NA Bolt on's
 

So i have taken out my turbo engine to make some more or less big changes, at this will take lots and lots of time and money. So i bought a NA engine, so i can have my FC on the road while i build the turbo engine.
But 155hp, that is just to damn little, wich bolt on mods give the most bang for buck?

I already have:
2*2.5" SS exhaust, with very little backpressure/restriction to the airflow.

I will buy/build:
true dual rotary works 2.25" header.
CAI

And where do i go from there? is there any more easy/ low cost stuff i can do, wich doesn't hurt reliability or cause much downtime?

you're on the right track with the exhaust, every improvement there is noticeable.

the ECU/ tuning is the other biggie. the stock map is ok, but but you can have a much broader power band if you can tune the fuel and ignition

I'm going to go standalone on the turbo engine, so i could always try it out on the NA engine first. Most likely going to buy Haltech sprint RE.

i don't know what that does to your time table, but yeah learning the new ecu on an NA engine is a lot more fun.

BTW the family trip this year included norway, its beautiful.

advance the timing 3-4 degrees, tb mob, port the tb, and a cold air box mod or something. i significantly felt the difference from removing the rubber moldings on the hood so air could go in through the head lights when its in the sleepy eye position. having the aux ports lubed up also makes the car more responsive. have fun with the throttle response of the n/a while you can cause i did ha. oh yeah you will be surprised how quick your throttle response will be after cleaning out the intake manifolds with de greaser and a brush. so much carbon in these 20 year old cars.

this sounds like the dumbest ricer mod ever, but the intake temps do drop with the headlights up....

lol yes

So a CAI box with a feed hose from the front should do the trick then?

And how do i advance timing, by turning the CAS?

HA! hey whatever works man even if its temporary. theres about a half inch gap between the headlight housing and hood which is enough to get the cold air in.

you would have better luck propping up the hing side so it vents over the windshield as the air passes through the engine bay.

i know! it sounds like it would never work, but actually it does.

What ecu would you recommend that would work with an NA and a TII swap?

n/a haltech
t2 rtek

What does it take to convert my T2 engine to NA?

And i don't just mean changing out the sensors, but getting high comp rotors and so on. Wich rotors are the best for a NA setup?

Basicly a parts list of whats needed.


Considering ditching the turbo all together :)

I'll trade you my motor for yours! :egrin:

lol, ok if you pay for shipping :P

And now I realize you're in norway lol.

Just sold the T2 longblock(without the turbo) + an na gearbox that need's overhauling for 1000usd :)

So now it's decided, instead of just going na while i finish the turbo engine, i will go the NA route all the way.

So i wan't more than 200whp.

My plan do make this happen:

S5 roating assembly, get it balanced so i can run higher rpm's (want to be able to run 10k redline or more??)
Bridgeport
true dual header and dual exhaust, SS all the way.(already got it)
Haltech sprint RE
tweakit ITB's(or build a itb setup myself)
upgraded spark? (is it needed, and what should i get)

looks good. the limit to the stock ignition is since it fires TWICE each revolution charge time gets too small to charge the coils 100% over like 6000rpm. the cheap solution, is just to run 2 leading coils and have it run sequential ignition, it fires half as often, and thus doubles the charge time. the haltech should be able to do it.

an MSD box would work too.

I think those setups use two *trailing* ignitions, since those fire independantly.
I like lightened flywheels on NA's. You don't gain hp, but it gives the illusion of torque. You'll need the lightened flywheel and an automatic counterweight from the same series engine.

What about LS2 coils?

+1000

For the sake of simplicity, I would try to run two leading coils from trailing signals. Each coil would be connected to leading and trailing of one chamber ie no split and charge time would be same as fully sequential system:nod: And it should be cheap:lol:

those work fine, but you have to buy them and the stock FC coils are usually free

i think the haltech can just run a direct fire setup

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..

I have a welder, a spare lim, 4 49mm tb's from my Neon, so i will start planning and then fab a itb myself.

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).

lol

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.

So i should stick with S5 rotors when?

they do work right out of the box!

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

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?

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

rx8 eccentric shaft?

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

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 :)

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

Explain.

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 won´t 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 didn´t share any realistic goals. Jumping from one idea to the other and hoping it will make some killer engine just doesn´t work.

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.

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.