Tuning/timing issues with turbo RX-8 please help me!!!
11-11-09, 05:03 PM
#26
That's why I came here...cause here you guys have say 30+ years of experience and there is rx7's putting down insane power. There isn't any of that in the rx8 side.
While the factory Rx-8 PCM is very modern and very advanced compared to most of the stuff we deal with around here, despite its sophistication it's simply not designed for boost. Reflashing the factory Rx-8 PCM is not reprogramming an ECU on an STi (using Cobb Accessport etc), which already has a MAF scaled for boost and other things you would expect from a factory turbo car. So when it comes to making big power, it's an uphill climb for the Rx-8--not necessarily because the engine longblock has insurmountable flaws, but because it is a MAF based OBD II vehicle that's not built for boost.
Getting back to the knowledge gap between Rx-7 and Rx-8 owners: The Rx-8 is a newer platform, and the majority of people who buy Rx-8's are not hardcore sportscar enthusiasts with multiple project cars under their belt.
11-11-09, 06:15 PM
#27
Yeah that's the biggest thing I hate about the site.... Is when you ask a question you always get do research but there is so much bull **** that's not right...how is a person that doesn't know suppose to filter that ****? Just like I wrote on there site that I had the rx7 apex seals and someone said why didn't you go 3mm if you cut the grooves. No one questioned him why he asked about the 3mm seals. I basically said they was only good for a race engine that will get rebuilt on a regular. I've read a lot of people say they are the greatest thing..but then cam at pettit and banzia both say they aren't all that and don't like using them. That's why I came here...cause here you guys have say 30+ years of experience and there is rx7's putting down insane power. There isn't any of that in the rx8 side.
thewird
11-11-09, 06:25 PM
#28
Hook it up then. You might learn something. I just don't want you to automatically freak out about detonation.
The thing you will notice about the rx8 forums (I post on there sometimes) is that some people know a lot about the factory ECU and bolt on turbo applications, but when you go to a standalone it's just a completely different deal (MAP based timing etc). There's not a whole lot of experience with it. On the other hand, you couldn't ask the typical FD or FC turbo owner about the way load is calculated on a modern MAF based OBD II car, or how cooling fan hysteresis tables work, or how fuel trims affect tuning over the long term.
While the factory Rx-8 PCM is very modern and very advanced compared to most of the stuff we deal with around here, despite its sophistication it's simply not designed for boost. Reflashing the factory Rx-8 PCM is not reprogramming an ECU on an STi (using Cobb Accessport etc), which already has a MAF scaled for boost and other things you would expect from a factory turbo car. So when it comes to making big power, it's an uphill climb for the Rx-8--not necessarily because the engine longblock has insurmountable flaws, but because it is a MAF based OBD II vehicle that's not built for boost.
Getting back to the knowledge gap between Rx-7 and Rx-8 owners: The Rx-8 is a newer platform, and the majority of people who buy Rx-8's are not hardcore sportscar enthusiasts with multiple project cars under their belt.
The thing you will notice about the rx8 forums (I post on there sometimes) is that some people know a lot about the factory ECU and bolt on turbo applications, but when you go to a standalone it's just a completely different deal (MAP based timing etc). There's not a whole lot of experience with it. On the other hand, you couldn't ask the typical FD or FC turbo owner about the way load is calculated on a modern MAF based OBD II car, or how cooling fan hysteresis tables work, or how fuel trims affect tuning over the long term.
While the factory Rx-8 PCM is very modern and very advanced compared to most of the stuff we deal with around here, despite its sophistication it's simply not designed for boost. Reflashing the factory Rx-8 PCM is not reprogramming an ECU on an STi (using Cobb Accessport etc), which already has a MAF scaled for boost and other things you would expect from a factory turbo car. So when it comes to making big power, it's an uphill climb for the Rx-8--not necessarily because the engine longblock has insurmountable flaws, but because it is a MAF based OBD II vehicle that's not built for boost.
