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Lol, get ready for the bug. You are going to be throwing injectors and rods in that thing before you know it.
HEhe.. i am afraid it will come sooner than later.. i do already run 700cc denso injectors though.. and e85.. but there can allways be more.. although it felt already at 300~wNm like i was very sceptical if this powertrain really can stand that much stress.. perhaps i need to lower my max-power and take in account that i spend some of it for the SC (but still stress the rods with it).. (so the difference between engine torque and wheeltorque is greater on my setup.. )
My FMII (351 lbft rating) is currently my tq fuse. I tune to limit based on clutch. If it slips, dial it back.
6 speed is stronger than 5 speed. Most 5 speeds are consumable with agressive driving at 300whp. Some hold past that, but they are the outliers. I killed one and hurt another at 220 lbft. 6 speeds are known to fail at some rate above 300whp. They can become consumable someplace between 350 and 400whp with agressive driving.
I am on major iteration 3 with tons of sub-iterations for the cooling system. Now running all the things with the TSE rad, 60 row series-1 Setrab oil cooler, ducting, venting, reroute, ...
My FMII (351 lbft rating) is currently my tq fuse. I tune to limit based on clutch. If it slips, dial it back.
6 speed is stronger than 5 speed. Most 5 speeds are consumable with agressive driving at 300whp. Some hold past that, but they are the outliers. I killed one and hurt another at 220 lbft. 6 speeds are known to fail at some rate above 300whp. They can become consumable someplace between 350 and 400whp with agressive driving.
I am on major iteration 3 with tons of sub-iterations for the cooling system. Now running all the things with the TSE rad, 60 row series-1 Setrab oil cooler, ducting, venting, reroute, ...
This is a street car.
hehe.. yeah.. keep telling yourself it is a street car!
I think i need to guesstimate the max wtq around 200 instead, and guessing that the supercharger perhaps eats away about 20 in parasitic loss..
since the discussion above the idea of turbo first has gotten stuck in my head.. but it means then, that i would have to put a filter straight on the turbo not being able to feed it fresh cold air from away from the manifold and all that.. and it will also give the possibilitie of using the turbo more freely .. but also if going back to 130/62.5 pulley setup i could raise the rev again to 7500 .. and loose a little of down low torque.. i don't think the turbo would compensate for the lower pulley gearing as low as the gearing otherwise give boost..
tomorrow morning i will pickup the new turbo.. before then i plan to move my oil feed and prep for install.. perhaps this weekend i can have it running again!
At first i will have it in sc first setup though.. just to compare with before.. maybe i will be happy with it, not worth rebuilding things..
Going back to 130/62.5 would be a step in the right direction IMHO.
Some very rough back of the envelope guessing here, comes out to a pressure ratio of 1.65, about 9.5 psi of boost, 55% efficiency (off the MP45 map) and around 550 cubic metres of airflow per hour at roughly 14,500 blower rpm.
More rough guessing, about 323 CFM and perhaps 215 gross flywheel Hp from just the MP45.
Ummm... maybe 185-190 at the wheels ?
That MP45 is going to soak up a bit.
If you compound that with a turbo, it will all increase by roughly the turbo pressure ratio, and interestingly it will stay at the same position on the MP45 map.
So how about a 1.35 turbo pressure ratio (5psi from the turbo) blowing into the M45.
Final pressure ratio 1.35 x 1.65 = 2.22 or 18 psi.
An 18Lb wastegate spring should end up with about 5psi coming from the turbo.
Gross flywheel power 215Hp x probably about 1.3 = 280 Hp
How does that sound ?
Those are roughly the kinds of figures I am aiming for myself in my own build.
Going back to 130/62.5 would be a step in the right direction IMHO.
Some very rough back of the envelope guessing here, comes out to a pressure ratio of 1.65, about 9.5 psi of boost, 55% efficiency (off the MP45 map) and around 550 cubic metres of airflow per hour at roughly 14,500 blower rpm.
More rough guessing, about 323 CFM and perhaps 215 gross flywheel Hp from just the MP45.
Ummm... maybe 185-190 at the wheels ?
That MP45 is going to soak up a bit.
If you compound that with a turbo, it will all increase by roughly the turbo pressure ratio, and interestingly it will stay at the same position on the MP45 map.
