Hello everyone lol so I know your work is with the rx7 and I'm on the 7 site. It just seems people don't know what they are doing with the 8's. My first engine went after 40k with about 5k of boost at 10psi. The second motor which is covered only made it like 3k and I had it built and tuned at pettit racing. I climb into boost at like 13's and by 5psi I drop down between 10.9 and 11.1 afr. I thought it was my timing that's why I had them tune it. Now I'm lost so I'm going to people who have experience...people who are putting out real power on a 13b. Just wondering if you could tell me what my split should look like and where my timing should be from idle up. Last I was wondering are you running the ALS seals...is that what you recommend.

My rx8 rotors are machined to hold the rx7 seal
I do premix
drive it easy till warmed up
and it's never seen the track since the turbo
Microtech ECU

oh and since tuning is so important...is there a way to wire the knock sensor the the microtech so you could see what it's reading..or is there a way... Does the knock sensor just send a ground single like a temp sensor?

 

We need to know more details. Like the break in period, how the motors blew, type of fuel your using etc. CJ

 

^ what he said. How are the motors going is important.

On a side note, turbo RX-8 in Terre Haute? You need to bring it to indy when its back up.

 

Take screenshots of your Microtech timing maps

 

also, about the knock sensor:



it's not as simple as logging a temperature sensor

 

Probably you're timing maps, you have to retard those Rx8s a lot in boost...

What turbo are you running? Every Rx8 owner should invest in water/methanol if running pump gas...

 

I run 93 octane. The first motor had 40k on it before the turbo and only lasted 5k. It just slowly went down hill running the 10psi of boost. Started with noticing a idle that was kinda ruff to a idle that bounced to pretty much no idle lol. The second motor was built in florida. Cam built it and installed it. I drover around 400 miles before we tuned it to 8 psi. I drove it home and then continued the tuning and tuned it to 14psi. By that point the motor had around 1700 miles on it. I've been driving like this for 7 months and all of a sudden I'm using a lot of oil and cam tells me to look for a oil leak and I tell him there isn't no leak so he says take it for a drive does it run right. It ran right idle'd smooth no real problems. But the more I drove it the more oil it used and the idle got to the point it wouldn't idle. I called him and he said pull it he'd rebuild it. But anyways I had to keep driving it for one last day of work. That day it wouldn't idle but everything else had been fine. So I got on it in first coming down my road everything was fine. I hit second and I got a surge of power I over boosted to 17psi. Would of could a oil seal do that? But needless to say I either blew a apex or that oil seal is gone. Cause I lost compression when that happened. He's got the motor. He's redoing it for free. But I could change the seals that's why I was asking about the ALS cause I want a seal that's going to hold up. I want to be able to boost and not worry about it.

As far as over boosting... I've boosted to 16 before a few times when I was tuning it last which was like 7 months ago but this oil issue is like in the last 2 weeks. I know my AFR is good even at the 18. If anything it's too rich. I was around 10.5 at 16psi so I know it's rich cause it cares the same high curve all the way to 20.

 

So how much boost are you running? 16, 18 psi? On pump gas?

 

But like it says the voltage goes up. So it works just like a temp sensor. As the car gets hotter it sends a better ground or more voltage. a knock sensor does the same. So in theory I should be able to put that knock sensor as my temp sensor. so I could log it. Sure my numbers would be way off but I'd be able to see my detonation.

Right? I'm thinking about this in the right way..correct?

 

I wouldn't arbitrarily call RX-8 people dumb. You aren't asking the right questions or giving the correct information. There are PLENTY of dumb RX-7 people too!!! I can point to any number of current threads right now as proof and they never end. Both groups have some intelligent people too.

First off if you are running a Greddy turbo, throw that piece of tiny junk away. It sucks and there is absolutely no way possible to make it acceptable enough to justify installing it anywhere other than a trash can. That's where all Greddy products should be though. If you have ANY other turbo kit, you're off to a good start. The rest of your setup seems fine although the Microtech leaves alot to be desired.

The problem is that you seem to be asking for a map. First off that isn't going to happen. Any map advice that gives you direct numbers will be suspect as they clearly have no idea what they are saying. We can only give you advice that points you in a certain direction. No one can give you a safe timing map and no one can claim that any a/f ratio is "safe". These are just too general. There are also different philosophies on tuning and when it comes to rotaries there is no one way. It all has to do with how split is dealt with.

