318is with Rotrex C30-94 Supercharger
Moderator: martauto
Hi Steve,BMUU wrote:Hi, what might you suggest for someone wanting to cheaply (comparitively) roots type supercharge a stock M42 with the stock 10.5:1 compression Geoff?
thanks, Steve.
You could also consider a Toyota SC12 roots pump as found on the Toyota 4AGZE engine. I stand corrected, but I think you might find one of these in the back of an old MR2. However, since the Eaton M45 is well known on this forum, it's probably your best option. If, however, you can't find one off a mini and decide to go direct to Eaton for one, then rather have a look at some of the other roots pumps they have to offer. Easiest route though, as Appletree said, get an M45 off a mini.
Regards
Geoff
Result the new charger is here and fitted started the running in process and should finish it tomorrow. Then its time to give dave walker a quick ring and see if he can fit it in one evening for a remap to make sure its all ok
C30-84
C30-94
The new charger is obviously different, the impellor looks smaller with more blades and the the shaft is also different.
The inlet size is also reduced although only at the end nearest the impellor so all the pipe work still fits perfect.
cant wait to get it running again, only thing i need to wait for before a propper run is abit more charger oil as its towards the min level although still more than ok for running in, at £70 a ltr its dear stuff to!
C30-84
C30-94
The new charger is obviously different, the impellor looks smaller with more blades and the the shaft is also different.
The inlet size is also reduced although only at the end nearest the impellor so all the pipe work still fits perfect.
cant wait to get it running again, only thing i need to wait for before a propper run is abit more charger oil as its towards the min level although still more than ok for running in, at £70 a ltr its dear stuff to!
You should never underestimate the predictability of stupidity
M42 Supercharged 285bhp + M3 6speed box
Fantastic stuff Matt, way faster than I expected. Takes me ages to get nice new performance parts shipped down south. Sometimes they take so long that when they arrive I've forgotten which project they are for
Is that an 80mm pulley on the Rotrex?
I see you have Corky Bell's Supercharger book on your table. Great reference that!
In theory (at least) you shouldn't need to have a remap since all the supercharger is doing is controlling the amount of boost as a function of RPM. Choose your pulleys as we discussed before and you should be producing roughly the same boost with RPM (with the exception that this time you won't be close to the surge area of the compressor flow map).
In practice, however, if you do happen to cross over areas of the fuel or ignition map (because of a different amount of boost than anticipated) that were previously unmapped (because the last compressor never went there) then you will run into problems.
I assume that you'll have her mapped to above 10psi boost only once you get the lower compression engine in?
Good Luck! I really do hope you get the results you are looking for. I can't wait to hear how she performs.
Regards
Geoff
Is that an 80mm pulley on the Rotrex?
I see you have Corky Bell's Supercharger book on your table. Great reference that!
In theory (at least) you shouldn't need to have a remap since all the supercharger is doing is controlling the amount of boost as a function of RPM. Choose your pulleys as we discussed before and you should be producing roughly the same boost with RPM (with the exception that this time you won't be close to the surge area of the compressor flow map).
In practice, however, if you do happen to cross over areas of the fuel or ignition map (because of a different amount of boost than anticipated) that were previously unmapped (because the last compressor never went there) then you will run into problems.
I assume that you'll have her mapped to above 10psi boost only once you get the lower compression engine in?
Good Luck! I really do hope you get the results you are looking for. I can't wait to hear how she performs.
Regards
Geoff
Ya, your right well spotted Geoff its been a brilliant book and is somthing i keep coming back to for info on both builds
been for the first test drive today/run in period.
Primed the charger using the compressor to make sure it had a good feed of oil, then ran it with return line going in to a bottle just for a few seconds to check the oil had filled the system.
Topped up the resivour
started the car and let it idle till the engine was up to temp.
