Alright Rxheaven, going to try something: Moving Lead advance at 15psi from 16*BTDC to 14*BTDC, at 22psi from 15*BTDC to 7*BTDC, and to 30psi (which I'll never hit) to 3*BTDC. Using 8* split. Will try it either tonight or tomorrow.

Btw, this is an 8.5:1 S5 partial bridge motor.

So you're saying these plugs will last me 50k miles plus? even if I am running 425 rwhp and 50/50 ai? hrmmm.

I just got those plugs in the mail lol. They're supposedly the same plug as the NGK r7420, just rebadged by Greddy. They're about the same cost but the Greddy ones are much easily more attainable.

thewird

Those are very similar to the "reccommended" plugs for the GTR. People say nothing but good things about them. I haven't used them yet as I've had good luck with $1.50 coppers but I'm going to try a set this year.

Can you tune on these plugs?

Or should you tune with a new set of stock plugs, and than change them out for these.

With these plugs, what heat range is recommended? 9 leading and 10 trailing? Or will 9 all around work fine.

this thread is epic.

last september i did 23 4th gear 2000-8000+ dyno runs running my FJO HD AI. given the thread is currently focused on tuning i thought i would pass on some of my metrics.

RPM*K----------------6---------6.4----------6.8--------7.2---------------7.6---------8



F IAT after IC
before alcohol------95--------94------------94----------94--------------94---------94

F water temp-------185------------------------------------------------------------------

tps--------------------100%-----------------------------------------------------------------

boost-----------------19.5------20.9--------21.1----------21-------------20.5------19.8

fuel press------------57.8------59.6--------59.8----------61.5----------53.4---------61.2

injector duty
cycle-------------------57.3-------63.5-------69.3----------73.6--------73.7----------73.3

knock-------------------22.5------4.0----------7.0-----------15.0--------13.5----------6.3

IGL----------------------12.5-------12-----------13.5---------14.5---------15----------15.3

IGT-----------------------1.5---------1-----------2.5------------3.5---------4-------------4.3

AFR----------------------11.5------11.8---------11.7----------11.9------11.1----------11.3

pre turbo
EGT----------------------1532------1553------1577-------1574---------1532--------1551

EMP PSI
(exhaust manifold
backpressure)-----------20----------10---------23-----------23-----------24------------26


the run (#23) was the last of the session... 498 rwhp SAE.

i thought it would be interesting to share the above as the thread is currently focusing on EGTs and of course i am running a fairly similar amount of meth as Brian.... actually a touch more.

note my EGTs are stable at 1550 at 20 psi.

my EMP is the reason. 23 psi backpressure at 20 psi boost.

my 2 rotor drives two Stage Five turbine wheels w two 3 inch downpipes.

when comparing turbos i take the inducer and exducers and solve for their area, add them together and divide by 2.

hotside area:

GT35R 5.17 sq inches
P trim 5.89
Q trim 6.65
GT42 87 mm 7.95
my two Stage Fives 10.81

add the hotside discharge area to 13 sq inches of DP:
http://img220.imageshack.us/img220/8376/002vn1.jpg

and you probably have the answer re backpressure.

i do believe at some point, even w perfect tuning, ANY setup will revert to a linear upward progression of EGTs. EGTs are primarily a function of CCP (combustion chamber pressure) which is a function of torque. heat and pressure are eventually going to get all of us. at 20 psi w my setup i am not there yet. my turbos should make 44 lbs (each) per minute at 27 psi which should be 630 rw. i need stiffer actuator springs and then we will have at it in March.

of course the question remains, what do you do when you get to the inevitable point where EGTs reach "too high." probably lots of METHANOL is the answer given it's approx 300 degrees worth of higher auto ignition protection as well as cooling and octane. probably back down on ignition as well.

this thread is quite valuable. Brian is doing some interesting things and today, w major ignition and fuel changes should prove as interesting as yesterday.

through it all the primary cause for excitement is alcohol.

consider that on an 80 degree day Brian boosted over 20 psi and had an IAT around 90 with no intercooler!!! you certainly can get along without your intercooler if you wish... for certain modes.

consider my IAT out of my intercooler at 20 psi with virtually no airflow (dyno) was 91 BEFORE my alcohol. my UIM was freezing to the touch after each run.

and consider EMP as one of the key limits to power output. you really can't run too much exhaust on a rotary.

hc

Howard I'm a bit confused on something. How are you getting an UIM that is cold to the touch? Do you have an air/water intercooler with an ice tank? An air/air intercooler (on it's own) can't cool down a charge to below ambient outside air temperatures.

