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The Turbosmart explanation makes perfect sense .... your comments however, don't.
Please clarify.
Are you actually suggesting that, in a system where boost is perfectly controlled at a desired level, a system with a smaller wastegate will have higher EMAP than one with a larger one?
No, per the context of the TS explanation it will allow you to run a lower boost pressure where it might otherwise not. Which is what TS is stating.
IMO the comment you put into bold: "while a small turbo run at low boost needs a bigger wastegate"
Should really say:
while a small turbo run at low boost needs a bigger wastegate............. than when it runs at high boost!
Maybe it just wasn’t apparent, but that’s actually what it says within the context of the prior part of their explanation going from the large turbo situation to the small turbo situation that you didn’t include-copy in your reply.
of course there are other factors as well … I just felt like their points clarify some things that weren’t stated correctly in various replies, or at least in how I interpreted those replies.
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IGN-1A are Mercury coils (original manufacturer is Mototron)
Lance Nist at Pantera EFI is the original distributor source and acknowledged guru for them, he can verify it if you’re in doubt. The difference in spec being stated is not correct according to all my information. Which goes back many years on here for this topic.
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Completely missed this post Team.
you seam to have misunderstood me.
the IGN1-A is based on Mercury 339 8M0077473..
test results are well known. 8-9ms dwell for full saturation, and 5ms for 90mJ
and there is the grand daddy, the two stroke racing coil (which IGN claim to be annoyingly) 300-8M0077471 - They are 180$ a piece from mercury https://www.mercruiserparts.com/8m00...vVx4graBR4UCaY, they have no aftermarket alternative (except Chinese copies)
these saturate in less than 2ms.. for the same energy as the ign1-a has.
just curious where your info is coming from, because I can’t find anything to back it up
I did find this on a boat forum for that specific Mercury coil, but the person posting it said it came from a website without listing what website it was from
In the en of the link is a Finish guy who tested heaps of coils under diferent dwell (and also overvolted).
The guy who purchased them by mistake also tested them and made a video (not that educational though).
A short dwell required would match a wankel much better and that coils is designed to run for days at 5-6000. firing/minute unlike the ign1-a which is off a 4t engines (ascan be concluded from the dwell time) thus only half firing (all marine high perf engines run in same ballpark rpm). When ypu think about it 80% duty is very short dwell at high rpm (2ms discharge also needs to be taken as load)
Did a 2.5h trackday session today. Noticed another problem this time, once the fuel tank gets under 1/4.... under hard cornering the fuel pump cuts out. This was expected but still nasty.
Brake rotors and pads, clutch, tires and possibly some bushings took a beating and will need replacing soon. Otherwise no ill effects... having a boost controller that keeps TPS in mind makes for awesome drivability. Imagine cornerning hard and controlling your lateral position on the track with the gas pedal. Compared to last time, I am no longer boosting against a closed thr. body and this helps buckets with control and predictability. Also pleased to notice that TC/DSC works just as well on a boosted car as it does on a NA slowpoke.
Can't explain why but the tune went richer as it got colder outside. Had to subtract 5% VE across the board to get back to square 1
Ambient temp. was 8C so cooling fared much better than it did last time. Temps. stayed reasonable after 4 consecutive fast laps worth about 16km.... 95C for coolant, 108 for oil(measured in the sump), 11C above ambient for IAT. In the summer oil would have gone north of 126C and oil pressure would take a dump. During these ~ 130km of track I've burned about half a liter of 2T oil and gulped down more than 3/4 of the fuel tank. Thirsy b***h....
Last edited by ciprianrx8; 12-06-2023 at 03:58 AM.
Can't explain why but the tune went richer as it got colder outside. Had to subtract 5% VE across the board to get back to square 1
Well it seems that splitting the IAT sensour out of the MAF was the reason why. Despite running the very same NTC element/scaling, merely separating it out of the MAF unit has led to this effect. It's just a theory at this time but I think that the circuitry inside the MAF also uses the voltage created by the pull up resistor in the ecu and the NTC used for IAT sensing. Take that voltage away and you no longer have the same maf voltage output regardless of temperature.
At one time when it got freezing cold outside I was getting TWICE (yes, twice!) the MAF reading that I used to get. And this was all the way from idle to redline. Naturally fuel trims maxed out towards negative(and out of closed loop the car would be undriveable due to being too rich). At that instant I had to disconnect my IAT sensor entirely. This made the MAF readings went back to somewhere decent.