Went for a run to my mates garage staying below 2500rpm for 25miles (25miles left of running in period at below 2.5krpm)
First impressions are good, car seams to be more responsive lower down with no hesatence and making a little more boost than the -94 did, AFR's according to my AEM gauge are between 13.7 and 14.2 at light throttle opening 13.5 at mid throttle
Also so far i have not been able to hear the charger surge/chatter at the lower rpms like the -94 did.
there was also a slight worbeling noise that the inlet maifold used to make at larger throttle openings lower down it sounded like the manifold was pulsing slightly but could be stoped by putting one finger on the centre of the manifold and applying pressure the exhaust also used to make a raspy noise abit like a e46 m3 at the same sort of rpm as the inlet worbled which i had put down to the inlet manifold not being internaly braced and flexing although it is quite thick material its made from.
either way both noises have now disapeired completely it now sounds alot deeper note from the exhaust to which is more to my liking, the charger has also got more of a whistle to it now at idle, there no way you would think its standard under the bonnet anymore. 
Will post some update pics in my other thread later
I am one happy zoner today
been for the first test drive today/run in period.
Primed the charger using the compressor to make sure it had a good feed of oil, then ran it with return line going in to a bottle just for a few seconds to check the oil had filled the system.
Topped up the resivour
started the car and let it idle till the engine was up to temp.
Went for a run to my mates garage staying below 2500rpm for 25miles (25miles left of running in period at below 2.5krpm)
First impressions are good, car seams to be more responsive lower down with no hesatence and making a little more boost than the -94 did, AFR's according to my AEM gauge are between 13.7 and 14.2 at light throttle opening 13.5 at mid throttle
Also so far i have not been able to hear the charger surge/chatter at the lower rpms like the -94 did.
there was also a slight worbeling noise that the inlet maifold used to make at larger throttle openings lower down it sounded like the manifold was pulsing slightly but could be stoped by putting one finger on the centre of the manifold and applying pressure the exhaust also used to make a raspy noise abit like a e46 m3 at the same sort of rpm as the inlet worbled which i had put down to the inlet manifold not being internaly braced and flexing although it is quite thick material its made from.
either way both noises have now disapeired completely
it now sounds alot deeper note from the exhaust to which is more to my liking, the charger has also got more of a whistle to it now at idle, there no way you would think its standard under the bonnet anymore. Will post some update pics in my other thread later
I am one happy zoner today
You should never underestimate the predictability of stupidity
M42 Supercharged 285bhp + M3 6speed box
Matt, this is fantastic news, well done! You must feel well chuffed for sure. Next time I'm back in the UK I'm going to have to ask you if it's OK for me to see your car. Maybe you can take me for a spin some time, if that's OK with you?appletree wrote:I am one happy zoner today
Its difficult for me to say without seeing your setup in person, but I suspect that the worbling you described was also surge. At low RPM you were way off the left hand side of the compressor map with the old C30-94. I think you'll find that what's happening now is that your smaller compressor wheel is able to sustain even a small pressure drop acoss it at low RPM without the airflow across it stalling. What was happening before is that the slight pressure would build in the manifold, the airflow would stall across the compressor blades, the pressure would release back through the compressor, and so the process would repeat at probably around a few to a few tens of pulses per second. If there is any flex in your manifold/plenum then these pressure pulses would have caused the flexible area to vibrate in sympathy.
In a nutshell, your old compressor wheel was too big - and low airflow through a large compressor results in the airflow stalling! Its the same reason why a small aircraft can fly slower than a jumbo (well kind of, but I think you see the parallel).
I am glad it's working out for you Matt. With all that theory we went through it crossed my mind more than once - what if I'm wrong?. I'm relieved that I didn't make the situation worse for you!
BTW, what size pulley wheel are you using. No problem if its still the 100mm, but I suspect things will only get better when you have the 80mm on there.
Geoff it would be a pleasure to take you out, your more than welcome, just thet me know when your next over here.
I must say i'am pleased you were right to! Lol taking advise (no disrespect) from a unknown stranger thousands of miles away about something as expensive as a supercharger was abit of a gamble but when the facts are there in black and white it is easyier.
Now the results, so far anyway show that it was the right diession to make an i've no reason to think the results will be any different as the revs increase.
As for the noise on the inlet, once we started talking about surge the more i thought about and listend to the noise it was making sence that the noise could be due to the air pulsing in the inlet trackt.