"How are you getting an UIM that is cold to the touch? Do you have an air/water intercooler with an ice tank? An air/air intercooler (on it's own) can't cool down a charge to below ambient outside air temperatures."

you are correct. add 1400 CC/Min of alcohol and i suggest you might want to put your gloves on.

hc

I think you missed the whole point these smart guys are trying to make. Methanol is what is providing the cooling affect which is why BDC can run without an intercooler.

thewird

Trust me Marco, he didn't miss that. ;)

B

The thing that throws me off is that your numbers show "F IAT after intercooler before alcohol". That led me to believe that this was on gasoline with no alcohol present. Is that not correct? Were these numbers with alcohol?

Believe me I'm not doubting your numbers in any way and I definitely understand what's going on in the thread. I've even been talking to Brian on the phone about it. Your numbers just seemed to imply that you were running gasoline and an air/air intercooler and were getting IAT's lower than ambient. That's not happening though so I was just trying to get clarification to see what I missed. I know good and well running alcohol will lower temps!

Howard this is funny, it seems like we are a bunch of alcoholics :)

As for the IAT's that Howard is getting, he explained that the main reduction or first temperature reduction he is getting is the intercooler that drops to about 90 degrees ( thats IAT's after IC ) and then the AI goes in effect after the intercooler and cools down the air to extremely low temperatures and thats why he gets a LIM that is so cold to the touch.
Remember the AI nozzles are placed after the intercooler close to the Throttle Body.
Leo

Now I've got it. I just assumed there was no alcohol at all on those runs.

So he's up around 20 psi and getting mid 90's for intake temps with just an air/air intercooler? That's just amazing to me. What were the ambient outside temps? Then of course alcohol lowers it even more.

Jan 23 09 Update
 

Went and put a bit more seat time in after updating the ignition curves at 15+psi. I only had bout 20mins worth of time and only really got about 5 runs in; a few of which were decent. The traffic was building up already for Friday late afternoon rush hour so I couldn't do a whole lot. I think I need to get this off the road and stick it on a dyno. It'll also not only give me the ability to run out the RPM a bit higher and make sure the upper RPM fuel maps are set but it'll also help with logging an air/fuel ratio per the dyno's independent w/b.

Today's ambient temps were a couple degrees cooler than yesterday. The IAT's logged at relative boost pressures were unchanged as I expected. I ran up to about 23lbs of boost and saw the IAT's settle between 95-98*F. My boost is a bit shaky and I'm not sure why. Could be the source to the controller's internal pressure sensor is on a runner source and is therefore pulsy or could be because I'm using pretty inflexible -4AN stainless-steel braided lines from the pressure source (that is pulsy), to the controller solenoid, to both ports of the wastegate. Wouldn't mind some input on this.

I did a little work on the fuel map and adjusted the Gain up a few 10th's of a notch. I'm trying to target for 10 flat:1 AFR's at target boost up to redline. I'm pretty close to it up to 7krpm from 15 to 22-23psi. Unfortunately my old PLX unit reads "rich" below 10:1 so it's difficult to ascertain what's going on there. I'm planning on swapping to an NGK Powerdex which will work just fine for that.

The major change on the map today was per RXHEAVEN_WA's indirect suggestion of removing lead advance at progressively higher boost levels per what the WI guys on ausrotary.com are doing. I was running 16*BTDC Lead advance at 15psi to 13*BTDC at 30psi (about 14-15* at 22psi). I changed it to 14*BTDC Lead advance at 15psi and 3*BTDC by 30psi. Logged, at 22-23psi, Lead advance is sitting between 7 and 8*BTDC (bar 26-27). I am still using an 8* split from 15psi on above tapering to 0* backwards by 0"/0psi. To my surprise, I didn't have to change anything in the fuel map nor did the car feel any different power-wise. I expected with as large of a Lead advance change at 1.5bar to have to add a good chunk of fuel and re-linearize the fuel curves but didn't have to. I was initially skeptical of this Lead advance change but now I'm not.