Now I've went back to the factory MAF/IAT sensor but didn't test any further as it snowed and would rather not crank over the engine while cold. However tune went to siht again so at least a MAF rescaling is in order.
Last edited by ciprianrx8; 01-09-2024 at 09:15 AM.
Maf uses the iat to correct the air flow. The voltage reported by the maf only gives information asto how much the air is cooling the sensor,
this data will be same for a very large volume at high temp, and low volume at low iat.
This is why iat is placed right aside maf sensor and used internaly by the ecu.
You are deep in the bin file, you may be able to find that table but decoding it might be cery difficult :D
I'm beating a different horse here: not what the ecu does with IAT info, but what does the maf circuitry inside the sensor itself does with it. On a sluggish NA engine it makes no sense to do anything with AFRs or timing under IATs in the 0 to 40C. You'd either have to go to the extremes of a cold engine starting in Swedenistan or sth. at -40C or to Dubai at 60C to see what the ecu does there. Both cases are of no importance to most people.
Last edited by ciprianrx8; 01-10-2024 at 05:45 AM.
I'm surprised that maf setup doesn't give you tuning problems ...looks too close to the bend to me . Plus the stock maf housing tends to fall to bits when cut up like that.
This was from a year ago ..... I'm leaning towards this being part of the issues you seem to have with erratic readings. Also worth considering is that every time the maf tube is disturbed it's possible the new position can send readings out the window. Which is why a well designed setup that can easily be returned to exactly the same position and alignment every time it's removed doesn't tend to have all these issues you have. By all means test your theory about the IAT sensor but this is my theory till you come up with something definitive.
I've never had maf issues per se when ambient temps were anywhere from 15c to 40C, drove up the mountains to 2400m high and down to the beach on the same tune for the better part of 2023 on the same tune... then it got cold outside and stuff went south.
Comparing my maf setup with other OEM setups I see it is common to place bends right after the maf... I doubt it has anything to do with this. I even run the stock meshes in front and back of the MAF.
Among other stuff I've migrated my tune from N3ZHEB(what i've always run up to now) to N3ZHEC as it's a newer revision by mazda. The control logic is changed quite a lot so who knows what shenanigans I've gotten rid of just by this "power" move.
Some obvious examples: APV open RPM is coolant dependant in ZHEB, but not in ZHEC. Idle timing is load and rpm dependant in ZHEB but not ZHEC. OMP rates are higher in ZHEC.
Knock strategy is far evolved in ZHEC and kinda missing in ZHEB as far as I can tell by looking at the rom. Other tables have shrinked in size in ZHEC which lets me to believe they've cut down the useless bits at least. Example:
These were x3 the size in ZHEB.
considering that you don’t have an emission requirement to keep the factory ecu, then switching to a MAP based aftermarket ecu seems like a better way to handle it. Which gets rid of all the factory strategies that are working against performance and such.
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I've been leaking oil for months now but today I looked into it. Turbo oil feed is leaking(this alone requires an engine out job to fix). OMP output is leaking(could do with the engine in, but a pain). Pretty much everywhere oil touches, it leaks. But the worst is that the front iron has possibly cracked and leaking oil from there too. Sometime in the future a teardown is in place, but until then I'll continue to beat on it. Have never seen an external oiling system on a renesis though it's common on REWs as they replace the oil passage with solid dowels/studs. Perhaps I should do that too when I take the engine out next year or so.
I've been leaking oil for months now but today I looked into it. Turbo oil feed is leaking(this alone requires an engine out job to fix). OMP output is leaking(could do with the engine in, but a pain). Pretty much everywhere oil touches, it leaks. But the worst is that the front iron has possibly cracked and leaking oil from there too. Sometime in the future a teardown is in place, but until then I'll continue to beat on it. Have never seen an external oiling system on a renesis though it's common on REWs as they replace the oil passage with solid dowels/studs. Perhaps I should do that too when I take the engine out next year or so.
Cracked front iron at the dowel ...been there. It's why I now dowell my turbo engine. Studs (10mm) might be an alternative. Machined studs (12mm) an overkill ... IMO.
Dovel or machined tight fit studs.
clamping force is is more than enough. And trying to prevent torsion by friction can be very problematic.