Cant wait to get the charger run in an see how it performs higher in the revs.
I'm running with the 80mm pully, there £90+vat so its better to spec one with the charger when you order it.
I must say i'am pleased you were right to! Lol taking advise (no disrespect) from a unknown stranger thousands of miles away about something as expensive as a supercharger was abit of a gamble but when the facts are there in black and white it is easyier.
Now the results, so far anyway show that it was the right diession to make an i've no reason to think the results will be any different as the revs increase.
As for the noise on the inlet, once we started talking about surge the more i thought about and listend to the noise it was making sence that the noise could be due to the air pulsing in the inlet trackt.
Cant wait to get the charger run in an see how it performs higher in the revs.
I'm running with the 80mm pully, there £90+vat so its better to spec one with the charger when you order it.
You should never underestimate the predictability of stupidity
M42 Supercharged 285bhp + M3 6speed box
Thanks. I'll let you know when I'm next over.appletree wrote:Geoff it would be a pleasure to take you out, your more than welcome, just thet me know when your next over here.
Ooops. I missed the captions on your photo's. 'Was looking at your second photo thinking it was the C30-84appletree wrote:I'm running with the 80mm pully, there 90+vat so its better to spec one with the charger when you order it.
. 'Can now clearly see that the pulley in the first photo is smaller than that in the second. Excellent! Well sounds like you are pretty much set to give her a good test once you have run the new Rotrex in? I look forward to hearing your results.
Last edited by GeoffBob on Sun Jun 21, 2009 2:02 pm, edited 1 time in total.
Just had a look at your E45 project page again Rich. Can see you have definitely made progress since I last looked at it. Truth is, any progress is progress. I'm guessing that relocating your alternator is a major milestone achieved. 'Look forward to hearing your results too.rix313 wrote:All be it at a glacial rateappletree wrote:rix313 is doing the swop now
Ya abit, been working realy hard to get some hours in before i have next week off.
Ive got the charger run in properly now, first to 4.5k seam just as strong as before but smoother some how.
As said ive got the next week off so i'll have some time to get some testing done like last time.
My dads tacken the pressure tester to work to get it calibrated although it did seam to be acurate but as we've got the time.
Dad also got a bargin at the auto jumble on sunday, he picked up a brand new twin input temperature logger that downloads to the PC!!! so we can get some realy good data and i dont have to rely on having some one sat next to me to wright down what the temps are at each revs!
So far realy happy with the new charger seams to be much more responsive and still have the kick it had before although its now a sooth build how it should be reather than a laggy turbo nothing then lots delivery it had before
Ive got the charger run in properly now, first to 4.5k seam just as strong as before but smoother some how.
As said ive got the next week off so i'll have some time to get some testing done like last time.
My dads tacken the pressure tester to work to get it calibrated although it did seam to be acurate but as we've got the time.
Dad also got a bargin at the auto jumble on sunday, he picked up a brand new twin input temperature logger that downloads to the PC!!!
so we can get some realy good data and i dont have to rely on having some one sat next to me to wright down what the temps are at each revs! So far realy happy with the new charger seams to be much more responsive and still have the kick it had before although its now a sooth build how it should be reather than a laggy turbo nothing then lots delivery it had before
You should never underestimate the predictability of stupidity
M42 Supercharged 285bhp + M3 6speed box
Great work Appletree. As I said before, I don't expect the C30-84 to make too much of a difference to your peak HP figures. No doubt you are making a little bit more torque lower down (hopefully we have ironed out that dip/bowl in your earlier torque curve) but this is as a result of a) keeping you away from surge and b) changing the pulley. I'm keeping my fingers crossed that when you put her on the dyno you'll get somewhere close to 275hp at your 6500 red line.
Fantastic find that temperature logger! Brilliant bit of kit that. Does it work with thermcouples? If so then be sure to use the smallest/thinnest thermocouple wires you can get hold of for your temperature probes. The smaller the probe the lower its heat capacity, and therefore the quicker it heats up and down. Larger/fatter probes (like those those in a stainless tube) take time to heat up/down and often tend to yield deceptively low temperature values during short bursts of acceleration/boost.
