Brakes Idea 1st Gen A possible different bigger brake idea and, Meth Injection and more

I recognize that what I can visualize in my head and/or comprehend may not be put into text/verbiage that another person may understand. Nothing against the other person as it has more to do with how I explain things. Perfect case is yesterday when Dave.0 talks about meth not helping the supercharger heat. I looked at that and my head went right to the downstream air flow.

The 19% pulley would be creating more boost at low engine rpms as the supercharger is spinning 19% faster than stock. At low levels of engine rpm the boost is more efficient relative to heat generation. As the rpm level increases the supercharger does not create boost in the same fashion as it is in the realm where "squeezing air together" has become so difficult for it that efficiency drops. In my case where I am not concerned about triple digit track speeds but rather low end torque on twisties, it appears the 19% will provide what I am looking for. At approximately 5,800 engine rpms the 19% will be at the same supercharger rpm as the Stock S engine.

Past this 5,800 engine rpm point, my supercharger will not be producing boost as efficient but so what? We are talking about a matter of a few seconds for the engine to go from 5,800 to redline. Hence the MI that would appear to help mitigate the heat created by the inefficiency.

 

Yes he probably could but then I would no longer have a MINI but rather a MAXI . . . . .

 

Here are some Eaton Charts and then a spreadsheet that I prepared.

The spreadsheet reflects where there are any issues with possible excessive supercharger rpms. I have not seen anything from Eaton but there are posts on the web noting that Eaton stated their M45 was rated for a maximum 16,000 revolutions. BMW/MINI decided to install a smaller pulley on the JCW that exceeds the Eaton "line in the sand." One would think there would have been a major class action lawsuit had the JCW superchargers suffered catastrophic failures and that BMW/MINI would have considered this when they released the option. With hindsight, one can see that the superchargers did not fail nor were there any waterpump cavitation issues. I am also not aware of any major issues with the 15% pulley have any major issues.

In the spreadsheet where a specific pulley exceeds the 16,000 value the cell is highlighted in yellow. Of greater importance to me is that the 19% pulley at 6500 engine rpms is less than the JCW at redline. I have not seen a representation such as this on any forum. This does not mean it does not exist but most of what I found was basically "I heard you should not do this."

 

and as far as getting it, the sentence in question was "Meth will not help the SC temps at all." The matter of whether this pertained to heat within the SC itself or in the air stream that was heated from passing through the SC was not indicated so IMO one could logically argue that there was no error addressing the cooling effect of MI regardless of whether the MI mix was 100% meth or a 70% water/30% meth.

Let's ask the Mistress which response she likes more as I could use another Gen1 in my garage . . . . . . .

 

First, anytime a liquid is atomized into an air stream a cooling affect is created. Next, if the liquid was injected before the supercharger it would help cool the supercharger for the same reason (I am not suggesting this be done merely pointing out the laws of physics). Methanol injection will lower the intake air temperature that has been heated by the compression of the supercharger. This is confirmed by many tests and the Mistress appears to benefit from a 10 - 20 degree decrease according to your previous posts.

On the matter of a smaller pulley and the son of John Cooper's involvement, Michael, I just cannot believe that an organization the size of BMW would allow an individual with no status within the organization to dictate what product was going to be used. The Tritec was developed through a joint effort of the Rover Group, that was owned by BMW at that time, and Chrysler that was owned by Daimler Benz. The lead Chrysler designer for the engine sometimes posts over on the BBB site. I don't know if he addressed the selection of the supercharger. To me there would have been a process for the selection of a means to increase the performance of the engine albeit forced induction or increased compression. Then once the manner was agreed upon the specifics for the design would have again been discussed and agreed on. IMO high level management was involved in the supercharger process and would have had testing data and recommendations for the final pulley ratio that was used.

Interesting on the Dealer supercharger matter. It is logical to me that BMW would not want the pulley to be removed at the Dealer but rather have the supercharger with the pulley installed at the manufacturing point be installed. In this manner BMW would be able to control the cost and more importantly reap more profit.