A stiffer stud/bolt will in fact reduce the pressure between the plates prkvided the studsarenot pretensioned stronger than oem bolts. If the clamping is increased than at any event where flexibility would save the engine, the engine is stiff and next weak oart is damaged. By doweling or studdibg without increasing pretension, we increase torsional stiffness (which breaks the engine) but still let it move.
Dovel or machined tight fit studs.
clamping force is is more than enough. And trying to prevent torsion by friction can be very problematic.
A stiffer stud/bolt will in fact reduce the pressure between the plates prkvided the studsarenot pretensioned stronger than oem bolts. If the clamping is increased than at any event where flexibility would save the engine, the engine is stiff and next weak oart is damaged. By doweling or studdibg without increasing pretension, we increase torsional stiffness (which breaks the engine) but still let it move.
they should be adequate for a Renesis turbo, but you could take it up a step by adding additional dowels in the intake/combustion area. .
it’s not really so much the clamping force, because beyond 55 ft-lbs the rotor housings will start to deform. What the full 1/2” CNC stud mod does is tie the whole keg together rigidly to eliminate any twisting under very high torque/power. That output level is higher than any Renesis has ever seen, or ever will see. if the issue is detonation though, all bets are off. Something is going to break regardless if it rattles hard enough.
The OE e-shaft is notoriously flimsy too. I’ve concluded that more engines failed due to that than people are aware of. Not too many people are in a rush to drop several thousand USD for a billet e-shaft though.
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I read that several times actually. You can increase clamping pressure that is not even a question, but imho, its not beneficial. I am quite with Team (as wrote above) that its torsion to improve and that is very difficult with simple tension / clamping load. Ie, if you dowel you make that a shear load on the dowels, if its just tension, than its still the 20cm "pipe" twisting, with little less sliding due to increased tension. You cant transfer torsion with tension elements (I'm terrible at explaining)
"Next year or so" was actually this weekend. Pulled & tore down the engine to assess the damage. Did a compr. test before and numbers were at 6.5 bar to 5.8 bar which is as I've always had them. Never had issues starting, fuel economy was also good at 12.5-13L/100km of highway cruising so I can't complain.
As expected the front iron was cracked at the top dowel hole... where oil passes through. This was visible as soon as I took the coil bracket out.
Otherwise the engine was in very good conditions for the abuse it has been through. Housings are mint except for some burnt oil marks(no wonder, some 20 liters of oil burned in there). Side irons were a bit brown in the exhaust area, as expected due to the extra load, heat & 3x the normal backpressure. They might be heat or oil burn induced, or both. Rotors are fine, but there's some signs of blow-by the side seals. This was expected since I've clearanced them to the upper limit in the workshop engine manual. This, and pushing some hefty EMAP must have contributed to this. Apex seals are at 5.3 to 5.2mm in height so as new. All bearings are in as-new condition; eshaft is spotless too. Raising idle and relief valve opening pressures did wonders here. Orings in the oil control rings seem to be just a tiny bit no so rubber-ish so I'll be replacing them, along with all copper and anything else rubber.
So the only major part to replace is the front iron. But now I'm at a standstill as to how I can proceed, because machining parts to accept 1/2" dowels or studs is kind of out of the question - can't find anyone in this corner of the planet to do it. And me doing 0.1mm accuracy with a vertical bench drill seems like wishful thinking. Then I see stud kits that are the same diameter as the factory bolts - what's the purpose of those if they don't reinforce all the bits together? More clamping force won't cut it I assume. So it's either sticking it to lower boost levels... no more than 150kpa compared to the 190kpa I've been doing for the past year or I'll just be cracking irons on a yearly basis.
Last edited by ciprianrx8; 03-11-2024 at 02:52 AM.
Currently rebuilding with 16 1/2" studs... but messed up installation of an apex corner piece and bent it to hell. A long apex spring got itself in between the apex corner piece and main body; so when I tightened the keg the apex got bent in between the corner pieces and ended up looking like a C. Engine locked up at a particular spot so that triggered me to tear it down again. One of the most effort and money expensive f**kups I've done in a long while.
But hey, at least I managed to machine both irons and housings to take 1/2" studs without a CNC, only a manual mill made exactly 60 years ago. Out of 16 studs, just 3 needed slight polishing with sandpaper to get them to fit.
Also rebuild bucket is doing overtime. That's the 6th engine that sits on that bucket.
Last edited by ciprianrx8; 04-27-2024 at 01:19 PM.
11-11-2023, 04:10 PM
. Plus the stock maf housing tends to fall to bits when cut up like that.
