AM
#12
Senior Member
Thread Starter
Originally Posted by Michael_Rudy
Is this with custom PP, or MFR housings?
01-25-05, 04:37 PM
#14
Senior Member
Thread Starter
Yeah i have some pic's of our slide injection manifold and our new 56mm with butterflies. I will post them in a near future when i got time. This winter i am very busy building 9 13B and one 20B engines for customers in Sweden!