300 hp is impressive, but 180 hp at 3500 rpm is just sick.



I think I just got a design for the intake manifold for my SP...

i was just thinking abotu this yesturday, and have decided on hwo to make it for my pport engine, well c the results soon i hope.

i have done a bridge on just the aux port on a s4 engine, that engine was good for what it was, i raced it against my car alittle while ago, and was not any faster then my streetported s5 car. i also driven that same aux bridge car, and its nothing special like MS7 says its not worth it and the intake manifolds are not setup for it.



this was more of a trial thing since at the time there were no known aux bridges running aroudn and it was a good idea at the time and even if it didnt make much power it was atlest worth a try.



if you dont belive him and others that tell you aux bridge on stock manifolds wont do jack you can go ahead and do that yourself. i dont have exact dyno numbers for you for same exact engien runing with and without aux bridge port but i can tell that if there is a diffrence its not even wroth spendding the time bridging that aux port.



if you want a fast NA car a good place to start woudl be of course to get a nice exahsut setup and then get a real engien managment not something that was put together after all the years of somkign pot in college and makign a system for what is now called an rx7. and get some ITB intake setup with shorter runners.



also here are some DYNO numbers on what i am talking about, not only it will cost you less but it will be much less pain in the ass and a proen method already. plus you dont even have to open up your engine to get this power.



everyone is so quick to open up teh engien and start portign without realizing what portign really does or if its even nesseccary in their quest for what they want out of the car.



here are the pics and text with it.

http://24.2.177.252/cars/Manuals-Diagrams-...%20Sport%20ITB/

Hrrrm.



I have studied that article very carefully, and calculated the torque curve to see what is actually causing the effecte seen. Turns out that the carb and EFI torque curves are IDENTICAL, but offset by 500RPM.



That engine was street ported, so your arguament about opening up the engine doesn't quite hold true.



Just for the record, here is my Mk1 inlet. Mk2 will be based on GSXR throttle bodies.





BTW: what does 'not something that was put together after all the years of somkign pot in college and makign a system for what is now called an rx7' mean in plain english?

Hrrrm.



"I have studied that article very carefully, and calculated the torque curve to see what is actually causing the effecte seen. Turns out that the carb and EFI torque curves are IDENTICAL, but offset by 500RPM."



this coudl eb due to anything, even a slightest cahnge in diameter or where the actual plates are on both manifolds. also slightly more power from the haltech could be due to the the fact taht u can tuen EFI better.



"That engine was street ported, so your arguament about opening up the engine doesn't quite hold true. "



sorry about that part, i did read teh article a while ago and thought it was on a stock port motor, i am goignt to reread it now.



"Just for the record, here is my Mk1 inlet. Mk2 will be based on GSXR throttle bodies."



i can barely see antyhing in that pic its too small, looks like some shiny itb? https://www.nopistons.com/forums/pub...IR#>/happy.png





BTW: what does 'not something that was put together after all the years of somkign pot in college and makign a system for what is now called an rx7' mean in plain english?



i hate the stock ecu and all the wiring and everythign with the whoel stock mazda efi system, it was done back in the early 80s when the magic pills were popular. basicly my paint was beign if you have anythgin more then an intake and exahsut on teh car you really need an EFI or carb setup that is appropriate.

damn,.. well im inspired. 180 HP at 3500 rpm is 270 LB-ft of torque!,.. i didnnt know that was even close to possible on an NA...

Its entirely due to the length difference between the 2 systems. I calculated it. If you made the carbs shorter then they would make the same power. Lesson being that a 45mm butterfly is good for slightly over 200HP. If you made the inlets another 2" shorter and revved a bit higher that engine would easily make 230HP. Then make an inlet that can change length by +/-2" and you can have your cake and eat it. Although the top line HP looks good, 15 more HP in the midrange would often make a faster car on the street.



They are 50mm DCOE throttle bodies grafted onto a hurley SU manifold. Way off optimal but they fit nicely in the car and I get good cold air into them. They will be a good baseline to compare other things to.

that purple car is that what its in ? https://www.nopistons.com/forums/pub...IR#>/bigok.gif

Hi,

We manufacture cast manifolds on the shelf, most are DCO (Side Draft) for 12a 13B's.

We have had these independantly dyno'ed so if you would like a copy just call our office and they can fax you the comparision sheets. BTW we also manufacture cast manifolds for the 12a, 13b & 20b in Supercharged applications

Westfield SEiW. Based loosely on the Lotus 7. About 1200lbs. Has a 13B 4-port (origin unknown, suspect REPU). 140RWHP before new inlet and rebuild.



Goes like a greased rat.