RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   Naturally Aspirated Performance Forum (https://www.rx7club.com/naturally-aspirated-performance-forum-220/)
-   -   NA Bolt on's (https://www.rx7club.com/naturally-aspirated-performance-forum-220/na-bolt-ons-973034/)

j9fd3s 10-21-11 04:36 PM

1 Attachment(s)

Originally Posted by Pettersen (Post 10832679)
Money is not a big issue, and rx7 are rare in norway so finding a set of used coils for sale could be difficult. + LS2 coils would be new, not 25 years old..

good point! judging from our trip to norway+sweeden you'd have better luck using a 1960 cadillac coil, i saw more of those in 3 days in norway than i've seen the whole rest of my life, and an edsel too!

since the haltech is adjustable for dwell, you could use any coil really. you just need 2 of em.

pic is the friday car meet in bergen (i guess).

flaco 10-21-11 07:57 PM


Originally Posted by j9fd3s (Post 10824031)
this sounds like the dumbest ricer mod ever, but the intake temps do drop with the headlights up....

lol

Pettersen 10-22-11 04:29 AM

What would i need to do in order to run RX8 rotors? and how much more would they give me compared to S5 rotors?

j9fd3s 10-22-11 12:59 PM


Originally Posted by Pettersen (Post 10833503)
What would i need to do in order to run RX8 rotors? and how much more would they give me compared to S5 rotors?

you need to mill the apex seal slots deeper. Rx8 rotors are a mixed bag. so far power is lower, possibly because the combustion recess is too small.

Pettersen 10-22-11 02:03 PM

So i should stick with S5 rotors when?

j9fd3s 10-22-11 08:06 PM


Originally Posted by Pettersen (Post 10833850)
So i should stick with S5 rotors when?

they do work right out of the box!

Pettersen 10-23-11 03:54 AM

What if i have a RX8 shortblock available? Is it a better start for an NA build? and can i use FC transmission on a rx8 block.

j9fd3s 10-23-11 02:17 PM


Originally Posted by Pettersen (Post 10834418)
What if i have a RX8 shortblock available? Is it a better start for an NA build? and can i use FC transmission on a rx8 block.

well its does make more power stock VS stock. the Rx8 uses the same transmission bolt pattern as everything else post 1974, but it uses a turbo size clutch. so to use the NA clutch, you need a light flywheel

Pettersen 10-23-11 06:05 PM

I decided to be an asshole and blow of the deal on my T2 engine, as far as i can tell, the 4 port block is a better base for a bridgeport build. So i will brideport my already streetported T2 irons, and then get a S5NA rotating assembly,. And that should be it for the engine mods.

So what other parts should i upgrade on the shortblock?

Pettersen 10-29-11 05:23 PM

What should i upgrade in order to run 10-11k rpm?

LoLsmileyFC 11-03-11 10:24 PM


Originally Posted by Pettersen (Post 10842503)
What should i upgrade in order to run 10-11k rpm?

rx8 eccentric shaft?

j9fd3s 11-04-11 01:55 PM


Originally Posted by Pettersen (Post 10834945)
I decided to be an asshole and blow of the deal on my T2 engine, as far as i can tell, the 4 port block is a better base for a bridgeport build. So i will brideport my already streetported T2 irons, and then get a S5NA rotating assembly,. And that should be it for the engine mods.

So what other parts should i upgrade on the shortblock?

to go from 8500 to 9500 for the Rx8 all mazda did was use the FD bearings, they lightened the Eshaft (insignificantly), balanced the assembly better, and they used apex seals that are lighter because they are shorter. you should use carbon or ceramic seals, its also a good idea to bump the oil pressure, the FD regulator is cheap

Pettersen 11-04-11 03:52 PM

What if i want to go higher, say 10-11k?

Got impulsive and bought semi pp housings :)

Going to build some sort of sequential throttle setup, plan on having the stock ports open to 20-30% before the pp's start to open and having all tb's reach 100% at the same time, shouldn't be to difficult, just need to find a way of getting it looking nice and clean :)

rotarygod 11-04-11 04:15 PM

There is no reason to go to 10-11K rpm.

Pettersen 11-04-11 05:10 PM

Explain.

Liborek 11-04-11 06:10 PM

Unless you want to be disabled for life, there is no point.

You will have hard time to make any power at such elevated rpms. It requires tuning and making everything work as package. By the time (if) you will make some power at such rpms, it wonīt be usable and engine performance as whole will be poor. Not even taking into account engine life which gets exponentially shorter with anything over 7000 rpms.

Seriously, you asked on many forums, but you didnīt share any realistic goals. Jumping from one idea to the other and hoping it will make some killer engine just doesnīt work.

rotarygod 11-11-11 02:24 PM

Here's the thing about just arbitrarily trying to go higher in higher in rpm. This is all going to assume that you aren't going to spin a bearing, shatter a flywheel and amputate your feet or potentially kill yourself and others when the shards go flying through the floorboard, or have your rotor faces crash into the side plates from severe eccentric shaft warping which will destroy your engine. It's also assuming you have a way to tune your engine for that rpm. Anyways...

If we ignore the overwhelming odds against success and just assume none of that will happen, you are going to hit airflow and tuning issues with the intake and exhaust system. You may be thinking that you'll just run a short intake and exhaust so it gets tuned to a higher rpm. On paper this works fine. However as your power band gets higher in the rpm range, it also gets narrower. Lets say your standard engine has a max rpm of 8000 and makes good average power at full throttle from 5500-8000 rpm. This is all made up btw. That would be a nice usable power band that is 2500 rpm wide. Now lets say you have an engine that has a max rpm of 10000 and your usable power band is from 8500-10000. You can see that it got narrower and is only usable over a 1500 rpm wide range. Go up higher and it will narrow even more.

The higher your redline, the more a close gear ratio transmission becomes necessary. Since you are probably using a standard street car transmission and gear ratios you are going to find that there is no point in revving an engine to 12K when your gearbox wants to be shifted at 7K. It's a complete waste of time. You aren't getting the performance you think you are.

The only way you would EVER want to rev this high is for some special reason where you are in a race situation and the only way you can be competitive is to rev it that high. Even then it will only be limited to a few seconds at a time and you will have gone to so much time and effort, not to mention spent so much money that there would have been no point to it.

If you do decide to still pursue this anyways, when something fails take pictures. I want to put a "fail" border around it.

Pettersen 11-20-11 04:54 PM

not trying to get the engine to make all power above 9000rpm, i just want it to be able to handle high rpm in case that is where the powerband turns out to be. But i told the guy doing the semi pp that i wanted it ported so that the powerband isn't to high.


All times are GMT -5. The time now is 09:04 PM.


© 2024 MH Sub I, LLC dba Internet Brands