olddragger

iTrader: (3)

dont ignore superchargers in your quest. SC tech is advancing. Their effecientcies are improving as more and more companies are working on them. Its true that they will never be as effecient as a turbo--but does that matter at the power level you want?
I DONT want to start a turbo versus sc debate here--so yall behave yourselves.

cavemancan

I haven't...I honestly gave them fair consideration but since this build will be done by my friend and myself (most parts fabricated by him)...1) He knows turbo setups, 2) I would prefer to have more torque, 3) Price: we can make many of the parts ourselves (not including intercooler and merge collector) which makes this project much more affordable, and 4) I just can't get used to the super charger sound in a rotary (not a deciding factor though).

Another question...how do I determine injector size? I know most move the secondary's to the primary position but what should be in the secondarys now?

olddragger

iTrader: (3)

those are really good reasons to do what you are doing. Looking forward in seeing this build.
You go dude!

999miki

Most probably not. Stick with Turblown's recommendation. High efficiency of 82mm compressor with room to grow and good turbine match of stage 5 wheel.

cavemancan

Thanks guys! You all helped a ton!

Remaining questions:

- how do I determine injector size? I know most move the secondary's to the primary position but what should be in the secondarys now?

- Who makes a good recirculated blow off?

- What about the waist gate?

I would like to know how to determine what to use so I can make an informed decission.

olddragger

iTrader: (3)

different tuners like different injector capacity. Steve Kan for example likes 1000cc's per 100 hp. Others are ok with a little less. There are a lot of injector size calculators on the web. You may want to play with some of them--just to get a general idea. So many choices.
My set up some will say ---mehh--but it works ok for me. I dyno right around 300 at 9K on low boost of 7 to 8. I have oem injectors that have been cleaned and balanced in the primary and p2 positions. in the p1 position i run uncapped yellows. I have 91% of flow being used at max rpm/hp.
I would love to have the s2 primary injectors and I may get them when the price comes down a little. They are a little bigger and have a much better atomization pattern. But that means I would also have to retune.
Let me just throw something out there. Our cars are getting the miles and age on them now. I recently discovered that my alternator, after it gets really hot, was only producing 13.1 volts. Well that affects everything. I had another used alternator available and I swapped it out and at the same temps it was producing 13.4--13.6. Now i really couldnt tell any difference in how the car ran, but that little bit of voltage could really affect the fuel pump etc. So you may want to check yours before the build is complete?

Kane

iTrader: (1)

AFR makes it easy.

If you are shooting for supporting an 11.0 - 1 AFR and 350 WHP.

50 lb/min of air means 4.54 lb fuel / 80% Duty Cycle = 5.68 lb min fuel or approx 3400CC/MIN

Divide by Two Rotors, 1800CC/MIN per rotor should be ok.

cavemancan

What I've seen is the secondary's get put in the primary position and 1000cc injectors get placed in the secondary position. I think Esmeril did this with there kit. but don't we have 4 secondary's and 2 primary's? I believe this is totally wrong since I did see a different description for 2 of the 4 injectors that appear to be the secondarys...does that make sense?

I have 115,000 miles on the chasis and 15,000 miles on the motor but I assume they used all my old accessories when the replaced the engine. So the alternator more than likely is suffering from this. Remember my post about the fuel starvation issue? Well, Mazdaspeed motorsports did mention they have pulleys to "slow down" the alternator. I further assume this could be contributing to the overheating. Question is how does the pulley change affect a daily driver Rx8.

cavemancan

I know you posted the math somewhere...Is this all in the rotary math thread?




EDIT: Anyone know where I can find a blown Rx8 motor for dirt cheap? We need it for test fitment. Does not matter if the motor is salvagable. Only needed to test fit turbo system.

Brettus

iTrader: (2)

Think what you mean is P2s get put in P1 spot and larger injectors get put into P2.

stock you have :
P1 - 290cc red mounted in centre side plate
Secondaries - 380cc yellow - mounted in outer positions on lim
P2 - 380cc yellow - mounted in inner positions on lim

olddragger

iTrader: (3)

i always get the p1 and p2 mixed up. My bigger injectors are in the middle of the 4 injector rail.
Do most injector balancing companies flow test at our fuel pressures?

Brady Black

I have seen many 8s modded with turbos, and some with the Pettit SC, but I have yet to see anyone with a twin-screw SC. I have been looking to go FI for awhile now and decided to go the supercharger route. I really liked the idea of a Pettit SC, but I would prefer a positive displacement supercharger. Is this just wishful thinking? Everyone seems to go the Pettit route. Is that because a twin screw would not be worth the time/effort/$$$$$?

Brettus

iTrader: (2)

Pettit is a twin screw .......................

skc

I have the Hymee kit which is also a twin screw. So, it has been done already and it works well in the RX8

blackmike

Ok What's the best kit tc for making 300whp And setup, my start goal is 300, what do I need to achieve this pretty reliable. This is going on a drift car. I don't want flaming I just want help, email me real help if your not gonna give me crap, I believe in the renny engine mgbarbosa1225@gmail.com I have been reading and i know the search bar... Would really like help from mm but i do not know him but any good helpi really appreciate

Brettus

iTrader: (2)

Buy a used Greddy kit and upgrade it ...........

TeamRX8

iTrader: (25)

Sometimes giving someone what they want is the opposite of helping them

A 300 hp Renesis still has insufficient torque for practical drifting technique.

Brettus

iTrader: (2)

My old setup would spin the rears in second just by hitting the throttle (no clutch drop)

blackmike

plus I'm a very aggressive drifter, there was no limit to my underpowered t2

blackmike

what what I need to upgrade on the Kitkit

yomomspimp06

read the stickies and follow brett's threads. all the info is there

Posted From RX8Club.com Android App

Amyas777

Might have been Mothballs (consist primarily of naphthalene)

Dillion Phelps

So in a normal car that uses cylinders i would say a turbo is a better choice. But from what I've read(i didn't read every thing) I guess a supercharger is better(for someone who wants to race/drift)? The reason I say this is our engines can/will go to rpms.


please dont troll just explain if you disagree

Brettus

iTrader: (2)

2nd chart down .............. self explanatory (if you know how to read it )

https://www.rx8club.com/series-i-maj...7/#post3158241

AAaF

^Well, for race purpose, I'd say the throttle response that is obtainably with a SC is very important as well, not only flat torque and top power. How much difference is of course down to your turbo setup.