Lasse wankel

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!

the_glass_man

iTrader: (2)

That's awesome, can you post the dyno sheet? Also do you have any pictures of the engine setup?

Kahren

iTrader: (13)

this is all measured at the engine or was the 316 at the wheels?

frode

At the flywheel.

speedturn

iTrader: (1)

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.

Lasse wankel

I only have the numbers with 100 rpm increasements no curves yet, but hopefully a friend of mine is gonna plot it. I took some pictures on the engine standing on the dyno room. I will ask my cousine to be my webmaster so he can post it! Oh i forgot to mention that we dynoe'd our 313 hp slide alcohol set up with a new 56mm idia butterflies manifold (old 62 mm). We gained 40nM now 260nM at only 6000 rpm compred to 220nM at 9000 rpm with old set up! Peak hp peaked in at 9000 rpm but only 296 hp because we forgot to bring our 54 mm dyno header (which we had on our carby engine on Sunday.

DelSlow

iTrader: (2)

Its Joe Dirt! at least hes honest... Video was badass

BLUE TII

iTrader: (9)

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???

Rotarx7

iTrader: (3)

wow! thats really impressive. that just makes me want to get my act together and rebuild my pport. $$$$ is all i need =(

Michael_Rudy

Is this with custom PP, or MFR housings?

Rotarx7

iTrader: (3)

mine is custom. THe dudes car in the video?? i have no clue

Lasse wankel

The engine uses our own made PP housings made from stock 1978 housings.

Kenku

Pretty good numbers, there!

The mention of slide injection mention reminded me of a question I had about those things a while back; did you ever dig up any pics?

Lasse wankel

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!

Kenku

Cool, good to hear you're keeping busy. Whenever you have time or something, as I'm far from in any hurry. Just remembered, is all.

speedturn

iTrader: (1)

I am the guy in the video. My PP housings were made by Nick at Rotary Reliability & Racing in Santa Anna, CA. Back in 1984, Nick set a Bonneville land speed record in his Killer Bee 13B RX-7. I did the motor assembly work, and other tweaks here and there. His porting produced a pretty flat torque curve from 5500 to 8500 rpm, and as you can see from the video, a peak of 323 rwhp.

I use a massaged Weber IDA carb, but I would be very interested in seeing pictures of the flat slide injection setup.

DriveFast7

iTrader: (1)

Those are real good numbers Tom. How much do you think @ the flywheel? What size chokes?

banzaitoyota

I am interested in the flat slide also. My PP will be running the EFI Hardware 55mm IDA TB from Tweakit with a Haltech E6X.

speedturn

iTrader: (1)

Drivefast: Here is a picture of the venturies from Feb 2004 when the same carb was on my 12A PP; IDA venturies were too small. The ugly spliced box tube brace to clear the carb has now been replaced with a correctly sized and curved piece of round tubing.

This pic is with the air box off; I don't remove it very often; it has been known to suck in dogs and small children.

PDF

Venturies look to be about 42 or 43mm?
Nice ram tubes.
Whats the pipe going into the top of the float chamber?

speedturn

iTrader: (1)

that was last year's setup when I was using oil injection + premix

Siraniko

iTrader: (13)

Lasse wankel

Nice pic! To me it seems that you have modified the booster length, it seems to be more of a DCO type short booster. The IDAs are longer. How much torque was the motor producing and at what rpm?

crispeed

[QUOTE=Lasse wankel]Nice pic! To me it seems that you have modified the booster length, it seems to be more of a DCO type short booster.

How about no boosters and anular discharge venturies!

Kenku

Can you actually buy such things? I keep hearing vague whispers of annular discharge venturis on Webers (that and noticing places in rule books where they're banned) but never any evidence... well, them and floatless carbs.