Getting back to the knowledge gap between Rx-7 and Rx-8 owners: The Rx-8 is a newer platform, and the majority of people who buy Rx-8's are not hardcore sportscar enthusiasts with multiple project cars under their belt.
thewird
11-12-09, 08:35 AM
#29
Full Member
Thread Starter
Join Date: Nov 2009
Location: Terre Haute, Indiana
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
thank you guys so much... See I feel my stand alone is so much better then that flash crap. I understand those guys saying the factory adjust and stuff so there for it in a way is better..but that's just cause it's easier to set up and tune with. But in the long run doesn't mean it's better...
How many cars today knock or miss do to a bad sensor read or electrical problem?
With the standalone it's either on the money or off. That's what I love about it.
So you guys are saying I was way to far retarded...see what's what happens with everyone not knowing what they are talking about...so yeah I got to thinking about it.. I bet the flame was still there as it was leaving the engine creating extreme heat in the exhaust.... WHICH explains my turbo manifold cracking and toasting it's self.
I didn't open the engine before sending it off but the exhaust ports from the outside looked really good actually... I was afraid it had to do with heat and back pressure so I was looking at them.
How many cars today knock or miss do to a bad sensor read or electrical problem?
With the standalone it's either on the money or off. That's what I love about it.
So you guys are saying I was way to far retarded...see what's what happens with everyone not knowing what they are talking about...so yeah I got to thinking about it.. I bet the flame was still there as it was leaving the engine creating extreme heat in the exhaust.... WHICH explains my turbo manifold cracking and toasting it's self.
I didn't open the engine before sending it off but the exhaust ports from the outside looked really good actually... I was afraid it had to do with heat and back pressure so I was looking at them.
11-12-09, 12:59 PM
#30
Full Member
Thread Starter
Join Date: Nov 2009
Location: Terre Haute, Indiana
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
alright guys...so I talked to cam at pettit. What he's doing right now is cutting a rx8 rotor for 3mm seals...a junk rotor
He'll then cut it into to see what kinda material is left and see what type of problems...if any you'll run into.
So that's route 1
Now the thing I'm pretty sure we are going to do.. Is 13b low compression rotors in my renesis!!! and the ALS seals.
Now give me input on that!!! lol which of the two would you guys recommend?? Oh and what does a meth inj. cost to buy? I wouldn't even know where to start or what kit to get or anything.... I'd need someone to just say you'd need this one. lol
I do wiring and fab work all the time so that's not a problem. Thanks again guys
He'll then cut it into to see what kinda material is left and see what type of problems...if any you'll run into.
So that's route 1
Now the thing I'm pretty sure we are going to do.. Is 13b low compression rotors in my renesis!!! and the ALS seals.
Now give me input on that!!! lol which of the two would you guys recommend?? Oh and what does a meth inj. cost to buy? I wouldn't even know where to start or what kit to get or anything.... I'd need someone to just say you'd need this one. lol
I do wiring and fab work all the time so that's not a problem. Thanks again guys
11-15-09, 03:10 PM
#33
No, you cannot use the earlier lower compression rotors in the RX-8 motor.
The problem is they moved where the side seals meet the corner seals so they could have an earlier opening port.
You put the older rotors in and the leading edge of the perpendicular (lower) side seal will fall in the port on port closing and break off.
At least this is how I understand it- haven't had the RX-8 parts in my hands to confirm this yet.
Old rotor- see how side seals meet corner seals in middle of corner seal.
RX-8 rotors- see how side seals meet corner seals above middle of corner seal.
The problem is they moved where the side seals meet the corner seals so they could have an earlier opening port.
You put the older rotors in and the leading edge of the perpendicular (lower) side seal will fall in the port on port closing and break off.
At least this is how I understand it- haven't had the RX-8 parts in my hands to confirm this yet.
Old rotor- see how side seals meet corner seals in middle of corner seal.
RX-8 rotors- see how side seals meet corner seals above middle of corner seal.
11-16-09, 04:18 PM
#35
Full Member
Thread Starter
Join Date: Nov 2009
Location: Terre Haute, Indiana
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
well from what cam told me the rx8 has to oil rings and then a compression ring..and the rx7 just has two oil rings. So he said he was going to machine the third ring. Said he had done it before in another engine and that that engine actually gained some power on the top end.
