That sounds like what I'm aiming for. Then later I'll add a supercharger. Woohoo!

 

hey ryan - i know i've asked this before but what mods have you done?

worn oil seals, i know that - hehe. full RB exhaust, no rats nest, electric fan. anything i'm missing?

if that's it, 112 is pretty impressive for the cost invested in mods.

is removing the rat's nest good for any power, or does it just eliminate various problems?

you gonna run at everett this weekend, btw?

/edit: now that i think about it, it seems weird that i'm asking all these performance questions after being on the forum for an entire year. all boils down to the fact that now that i'm confident in my little motor, i'm ready to start removing the shackles as it were.

 

There is minimal evidence that the average stock 12a will get 150hp at the flywheel with the usual header/exhaust and carb mods. It is possible with very extensive tuning and hours on the dyno. But how many 12a engines are tested that way.

Rear wheel readings is what we normally get and readings between dynos is significant. Most likely the reading is in the range 110-120 hp. What really matters is not the inaccurate measured hp but the impact on the 1/4 time as a stop watch is really accurate.

Addind a header/exhaust, modded carb and intake, taking off the air pump and adding a K&N filter knocked 1.8-2.0 seconds off my time. My best estimate is that indicates an extra 40-45 hp at the flywheel.

The port sizes are now the limiting factor. Adding a better fuel pump, carb and ignition will not pass that barrier. Port the engine, and its potential now with these improvements may give 40hp increase.

 

is there a common AFM that people swap on the EFI motors or is everybody a carb lover?

 

No, a stock carb can do it too, if it's tuned properly.

There's a dyno sheet on the Yawpower site detailing a Pro7 engine, making 151hp. That is entirely through tuning - Pro7 says no carb modifications allowed except for jets (he modifies the air bleeds too but they're not allowed to be adjustable), stock ports, stock internals, stock '81-5 manifold with shutter valve in place, and stock exhaust manifold with 2.5" pipe (no muffler) !

 

I find that hard to believe... from Yaw or anyone. If it is indeed true, I bet there's more than meets the eye to that setup.

 

I wonder if he has his special exhaust port tongues in there

 

Among other things ...

 

Pro7 rules are strict!

Besides it was Mazdatrix's engine! I doubt there'd be any "funny business" going on in there... it would seriously hurt their reputation as racers and engine builders if they were found to be cheating!

 

True, but you have to admit that a stockish (with different jetting and minus muffler) 12A RX-7 making 151hp is highly unlikely. I'm not saying it's not true, but most Pro7 guys could only dream of getting that...

 

Yeah but how many Pro7 guys are running engines that they grabbed from a junkyard, with no jetting changes, with stock fuel systems, etc?

That 151hp is from a heavily optimized carb (to the letter of the rules) and fuel system and a 100% new engine.

 

Seems like alot of work for Pro7 lol... looks good on Paul's site though.

 

It might be possible on a perfect engine. I have never seen a set of dyno figures for a range of stock 12a engines but think plus or minus 3-, 5% could be possible.

For example over 30 years ago I was involved in works Mini Cooper S cars. Engines within tolerences were plus or minus 5% output from standard. Only 1 in 100 cars came together such that they were a good basis for competion with all the legitimate variations coming together in an optimal way. Minor variations in the head casting were critical and only 1 in a 1000 were selected for a hand built motor. It was stilll a 'stock' motor!

 

ha HA!! Only 150? I talked to Stan at SDJ Motorsports (www.sdjmotorsports.com) and he builds ITA legal engines (stock porting, specified carbs, no porting manifolds or anything like that, etc..) and with some very restricted rules to work with, he's gotten like 172hp at the flywheel on his complete setup.

Now if he could use ANY intake manifold and ANY carb he wanted, I'm sure he could come closer to 180 or 190.

 

And then the fur started flying... Saint's alive, begorrah!!

 

Leason number one kids, how to say BULLSHIT, with the flag.



I'm calling your bluff, bust out with dyno sheet!!

 

BAH! HUMBUG!

Everybody knows you can get about 275 horsepower from a dead stock 12A 1st Gen.

All you need is the "rice" stickers that say you do.

 

Ok prof...



How did I do? Was that good?

 

very good! A little slow on the response, but nothing to worry about.

 

if it makes any difference...... my 12a is stock port, piece'o'*****(i mean pacesetter) header and exhaust, dellorto 48 carb, accel coils.... guess that's about it. i made 3 dyno runs at the indiana rx7 meet, 109rwhp, 117rwhp, 117rwhp in that order. whatever that is at the flywheel, i have no idea

 

wow!

did you port the crap out of the header before you installed it?

 

I did a 113 rwhp with a stock Nikki on a RP streetport...anyone recognize the name Ari Yallon? Cats and everything to pass emissions...too bad it's a rotting carcass in my driveway, now...

 

Time to get out the...

 

Now for a little rant. When are you guys going to realise that dyno numbers are not the be it and end all?

Dyno's are an invaluable tool when it comes to tuning and guaging the effect of modifications. But, dyno numbers are not an accurate way to compare horsepower between different vehicles because results can vary so much from dyno to dyno... I know from experience as do the dyno operators themselves. The only way to get an accurate comparison would be to run both cars on the same dyno on the same day.

This is even more evident when comparing results between the common Dynojet dynos you seppos have and the superior load cell type dynos used over here. The difference is around 15-20%.

 

load cell type dyno = chassis dyno ???