You have high compression. That is one issue and pretty much the main one. In general to be safe you'll want to run a wider split and back the timing off with boost. How much is dependent on your setup as an engine with high compression and 1 turbo may not have a map anywhere near the same as another engine with lower compression, a different turbo, but the exact same boost level. Pettit definitely has plenty of experience so there is no reason to think anyone here is going to give you better advice. People also have their own opinions of Pettit though but experience can't be denied. They also have a racing history.

You really just need to find a rotary tuner you can trust. They are out there. I'm not sure who is in your part of the country though. I can think of many in the south.

 

go to japtrix. i believe they are still in riveria beach. not too far from pettit. talk to jack or rodger. jack is the tuner, rodger is the owner. great guys up there.

 

besides sample rate issues, you would have a very tough time interpreting what you are seeing. Temperature sensors (thermistors) have a linear signal function. Knock sensors have a sinusoidal signal function, and interpretation of that signal is based on both the frequency recorded and some set of filtering logic. What that means is that there's more to it than just how high the voltage may be... it also involves knowing when the voltages are generated (filtering logic), and measuring how close they are together (frequency) in a given time interval.





Buy an aftermarket knock sensor system or get an EMS that can directly interpret a knock signal.

 

What kind of timing are you running? Considering the boost your running with the compression ratio are you really surprised your having problems. Most people limit turbo motors to 16 psi or so with 9:1 ratio rotors. Your running 10:1 and have hit 16 psi and run 14 psi on a regular basis. I would say you should get an EGT gauge as well as water injection before you go any further. I can't image the ports on the renesis flowing well enough to not cause sky high egt's.

 

I wrote it but didn't really mean rx8 people are dumb.. I just knew I'd get a lot of hits with that title and it's not really I don't trust pettit...But it's kinda hard for cam to do my tune and really do it well. My ignition timing was done sitting in the car off of the top of his head. and the tune up to 8psi was done doing a few pulls in my 8 on the road. Everything was tuned really rich for the break in. Hell I got like 18 mile to the gallon with 3.9 gears on the way home now I get like 22 or better. As far as maps I'm looking for someone to basically say this ignition map would work cause they have experience and know it would work. I'm not looking for one that will produce the most power but one that's a reliable one. As far as tuners there is banzia and last time I talked to them was about building my engine and they told me if it was turbo'd they wouldn't touch it wouldn't even rebuild it without a warranty. So I never called back. I have the mazsport type 3 turbo and have upgraded many things on this kit. As far as split I think mines between 12 and 15 let me get the net up on my other cpu and I'll post the maps.

As far as doing meth inj. would that be set up kinda like say once I hit 5psi of boost it would kick in?

 

here are my maps.. so my split is farther then I thought. and I run in the - more then anything. so if you'd do the math this is what I got...make it easy for everyone.

6 boost

3000 3500 4000 4500 5000 5500 6000 6500 7000 8000 9000

12 11 9 7 6 6 6 8 10 12 12


10psi


3000 3500 4000 4500 5000 5500 6000 6500 7000 8000 9000

6 5 3 1 -01 -01 -01 01 03 04 04

14psi

3000 3500 4000 4500 5000 5500 6000 6500 7000 8000 9000

3 2 0 -2 -4 -4 -4 -2 0 1 1

18psi

3000 3500 4000 4500 5000 5500 6000 6500 7000 8000 9000

-1 -2 -4 -6 -8 -8 -8 -6 -4 -3 -3

like someone said you have to retard the hell outta it. I think I am aren't I compaired to a rx7

oh and with this ignition timing I was putting down 305 at 8psi with a bad tune...running so rich is was bogging out I had the 305 at like 5000 rpm and lost power when I hit 6000 due to...to much fuel. If I had to take a guess I'd say I'm putting around 450 at the wheels. My act extreme pressure plate and 6 puck disc looks like it's been slipping!!!! it's only like 2 months old!!!

