AlexG13B

iTrader: (7)

i was wondering what you guys thought of it. i wanna use s4 t2 intake irons, manifolds and use s5 na rotating assembly but run it with a turbo.
im gonna be using stock s4 turbo for now but may go with a hybrid later on.

i wanna run: koyo rad
walbro fuel pump
haltech e6k
550/(what size secondaries?)
not sure on apex seals (RA SUPER SEALS?)
Devils own alky injection
stock tmic
NO AC
trailing spark plugs all around?!
also i might go half bridge

would it be safe to drive around in or will it be a ticking time bomb? ive heard a few guys run 6 port turbos and some seem to make it. i just dont wanna be part of the other few who didnt :p

what suggestions do you have? thanx.

hypntyz7

IT can be done, but given the difficulty that most people have holding modded turbo rotaries together with low compression, I don't see any need to complicate the puzzle by raising compression on top of everything else. Just run standard FC/FD 9.0 rotors and 3mm seals and you will be fine.

Hyper4mance2k

iTrader: (40)

it'd have great power potential, but with 9.7 comp ratio you'd better have a damn good tuner.

2Lucky2tha7

iTrader: (3)

lol, why 3mm? If his goal was over 40 psi, then I might agree......
And the tuning aspect of this setup is not that hard. I've already done it a few times and all you really need to do is run more conservative timing under boost, try and keep the IAT's as cool as you can (large fmic), and I personally suggest RA seals (or PTS or SCR seals if you got the money)
IF, this scenario included stock 3-piece seals, well then I'd ask why.

teddyrx2

iTrader: (33)

your going need some larger fuel injectors...e6k is a tricky computer system...so if you don't know what your doing and you got money to blow on a tuner and dyno then i say don't run that...Run the mega squirt...very good system and has been proven time and time again...and much easier to tune...RA Seal, thats he/she own prefrence...i would go with stock seals...and if you can avoid it and it's in your budget go with a front mount set up on the intercooler...do things right the first time...walbro fuel pumps are good but hey spend the money and get something like an aeromotive pump if it's funds if not then run the walbro...half bridge???are your ready for that...lots of tunning...lots of money and going turbo bridge may not make a very good daily driver...maybe for track car if anything...

manslayerx9

well the 3mm seals for a little more tuning leeway(read mistakes) and the ra's might be better on a experimental motor like this. cause if he does detonate bad they wont shatter like the stock ones and leave him needing a new rotor and housing

hypntyz7

Yeah, they'll just chew up BOTH rotorhousings in 10-20k.

Derek King

iTrader: (2)

i have been running s5 na rotating assembly at 10psi all season in my track car on stock ecu with 550s and 680s with no problems

AlexG13B

iTrader: (7)

what seals you using derek?

TweakGames

iTrader: (3)

haha you guys think apex seals are magic or something! O.o



haha running high comp turbo isn't anything super special! Everything works exactly the same, except ...well you just have slightly higher compression. You will just require a slightly different tune. Technically you will be able to make more power, with less boost.

Apex seals / engines making 200 hp with low compression high boost, is seeing the same forces as a 200 hp with high compression, low boost. (yes I know there are a lot of other variables (efficiency of turbo blah blah, but nothing major.)

This is nothing special, you will just need to be slightly more careful with boost, and tuning.

/end

hypntyz7

I suggest you go google "boost vs compression" and similar and spend a lot of time reading.

For a stock or near stock boost (under 12psi) application the higher compression is fine, and even desireable. However, it obviously requires use of the best pump gas you can obtain at all times. Whereas with, say a stock s4 turbo low compression setup, you can run 87 gas up to about 7-8psi of boost.

I have built both such setups and honestly the higher compression doesnt really aid spool time significantly or give you a lot of low end grunt...the engine remains true to it's form, which is a torqueless rotary engine, below 3k rpm. I could build one of each setup, otherwise identical except for the CR, and the average person would not be able to tell which was which.

2Lucky2tha7

iTrader: (3)

Huh??
I hope you're not referring to the RA seals, because if you are, that doesn't make any sense......
I had my block back apart at 29,000 miles on the RA seals and my housings were fine. I now have 36,00 miles on them and I still have no problem. What kind of seals are you talking about?