11-16-09, 04:26 PM
#36
Full Member
Thread Starter
Join Date: Nov 2009
Location: Terre Haute, Indiana
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
Yeah I know when not in boost I'll lose some power. But all in all I figured the rx7 rotor's was by far a smarter move. Besides when I boost 10psi on the rx8 rotors and 10 on the rx7 I'll get more power on the rx7 correct...for there is more area to compress the air...which means more fuel as well. I can't remember exactly what turbo I have but it's like a gt35/40 and I dont' have a clue what my hot and cold and trim and all of that is. I just know I start to spool around 3300 and hit full boost usually by 4000 and it holds the 14 psi with no problems...it's smooth with no creep or it's either there or not. Takes a second to spool so I guess it's what people call laggy cause you either feel it or you don't. Even on half throttle take offs you'll feel it kick in. In first when my turbo spools it hits so hard I loose all traction and in second it does the same for a few seconds.
11-17-09, 07:44 AM
#38
Full Member
Thread Starter
Join Date: Nov 2009
Location: Terre Haute, Indiana
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
I'm going to call cam today and talk to him about all of this and see what he says about all of it. I'll bring up the side seal issue and see if he says it is or isn't a issue. Last I knew he said when he got done doing the work he was going to send me pictures to look at..so maybe he'll be close enough to send me some pictures so I can post them.
10-05-11, 03:16 PM
#40
Junior Member
Join Date: Sep 2005
Location: new zealand
Posts: 38
Likes: 0
Received 0 Likes
on
0 Posts
Turbo rx8
I'm just going to jumb in here -- been awhile since I was on this site, came back via a google search.
In the above posts -- someone state that theres -- basicly alot of BS on RX8.com -- I think thats being polite.
Anyway -- I've done a back yard turbo (cheap as chips) Rx8, Dynoed at 280whp on 9 psi -- and running on about the same as your 91 gas (not a good thing, but thats all I can get where I live)
below is a dyno of a std jdm 6 port, and my 8's dyno.
just throwing this out there, as I'm thinking I'll get more help here ??
In the above posts -- someone state that theres -- basicly alot of BS on RX8.com -- I think thats being polite.
Anyway -- I've done a back yard turbo (cheap as chips) Rx8, Dynoed at 280whp on 9 psi -- and running on about the same as your 91 gas (not a good thing, but thats all I can get where I live)
below is a dyno of a std jdm 6 port, and my 8's dyno.
just throwing this out there, as I'm thinking I'll get more help here ??
10-05-11, 04:20 PM
#42
Junior Member
Join Date: Sep 2005
Location: new zealand
Posts: 38
Likes: 0
Received 0 Likes
on
0 Posts
10-05-11, 10:06 PM
#43
We'll see how long the side seal springs can stand up to those hot exhaust gases. Do you have a pic of your turbo manifold? Is it a long or short runner? I would expect a shorter manifold to cause more heat buildup near the exhaust port and thus more stress on the side seals and side seal springs.
10-06-11, 01:19 AM
#44
Junior Member
Join Date: Sep 2005
Location: new zealand
Posts: 38
Likes: 0
Received 0 Likes
on
0 Posts
Turbo 8
We'll see how long the side seal springs can stand up to those hot exhaust gases. Do you have a pic of your turbo manifold? Is it a long or short runner? I would expect a shorter manifold to cause more heat buildup near the exhaust port and thus more stress on the side seals and side seal springs.
Turbo is remote -- basicly -- where the Cat whould have been, Like I said -- cheap back yard set up.
It does me, (its cost less than a 5th of what I was Quoted to bring in a standard Greddy kit)
But I would like to Iron out a few of the -- Kinks, so to speek out of the system.
I do agree with the post about the re-flashing being -- not the right thing to do ?? -- I'm even worst off -- Cobb AP, will not work on my 8 (its one of the first built) so I've been using Hymee Pro=Tuner -- which is OK, I was one of the first beta testers -- but it was never fully finished !! -- A lot of Unknowns.
10-06-11, 03:29 AM
#45
Junior Member
Join Date: Sep 2005
Location: new zealand
Posts: 38
Likes: 0
Received 0 Likes
on
0 Posts
Thread
Thread Starter
Forum
Replies
Last Post
Frisky Arab
2nd Generation Specific (1986-1992)
13
08-18-15 05:30 PM