I'm still scratching my head over EGT's. At 7000rpm at 15-16psi, my EGT's reached 1692*F. At higher boosts, I am hitting right at 1700*F if not over a bit in the 6krpm range. I'm still not sure what's considered safe.

B

When you taking this bad boy to the track, would love to see what numbers it runs....

Jan 23 09 Datalog
 

Just one datalog this time, BDCHA29. Appears to be 4th gear but I could be mistaken. I'm only showing this so some data can be viewed for IAT's, Lead advance * changes, and corresponding EGT's. EGT to 5V quick conversion chart:

1800*F 5.00VDC
1764*F 4.90VDC
1728*F 4.80VDC
1692*F 4.70VDC
1656*F 4.60VDC
1620*F 4.50VDC
1584*F 4.40VDC
1548*F 4.30VDC
1512*F 4.20VDC
1476*F 4.10VDC
1440*F 4.00VDC

BDCHA29

http://bdc.cyberosity.com/d/14151-1/bdcha29-1.jpg

http://bdc.cyberosity.com/d/14153-1/bdcha29-2.jpg

http://bdc.cyberosity.com/d/14155-1/bdcha29-3.jpg

http://bdc.cyberosity.com/d/14157-1/bdcha29-4.jpg

It'll probably explode right now if I took it to the track. I still need to get it dialed in right and do my best to make sure stuff is ok on it. I'm not done tuning it. Needs a few hrs of dyno time.

B

Nice project, keep up the good work....

I'm wondering where the EGT's will settle as well once you're able to wind it out with boost....They really begin climbing later on when the boost is in it, but its only making full boost for about 1200 RPM of the logs...my car seemed pretty setteled around 1700F by 6200, but that was as far as I could go as well....I'll find out next season though :)

On your boost controll issue - what size spring are you running?

interesting data today. i assumed such a major ignition curve change would have done something re your EGTs. but no.

so now you are major rich, have very little advance and are at 1700 at 6100... since you now have done the ignition thing maybe then next step would be to lean it out to the 11.0 area and check your EGTs. i doubt if adding more fuel is going to help.

hc

I agree with Howard..

Being that rich hasn't changed the egt's, and will make less power. I think adding too much fuel can cause an increase in EGT's because the excess fuel ignites outside of the combustion chamber increasing the temps where the EGT probe is. Leaning out to 11 should still be plenty safe and you can see what the EGT's do. At least if they stay the same you will have more power.

As far as your boost fluctuating... what boost controller are you running? Wastegate spring should be at least a 12 psi spring. Make sure your BOV isn't leaking. And make sure the gain on the boost controller isn't too high. Also because you're not running an intercooler the air source in the piping is more turbulent. (not sure where your EBC is sourced) Some people have smoother boost control after the intercooler. You might be able to try a pill in the line to smooth the response out,(works for gauges anyway) this might increase your boost levels so be careful and retest your boost settings carefully.

For both Dude and Howard -- Well I'm not sure I'm really all that major rich. I think it might be an apples and oranges comparison here. I'm considering the possibility of either the wideband's output reading being thrown off from the mix of gasoline and alcohol or the engine, with this odd mix of fuel, needing a different point to tune. Even though it's pretty much a/the accepted standard for tuning boost w/ pump gas type stuff, I really don't think this low 11:1 AFR is anything magical or cemented in stone to the point of transcending away from 100% gasoline tuning. It seems the rules change here. I can run this at high 9's:1 and the motor doesn't misfire whereas on an all gasoline setup if I'd hit 10.50's or lower the engine would be complaining and losing power. My gut along with what I've learned from this past week of hammering the car is that I ought to focus more on the EGT itself and make the air/fuel ratio contingent on it. I can give leaning the fuel portion out a try to pull the AFR's leaner (perhaps to low 11's:1) but I think the EGT's will rise. In this case, I'm treating AFR's as arbitrary but I will atleast give it another try, leaner and richer w/ gasoline map changes only, to see if the EGT's drop or rise with the same boost and same conditions.