2Lucky2tha7

iTrader: (3)

I'm curious:
What kind of setups did you have?
was the high comp setup a stock 6-port NA block with the NA diffusers still in them, or was it more of a streetported 4-port with turbo diffusers (aka:high comp. rotors in a turbo block) The reason I ask is because putting a turbo on a block with the NA diffusers in it makes for crappy boost response. I put together a streetported RE with TII diffusers and 9.7 rotors and the boost response and low end torque and mid-range was ridiculous.

BTW xboxthug13b, remember what I told you. Since you will be using the s4 irons, your rear iron will only be able to handle 350 - 400 hp at the flywheel, (about 350 rwhp max), or else that rear iron is gonna crack. A half-bridge is entirely unnecessary and will most likely be wayy more undesirable than a decent streetport. I personally think that you won't be as happy with it as you would a large streetport.

hypntyz7

Yes, the RA seals, circa 2003-2006. I dont know about the newer "super" whatever seals, or the different color ones. I built a few engines with the older ones, and took apart several that had them, and you can always tell because they look like you had sandpaper on the apex tips. The engines still run but they generate incredibly weak compression after 15-25k miles because of the wear on the sealing surface.

I'm surprised this is the first you've heard of it...there is/was a whole multi page thread about it, with pics from several different members to back it up, in the rotary performance section.

hypntyz7

I have built a t2 with GSLSE rotors, a stock t2 with s4 NA rotors, a stock FD with 9.7 rotors, and a gt35r FD with 9.7 rotors. All of them ran well but none of them had boost response much above "normal". I think a lot of the comparison that people make, is between their tired, weak turbo (low-comp) engine, and their new, fresh, well sealing (static compression), engine that was built with high compression rotors. Of course there will be a big difference in before and after...but not necessarily due to the rotor compression.

The only thing I noticed was that above 12psi you had to be very careful not to get detonation on a hot day, and the mpg was maybe 1-2 better on the highway. Otherwise they drove identical.

2Lucky2tha7

iTrader: (3)

Oh, I didn't know you were talking about the seals from back then. Yeah, they were terrible and were to be HIGHLY avoided, lol. I built one before with seals from around 03' and it sucked!! It had every problem talked about. I used the newer batch of seals which I got sometime in 05 (?) and I never had a problem with them.
Yeah, the old ones killed housings and had all sorts of problems. The "newer" ones addressed all the problems that the old ones had.
Well then, to each his own I guess.
I personally like using high compression rotors in most circumstances.

hypntyz7

I guess in my mind it depends on the maximum use it will see. IF it is stock or lightly modded, then fine, there would not be much of a downside except the requirement of premium gas whereas before you could have usually gotten by without it.

But there comes a point of negative returns where the high compression would start to hurt more than help...after you cross 12-13psi without more advanced safeguards (big FMIC that hurts engine cooling, meth injection that is expensive) you greatly increase the danger to the engine.

2Lucky2tha7

iTrader: (3)

Just something to read, that's all
https://www.rx7club.com/single-turbo-faq-122/how-many-run-no-split-timing-325400/

NZConvertible

A 1-2mpg improvement is huge. My car was averaging 14.5mpg, so 1-2mpg would be a 7-14% increase. That's the kind of improvement car manufacturers spend a lot of time and money trying to achieve.

AlexG13B

iTrader: (7)

well gas wont be bothering me cuz in my stock t2 i ALWAYS used 93 no mater what. im always going to be using a water injection kit as a safety not dependen. fmic might be something i should look into though i guess if going with high compression.

Derek King

iTrader: (2)

all stock used seals lol

AlexG13B

iTrader: (7)

did aroncake use high compression rotors in project tina?

Aaron Cake

iTrader: (1)

The entire engine block is S4 NA.

But I'm of the opinion that the S5 NA rotors have too high of a compression ratio to make them reliable under a reasonable amount of boost.

rotarydriver108

iTrader: (16)

s4 NA- 9.4
s5 NA- 9.7 ?

2Lucky2tha7

iTrader: (3)

yes