I was told by a few rotory builders that :

"Typically a bridge ported 12a (race) makes around 240hp a (street) ported 12a will make around 190hp. This is assuming you have a good intake(weber IDA or something) and good flowing exhaust (headers straight back with straight through mufflers)."


I was also told this "A 12A with standard intake and exhaust ports will not produce much power at all. If the engine has been properly bridge ported with a decent EFI system and a very good exhaust system it could probably produce near 200hp at the wheels."


My question is for 240 + horsepower n/a would I need to run race fuel ? Would it really be ideal for a street car or would 120-200 (fly) horsepower be more for the street ? How much could you usually make without having to go to race fuel N/A

thanks

 

NA you'd never need race fuel. The IMSA RXs usually ran 92 or less, and they were peripheral ported. Sounded gorgeous too.

 

yea, 150 - 160 hp max on stock ports in N/A form. get a turbo man.

 

240 n/a wheel hp is kinda asking alot form a 12a. Even if you have the funds to build a beast like that.. it would hardly be streetable. You might have to run race gas to extract the maximum hp form the little engine that could.
On a properly tuned 12a. With an agressive street port.. and fueling and exhaust to match.. you should be able to lay down around 170-180hp to the wheels w/o race gas. But lets hear some more imput for the rest of the board.

 

787b ran on 85 octane **** water gas. Lower octane is better for non turbo, low compression engines.

Marques

 

So about 200 flywheel horsepower with bridge porting and full exhaust, fuel, induction ignition everything right ? Thats not too bad for a 2000 pound car though

 

God the Jags were pissed about that, they had to spend so much more on gas to run LeMans that year and they still got beat.

 

Unless you are racing...
Jesus Padilla 9.92 second 1985 RX-7 13B N/A, Weber and race fuel. All motor record.
http://www.nhrasportcompact.com/2004...ay/050601.html

 

that would be methanol, a whole different animal. We are talking about c16 or something similar (high octane gasoline).

 

that thing is so unbelievably ported though that it wouldnt be anywhere near streetable. he launches at like 10,500 rpms!!! hahaha, but yes, it's possible. still not a 12a though

-zac




...... go turbo

 

I'd be willing to wager that Padillas car would still be competitive on pump gas. Not in the nines perhaps, but given how well the 787 and 792 (when it wasn't on fire) ran on pump gas it would still lay some incredible times.

 

lets stop getting off topic and help me! lol j/k..... thanks for all your help. If anyone has anything else to add I would appreciate it. So its really not likely to see a 250 horsepower (flywheel) mazda rideing around on the street as a daily driver.

 

Depends on what you want as a daily driver.

GTU teams were making 300ish HP with Weber carbs after fuel injection was banned. They lost 20HP but made it back with more aggressive porting.

I have a PP in the works but it is *not* for all out power. I'd be happy if it made 220hp but peak power is not what I am concerned with.

 

im sure there are people with bridgeported cars with over 250 at the flywheel that arent "streetable" but are driven on the street

 

so nobody has any dyno's? are these just guesses i'm hearing? the one dyno i got out of mine was only 124 at the rear. not that happy about it though, wanna do it again on a different dyno.

 

i had 165.1@ the wheels with my 81 gsl. street port 12a, dellorto 48, mindtrain stage 5 exh., msd blah blah blah

 

PP's should be more streetable than a BP... bridgey (generally speaking!) have LOTS more port timing than a PP. They need to since the BP needs to open sooner and close later to expose the same amount of port area that a peripheral port can.

 

I have been hearing a weber or holley carb.... RB header.. full 2.5 exhaust.... upgraded fuel pump... mabye an electric fan conversion to save alil off high rpms .. some upgraded coils would get ya to around 150 160 ish...

this can be done without any porting or engine work ? What about if the engine has only been worked on but everything I just mentioned was 100% bone stock... what type of power would it be making ? mabye 90-110 rwhp ? It might have been one of u guys on this web site who I spoke too and said that on aim...