Fantastic find that temperature logger! Brilliant bit of kit that. Does it work with thermcouples? If so then be sure to use the smallest/thinnest thermocouple wires you can get hold of for your temperature probes. The smaller the probe the lower its heat capacity, and therefore the quicker it heats up and down. Larger/fatter probes (like those those in a stainless tube) take time to heat up/down and often tend to yield deceptively low temperature values during short bursts of acceleration/boost.
I'll have a look when i'm back from site, think it will use thermocouples and if there big ill try and mod them.
Lookin forward to doing some testing and getting some results posted up.
Like i said i'm going to build the low comp lump up over christmas so it wont be in full trim till the start of next year.
How ever i might see if dave walker could fit me in again for a comparison dyno run and push the current red line up a bit and see how shes running then which will give a pritty good indication as to what the new power would be.
Lookin forward to doing some testing and getting some results posted up.
Like i said i'm going to build the low comp lump up over christmas so it wont be in full trim till the start of next year.
How ever i might see if dave walker could fit me in again for a comparison dyno run and push the current red line up a bit and see how shes running then which will give a pritty good indication as to what the new power would be.
You should never underestimate the predictability of stupidity
M42 Supercharged 285bhp + M3 6speed box
Bit of progress today did some temperature testing using the same equipment as last time to try and keep it some sort of of fair test.
Temperature on the day 2c difference in metres rotrex side read 17 inlet metre read 15
Rotrex side
Idle -18c
2000rpm - 25c
3000rpm - 31c
4000rpm - 37c
5000rpm - 46c
5500rpm - 52c
Inlet side
Idle - 17c
2000rpm - 15c
3000rpm - 15c
4000rpm - 16c
5000rpm - 18c
5500rpm - 20c
I would say that theres deffinatly a difference in the days the car was tested on, it feels alot cooler here today and although its sunny theres a cool breeze like you get at the sea side were as IIRC when i did the first set of temp tests it was abit more humid and generaly warmer so thats got to have had an effect on the results, sure i read somewhere getting a 1c cooler inlet temp at the filter would make nearly 3c drop after the charger/turbo (Geoff care to correct?lol)
I also took a trip down the motor way to try and get some cruising results at a constant 3500rpm i was getting 44c on the rotrex out let and 19c on the inlet side this was at part throttle though for about 4miles and the readings never realy changed (+/- 1c) from after the first 1/4mile. This i iam realy pleased with these are the kind of temps i wanted to be running on the motor way were as with the old set-up at higheer motor was speed i was getting over double the inlet temps i get now, it didn't damage anything but it was always in my mind that i would have like it to be lower...
Cant do the pressure testing at the minute as the tester is at my dads house after he calibrated it but i think its producing more boost at the higher revs maybe 1-2psi just looking at my gauge on the dash and slightly more lower down as my AFR's have gone up slightly, nothing major maybe .5 of a ratio more in the low/mid rpms when at light throttle openings.
Could this be the new charger be able to maintain a constant pressure in the inlet piping rather than the fluctuation/suge i was getting from the -94
Temperature on the day 2c difference in metres rotrex side read 17 inlet metre read 15
Rotrex side
Idle -18c
2000rpm - 25c
3000rpm - 31c
4000rpm - 37c
5000rpm - 46c
5500rpm - 52c
Inlet side
Idle - 17c
2000rpm - 15c
3000rpm - 15c
4000rpm - 16c
5000rpm - 18c
5500rpm - 20c
I would say that theres deffinatly a difference in the days the car was tested on, it feels alot cooler here today and although its sunny theres a cool breeze like you get at the sea side were as IIRC when i did the first set of temp tests it was abit more humid and generaly warmer so thats got to have had an effect on the results, sure i read somewhere getting a 1c cooler inlet temp at the filter would make nearly 3c drop after the charger/turbo (Geoff care to correct?lol)
I also took a trip down the motor way to try and get some cruising results at a constant 3500rpm i was getting 44c on the rotrex out let and 19c on the inlet side this was at part throttle though for about 4miles and the readings never realy changed (+/- 1c) from after the first 1/4mile. This i iam realy pleased with these are the kind of temps i wanted to be running on the motor way were as with the old set-up at higheer motor was speed i was getting over double the inlet temps i get now, it didn't damage anything but it was always in my mind that i would have like it to be lower...