 

arghx now I know you say it's more then all that.. so are you saying if ran a wire from my microtech to the knock sensor...insulated and everything of course that it wouldn't read anything?? Cause actually if I was logging it I should be able to see at this rpm and load it jumped... I might be wrong I always do trial and error with things like this. I think it's worth a shot. hell I'm going to play with it tonight I'll use my oil temp gauge in my car. it won't be insulated but I'll hook a solid ground to the sensor and see if hitting it makes it jump

 

You're timing is too far retarded, maybe that is your problem? I also seriously doubt you are anything past 300rwhp with timing levels and your afr numbers regardless of what turbo you have. What is a mazsport type 3 turbo anyhow? I usually run 5 degrees less timing than standard Rx-7 timing maps.

 

it's your car, do what you want. You'll probably get some kind of reading, but what are you going to do with it? I don't think you realize how hard it can be to interpret even actual OEM knock sensor readings that are already filtered by the ECU. I am talking about on Rx-7's (through Power FC) but also datalogging Subarus factory ECU's(which have a very aggressive knock control strategy), 3000GT's ECU's, etc. Just because the overall voltage range "jumped" doesn't mean you are necessarily knocking. Sometimes it does, sometimes it doesn't.

Also, didn't Mazsport go out of business? I thought their turbos were modified Greddy's?

As for the timing... well it's easy for someone to say "oh it's too retarded, you blew your motor from that." I dunno, maybe. How can you prove that? Oh and what was the split again? I would do 12 or 15. Otherwise we don't know much about the car... Just looking at the timing, you were running at 6psi what I probably would've run at 10. And at 14psi, I would've run your original 10psi numbers but added maybe three degrees to it. But did that timing blow your motor? It's hard to say. Was it an apex seal you lost, or a side seal? I can see some high EGT's (from really retarded timing) eating a side seal on a side port motor.

 

Just to let you know.

On a turbo Rx-8 that I worked on which had the Mazsport kit the original manifold was 100% poop. Basically the flange was a cut sheet with the holes having being cut by a plasma cutter looked as if a 2 years old had done it.

When the kit was taken apart the disappointments were:

#1 the manifold design
#2 the turbo looks like a To4e super small hotside

Also, working with the Microtech is a Pita I hate those graph based everythings.

 

Yeah they went outta business. Some of the kids were nice and some weren't depends on if you got one from the beginning or the end. My manifold is straight and well cut and fits nicely. But like what was said I didn't think it looked 321 or 304 for the flange on the motor..it has pours. So yeah my timing like a said was very retarded. My guess is a side seal cause I was starting to use oil and I mean a lot of oil so I thought it was a side seal. But then I had the boost peak and I figured I blew a apex but I guess if I blew a side seal I'd lose compression too.

 

oh and arghx I played a little with the sensor tonight and it would work that way but it did seem rather jumpy. It was just a thought and I like to tinker and think. hell keeps me busy and keeps me from buying stuff that I don't need.

 

A question how's your porting in the renesis engine? The renesis sideseals are thinner then the older 13b engines. And are not realy reliable at boost. My engine builder says that they suck for turbo charging a renesis engine. They do not hold the boost back. If you run like 6 psi they might hold up for a while. But the sideseals are the weakest link on a renesis engine.

Why don't you just put in a 13b-rew engine instead. Since you are already running a standalone ECU. It would save you so much headache.

JT

 

Well what temperature plugs are you running, and any type of upgrades to the fuel system?

It also seems to me that you're running to much boost for pump gas. Even with lower compression rotors in a FD, I only run 15psi. I know there are guys out there who run more boost on pump than me, but I think 15psi is the safe limit.

 

I tuned an RX-8 with the Microtech running 12 PSi and to this day it is running. I created a little ignition timing calculator so you can better visualize what the timing actually is with your settings. This was the timing I used for that RX-8.



I was never happy with the way the Microtech handled the injector transition though... The turbo kit was the Esmeril Racing one and I agree the manifold design was disgusting at best.

Also, I agree your timing is waaay too retarded.

I also found the same problem on the rx8club site. A lot of the bigger members really don't know what they are talking about. Obviously theres exceptions but I find it much worse over then over here. And when you tell them they are wrong, they get all pissy about it. A lot of their knowledge is based on hearsay or "well it works for me or my friend" and if you tell them otherwise, they don't care.

thewird

 

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.