 

and back to supercharger heat, yes higher revs will create more heat that the metal of the supercharge will absorb. This heat will then be transferred to the air stream. It is logical to assume that there will be a point that the air stream will be heated to the point that even after the injection atomizing cooling will no longer keep any fuel from premature detonation.

The spreadsheet I uploaded reflects the pulley revolutions where the JCW values are exceeded. On the 19% line, this only happens after 6550. The instances that a normal driver will exceed this point are far and few between. I cannot remember ever hitting cutout in second gear but I have hit it in first. I will just start shifting sooner in first.

The Mistress is proof that the point is manageable even at engine rpms of 8,000 and supercharger rpms exceeding 20,000 rpms. It would be very interesting to have your tune mapped out to reflect timing from 6,500 engine rpms up. IMO this would be the smoking gun on where the "point" is reached.

 

and last, if I am posting too much just tell me to go back to the BBB site.

I had to make some posts over there yesterday on a thread where somebody was bashing RMW. It would have been so nice to throw in some good FUs, you are full of shit and piss offs.

 

This is just the issue that you find when doing any type of research on the matter, somebody's opinion with no data to back it up. There are numerous MINIs out there with smaller pulleys producing spin rates that exceed what some say (ah yes what somebody says) Eaton stated relative to a 16,000 limit. Well if they said that, it is obviously incorrect as there a thousands of MINIs out there relative to Gen1 JCWs that exceed the value. Nobody has showed any data on at which point the heat created predetonation can no longer be addressed by heat mitigation or by spark retardation that I am aware of.

Fact # 1 is that a 19% pulley will spin the supercharger at a rate, 6550, that is the same as the JCW cutout redline of 6,950. So the question is within the next 400 engine rpms will the supercharger be at a point where the heat produced causes significant spark retardation that cannot be addressed by MI and is there data reflecting such?

Fact # 2 is that the inclusion of atomized liquid into the supercharger, regardless of the whether the impact is severe enough to cause failure, will cool the supercharger.

Fact # 3 is that regardless what type of engine management system one has it cannot change the law of physics or thermal dynamics.

 

Why it is of course the BIG BAD BOGYMAN aka NAM.

 

Oh and I am waiting on the RMW basher to produce some "data." I even got to throw MA into the mix. This is big reason I come over here is that I can get some very thoughtful responses that I can respond to while at the same time prodding the tiger.



https://www.northamericanmotoring.com/forums/drivetrain-cooper-s/330034-looking-for-local-tuner-mass-ri-area.html

 

Will see if he is as worthy of an opponent as anyone over here . . . .

 

No my redline limiter will be my foot.

I created another spreadsheet that compares the engine rpm value of each type of pulley to the value of the JCW Pulley. I am using that JCW pulley ratio and data as the control point. Now I have found conflicting values for the cutout/redline value of the Gen1 of both 6750 and 6950. In my own experience I believe it is 6750 but my eyes are more on the road then on the gauges. My foot rev limiter really only needs to come into play for a me, what I will call a Street Driver, will be in 1st and 2nd gears. I say this for the top speeds for gears 1 through 4 are approximately (Facelift Model with 205/45-17 tires and 6750 redline); 1st = 38 mph, 2nd = 62 mph, 3rd = 86 and 4th = 105. I included 3rd and 4th gear speeds for shits and giggles. I can see myself driving in 1st to redline in normal street driving but hitting redline in 2nd for me would be limited to twistie runs. In other words, the times that my supercharger with a 19% reduction pulley exceeds the JCW Control value is very very limited. When I exceed the JCW Control Value, and I will do so, I am going on the premise that my MI will address the heat generated by the over-revs in this short 400 +/- rpm range.

Spinning too fast means nothing unless there is data behind the statement. The tune of the Mistress and how the timing is controlled is the type of data that would answer this entire matter once and for all. I will use the Mistress as the control for "too fast" as she whips it pretty good at 8000.