Cant do the pressure testing at the minute as the tester is at my dads house after he calibrated it but i think its producing more boost at the higher revs maybe 1-2psi just looking at my gauge on the dash and slightly more lower down as my AFR's have gone up slightly, nothing major maybe .5 of a ratio more in the low/mid rpms when at light throttle openings.
Could this be the new charger be able to maintain a constant pressure in the inlet piping rather than the fluctuation/suge i was getting from the -94
You should never underestimate the predictability of stupidity
M42 Supercharged 285bhp + M3 6speed box
Great work Appletree.
And there's a bonus: Not only is the air coming out of the C30-84 cooler, but the work done by the engine to drive the compressor in order to deliver a certain level of boost is now less (because of the improved efficiency). Thus you get slightly improved fuel economy for the same power output.
.
The lower temperatures are an indication that you are now running the compressor in a more efficient region of the compressor map. If you look at any compressor map (turbo or supercharger) you'll see concentric rings centred more or less around the middle of the flow map. Maximum efficiency of any compressor is determined by it's aerodynamic design. In your case, however, with the larger C30-94 supercharger, a much greater percentage of the work your engine was putting into driving the compressor wheel was going into heating the air being pumped through it, simply because you're C30-94 was operating so far away from maximum efficiency on the compressor map. With the C30-84 you're not dead bang on the centre of the map I know, but you're a lot better off than you were before!Appletree wrote:I also took a trip down the motor way to try and get some cruising results at a constant 3500rpm i was getting 44c on the rotrex out let and 19c on the inlet side this was at part throttle though for about 4miles and the readings never realy changed (+/- 1c) from after the first 1/4mile. This i iam realy pleased with these are the kind of temps i wanted to be running on the motor way were as with the old set-up at higheer motor was speed i was getting over double the inlet temps i get now, it didn't damage anything but it was always in my mind that i would have like it to be lower...
And there's a bonus: Not only is the air coming out of the C30-84 cooler, but the work done by the engine to drive the compressor in order to deliver a certain level of boost is now less (because of the improved efficiency). Thus you get slightly improved fuel economy for the same power output.
Yes, I believe so. The smaller compressor wheel in the C30-84 is a much better match to your M40 engine (EDIT, sorry, I mean M42 engine) and, unless you ever experience problems with your blowoff valve, I think it's unlikely that the air flow over the compressor blades will stall ever againAppletree wrote:Could this be the new charger be able to maintain a constant pressure in the inlet piping rather than the fluctuation/suge i was getting from the -94
.
Last edited by GeoffBob on Sat Jul 11, 2009 10:16 am, edited 1 time in total.
Congratulations lads”¦”¦
Amazing stuff took me three days to read and just about managed to understand it all.
Matt if you can send me on the oil reference number I might have it on the shelf where I work”¦.. if we have it there will be gallons of it”¦..
Fair play Geoff you’re a legend”¦..
Thanks for sharing the build”¦.
Amazing stuff took me three days to read and just about managed to understand it all.
Matt if you can send me on the oil reference number I might have it on the shelf where I work”¦.. if we have it there will be gallons of it”¦..
Fair play Geoff you’re a legend”¦..
Thanks for sharing the build”¦.
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this thread is nuts... good maths skills geoff... it means nothing to me lol!!
Ok looking at the oil container all i have is..
Rotrex SX100 traction fluid
Diphenylamine, CAS No: 122-39-4
Alkylphosphifo CAS No: n/a
Any of that male any sence? theres no obvious part number on it??
Rotrex SX100 traction fluid
Diphenylamine, CAS No: 122-39-4
Alkylphosphifo CAS No: n/a
Any of that male any sence? theres no obvious part number on it??
You should never underestimate the predictability of stupidity
M42 Supercharged 285bhp + M3 6speed box