So how about a 1.35 turbo pressure ratio (5psi from the turbo) blowing into the M45.
Final pressure ratio 1.35 x 1.65 = 2.22 or 18 psi.
An 18Lb wastegate spring should end up with about 5psi coming from the turbo.
Gross flywheel power 215Hp x probably about 1.3 = 280 Hp
How does that sound ?
Those are roughly the kinds of figures I am aiming for myself in my own build.
Well.. it sounds great but not the numbers i experienced so far with this blower.. with that ratio and a non restrictive exhaust manifold (although ported original) i saw about 163whp and 0.27bar of boost. After that i did a pressure-test of the system and no leaks.. and then i decided to run a 146/62.5-ratio instead which got me up to 0.3-0.34 in boost. (bar again).. and also i don't think i want to go that high as 18psi on compoundcharging.. at least not at this stage.. again, i am running stock engine.. but let's see, perhaps the torque-curve will still allow it (i am letting it dictate my limits, since i believe that Torque is the killer, perhaps second to revs)..
I have been thinking about this alot.. but let's see.. i think i want to do the turbo-first setup this winter instead, so i won't experiment away the whole summer.. SC-first will definately be good enough for now, and i want to see how the new turbo changes things in the "same" setup..
Other than that, i agree with you.. i think turbo first erases some of my experienced issues.. and also it protects the turbo since a sc-failure does not fill it with scrap metal if that would ever happen.. (bought the sc used from the us. and did a bearings-renovations on it without taking apart the rotorpackage and i don't know if it is good or how good it is.. so i am a little reserved to when it will grenade )..
So today i had to prime the oilpump to get it to flow at all.. this indicates that it might be breaking soon or the pressure valve is on strike/fighting.. i am not sure it is because i used 10w60 before.. what do you guys think about this?.. is it common and just something to shrug about or a clear warning?
it never happened to me before but then also i might have drained some parts when testing / troubleshooting turbo oil feed, that i normally don’t do..
You already know that you had debris in the oil system.
If it was me, I would proceed with extreme caution. One would think the filter would catch anything and prevent blockage, but starvation can kill a motor quickly.
Edit: I will say I had to prime the last time I fired up a dry motor that didn't have grease in in the oil pump.
I would do two things.
Cut open the oil filter and have a look inside.
Pull the oil pump off the front of the engine and have a look at that too if there is debris in the filter.
The oil pump gears have been known to spontaneously explode at high rpm, but they are also known to become loose on the crankshaft flats, and slowly fret and disintegrate, shedding bits of the sintered gear material in the process.
Check out a set of Boundary Engineering billet oil pump gears. Not exactly cheap, but they have an excellent reputation.
You already know that you had debris in the oil system.
If it was me, I would proceed with extreme caution. One would think the filter would catch anything and prevent blockage, but starvation can kill a motor quickly.
Edit: I will say I had to prime the last time I fired up a dry motor that didn't have grease in in the oil pump.
Yes, i think i will.. i will keep a very close eye on the oil gauge for indications that it has issues again. I'm not sure that this issue means it will drop in mid-run but perhaps most sensitive at startup.
I did an oil change to look for clues of failure and found nothing, i also changed the oil filter incase it was blocked by something, and to be fare the debris was not metal, but thread tape, and in the oil before the filter, not after so i doubt that more of that would be later in the system.
Originally Posted by Warpspeed
I would do two things.
Cut open the oil filter and have a look inside.
Pull the oil pump off the front of the engine and have a look at that too if there is debris in the filter.
The oil pump gears have been known to spontaneously explode at high rpm, but they are also known to become loose on the crankshaft flats, and slowly fret and disintegrate, shedding bits of the sintered gear material in the process.
Check out a set of Boundary Engineering billet oil pump gears. Not exactly cheap, but they have an excellent reputation.
I think i will order a billet pump, do you know if it can be changed with the engine still in the car or do i have to pull the engine for that one?..
I will put the car together now, with one eye on that oil pressure, and let's see if it will spook up on me again or just decied to play now.. and if things survive until the winter i will then do a pump replacement if i can get hold of one of those billet pumps!