I'm using a 10lb spring IIRC. Not to invalidate the suggetsion, but now that I know the hot-air setup works, I don't mind upgrading to a stiffer spring but I'll tell you that I've done this at slightly higher boost before, on the same gate, with a 5.5lb spring just fine. I think in my situation the input to the controller is too pulsy per the source. During my last setup change in late '07, I changed entirely how I do all of my vacuum plumbing. I'm considering tomorrow building a small 4-way brass vacuum splitter and moving the controller input off of the UIM/LIM rear-center runner (location for the factory pressure sensor) and scootching it over to the source for the MAP sensor and FPR; bottom, 3rd nipple of the three nipples on the front of the UIM just aft of the throttle body.

If I wind up using a pill I'll consider your advice Dude as I've assumed the same thing. Would be quite a fun surprise to stick a pill there, keep high boost setting the same, and go zoom zoom straight to 2bar. :D

B

Well, I will throw a few things out there regarding the AFR's.

The first is that o2 sensors read the amount of free oxygen in the air. So the fuel type doesn't matter, and won't affect or skew the readings.

A couple possible reasons why your engine is able to run richer with the alcohol is the fuel type is different and has different burning characteristics, and also being injected so far up in the air stream it can better atomize with the incoming air making for a better combustion process. The downside to this would be less precise metering of the fuel, which is less of an issue with only 20- 35% being replaced here.

But, just because a fuel allows for a richer mixture doesn't make it optimum.

Next, Howard is running a similar alcohol setup. Actually running a bit more alcohol IIRC. His afr's are in the mid 11's and his EGT's are low. Lower then optimum actually. Really the only differences in his setup are his twin turbo's with the quite large downpipes, the intercooler, which may allow for a 30* - 40* drop in intake temps after the alcohol is injected and maybe 5- 10% more alcohol flow.

I doubt the intercooler has anything to do with why his EGT's are low, I doubt the slightly higher alcohol flow is the reason. Really the only 2 things it could be is the less restrictive exhaust or the leaner AFR's. One thing his setup does show is that leaner AFR's in itself will not cause an increase in EGT's.

The last point I would like to mention is a mishap that Howard mentioned in one of his threads where his FPR had no boost source and didnt increase fuel pressure. His AFR's spiked to 13 with no knock. I don't know if his EGT's were mentioned, but maybe he can chime in here about that. At the time when I read about it, my impression was leaner AFR's might be able to be utilized with alcohol, and well water also but that's not what we are discussing here. One other thing to note is he picked up 30 HP with that mishap.

Regarding the Boost fluctuations, I'm leaning towards the vacuum source as well. I would think a 10 lb spring would work, the general idea is double the spring pressure for the max boost the spring can properly control, but it doesn't seem like a couple psi would make a huge difference. The only other thought would be if you have any leaks in your line or diaphragm causing the pressure to bleed off going to on it the gate.

Just a couple more thoughts on your EGT's. I don't think the EGT's you are having are really THAT dangerous. 920-950*C or 1688- 1742* F are about the upper limits for turbos. So you're right in that area, but some people have reported seeing 1000-1100* C *(1800-2000 +*F) pre turbo temps! EEk!



HEAT RETENTION CAUSED BY EXHAUST BACKPRESSURE

Besides the downpipe size that I previously mentioned, there are several other factors that can increase exhaust back pressure which can lead to heat retention and higher EGT's:

1. Manifold design (log vs tubed especially)
2. Wastegate size/flow (35mm vs 50 or 60 mm, single vs twin gates, dumped vs rerouted)
3. Turbine housing size / Turbine wheel (you're running the .96 and.... Q trim? which should both be big enough)
4. Downpipe size (3" vs 3.5 or 4")
5. Midpipe (straight pipe vs catalytic converter)

The rest of the exhaust would also be a factor, but anything close to the turbo will play the biggest role. Back pressure, especially at elevated boost levels will have an effect on higher EGT's, as is evident with the many stock turbo manifolds (restrictive) having cracks from high heat.

I'm not thoroughly familiar with your setup, but you might consider EBP as a condition leading to higher EGT's, and look over your setup and decide if anything could be a restriction in the flow department, that might lead to higher exhaust back pressure. Just a thought.

Brian, time for that full 4" exhaust :)

thewird