Well.. i discussed with some friends about the need to prime sometimes and that the oil pump might be a little bit tired after 22years.. (i doubt that it has been changed).. so i put it together.. started up with oil pressure emediately, then took it for a drive with turbo only.. spool started at 3000rpm and full boost at 4000rpm.. then let it sit over night to test oilpressure again the day after (today) .. and oil pressure problem seems to be gone.. i am guessing that the check valve in the filter is helpig the pump to keep that priming oil which keeps it working. I mounted SC today and did another testrun and no sign of oil ghost problems so i will keep an eye on the oil gauge and drive like this for a while..
New turbo experience.. now the turbo starts spooling at 2000rpm and reaches full boost (12psi) at 3000rpm, and then i hit a SC flow restriction at 5000rpm which makes it plateau a little but still pulls nicely till 6500rpm (rev limit).. the torque-curve is much broader now and it almost doesn't feel that strong at all until you look outside and see the world pass by in warp speed.. and all the roads shrink again.. i will look into addressing that air-starvation that i see on higher boost for the turbo, maybe a waste-gate.. or perhaps a turbo-first setup i checked and there is space for it.. but i don't want to lose that good sc-push right off throttle.. it makes a big differens with 3psi and 6psi on the first 2000-2500 rpms.. when i drove the car with only turbo, not much happened between idle and 3krpm.. and coming back to boost on gear changes was also slowish.. and still this turbo (gtx2867r .64) is really not slow spooling, it feels very responsive.. especially compared to the "old" gt2871r .86 ..
Car pulls strong but will need a good overhaul soon.. some service stuff..
I bet you could plumb an external wastegate across the SC without too much brain damage. This will help get past the flow restriction you are seeing. Use say, a 10 or 11psi spring.
I bet you could plumb an external wastegate across the SC without too much brain damage. This will help get past the flow restriction you are seeing. Use say, a 10 or 11psi spring.
Exactly.. i also thought that i could put a filter no that snout then so it wouldn't suck in unfiltered air when opened.. I have checked and it is cramped but enough space to make it work..
Checked another "to fix"-thing on the list the other day.. a windshield wiper tank to replace the one not fitting anymore.. ordered this one after a tip from another Miata owner in the local sports car club.. =)
I am planning now to reroute so that i can run turbo first, feeding the supercharger.. this summer i have ben able to give alot of attention to the car but i had to have a little break now because of life.. and perhaps especially family life..
so to be able to bring the car to the track now later in august i just "solved" this issue by inserting a piece of 2,5" pipe in that hose that collapsed and will run it this way until i can rebuild.. it solved the issue with the boost drop and the car is currently now boosting around 11-12psi peak boost which also is where i want to be, not to grenade drivetrain and or anything else.. (hopefully!)..
since the gears 1-3 goes by so fast it doesn't really have time to build boost early/peak until 4th/5th gear.. which makes the car feel like instead of fading off, just taking off in the higher gears.. my brothers first reaction was "dude, you GOT to get a new gearbox!".. .. that 2seconds following that with "oh no!"-feeling in my gut.. was interrupted when he added "i ran out of gears so fast!"..
another thing i need to look into is that the chassie does not handle this new torque perfectly.. the car now is feeling more loose and i have some improvements to do.. diff bushings are definitie priority.. i have a new set on the workbench.. i think this is what makes the car feel a little like a boat on throttle.. and the tail walks a little off and on throttle.. (without any wheelspin).. (it might be amplified by the 17"-inch street wheels i have on not to wear out my race-tires on the street)
hopefully i will be able to find my gopro soon (we just moved to a new home) and can do some driving clips for you guys..
Some pseudo scientific tests (i know the 2nd gear doesn't exactly reach 6500rpm in this graph because it tapers off a little to the end, but revlimiter can be adjusted so those 115rpm that are missing is added).. . here is k-miata-calculator https://kmiata.com/pages/gearing-calculator(gearing vs. topspead per gear) and a cutout from some logged pulls from yesterday evening.. 0-60 seems to be done in a little over 5.1s .. which is decent i think.. clearly an improvement from stock power atleast..
Keep in mind i am assuming i have a 3.9-diff. (which i don't know, but i think is a fair guess)
When i analyze the time it takes to go through the gears it seems like revlimiter is hit on 1st gear after 2.5s, 2nd gear after another 2s after shifting.. and then 3rd gear after yet another 3.3s.. (seconds per gear shifting up not total of all gears)
07-22-2020, 10:04 AM
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