Author Topic: m42 supercharger (Read 18911 times)

doitover · « **Reply #15 on:** July 19, 2012, 06:27:21 PM »

https://picasaweb.google.com/116146659082281745739/M42DASC

There are a couple of the connection to the throttle body. I don't see it on the diagram at realoem.com but it appears to be a factory connection.

Also noticed one ICV hose is about to let go...

ReSuL · « **Reply #16 on:** July 27, 2012, 04:15:01 AM »

I couldnt mount/fit the supercharger since the nose/snout part is too long..

doitover · « **Reply #17 on:** July 27, 2012, 09:52:04 AM »

That snout looks like a bolt on piece, maybe the manufacturer can point you to a shorter one?

Quote from: ReSuL;113963

I couldnt mount/fit the supercharger since the nose/snout part is too long..

ReSuL · « **Reply #18 on:** July 29, 2012, 05:32:00 PM »

Quote from: doitover;113966

That snout looks like a bolt on piece, maybe the manufacturer can point you to a shorter one?

yeah I saw some shorter ones on the internet but they are too expensive.. I will have it shortened by a CNC or lathe (turning machine)...

ReSuL · « **Reply #19 on:** August 02, 2012, 10:07:57 AM »

ı had it shortened at last.. ı wanna ask a question.. is it possible to set the kit on the engine and go without changing the injectors and stock ECU?? or do I have to make some certain changes after installing supercharger??

axisofjustice · « **Reply #20 on:** August 04, 2012, 02:41:25 PM »

With no tuning at all you will not make good power and you will run way lean on any throttle load that adds more then 5lbs boost. At bare min for 5-8 lbs you need a wideband, a fuel pressure gauge, and RRFPR. Preferably wideband, FPSI gauge, 22-24lb injectors, and an RRFPR or a piggyback ECU such as SMT6.

Another good idea is to move to a colder plug. There is a good NGK plug to run if you are s/c, it's stocked at local parts houses and cheap! NGK V-Power BKR7E, all 4 are less than $8. This plug is one heat range colder and will make your car less likely to detonate with 91-93 octane than the standard number 8 range plug. I run these, and they are doing great.

Experimentally speaking, since my car is a very cheap project and I am still building, I read up on a car that is turbocharged and running on factory motronic and upgraded injectors. I will be trying 22lb injectors with no tune as I have read it worked so well on this guy's car. I can't say it's unsafe, it is a track car boosting 7lbs with no tune and 22lb injectors, and it has been as such for 20k miles without trouble.

I have a wideband and therefore can test without risk of blowing it up. Right now I'm untuned and have done my research I just want to stay cheap while the car is in build. I will move along to MS or a piggyback eventually but I do want to try the method I read since I have an RRFPR sitting here for when I get my fuel PSI gauge if the injector upgrade runs lean. I'll report back when I can get to a junkyard and pick up a set of injectors.

doitover · « **Reply #21 on:** August 04, 2012, 09:07:09 PM »

I think some people would be interested in how you had it shortened. I know I would be.

I think you can start the car on the stock setup but I wouldn't drive it around like that for long. Mine pings or knocks ( I have no idea which it is) pretty badly at part throttle with bigger injectors, whatever the fpr with vaccum adjusted pressure, and some random after market chip. The stock ECU will handle closed loop okay.

Quote from: ReSuL;114047

ı had it shortened at last.. ı wanna ask a question.. is it possible to set the kit on the engine and go without changing the injectors and stock ECU?? or do I have to make some certain changes after installing supercharger??

axisofjustice · « **Reply #22 on:** August 04, 2012, 10:19:15 PM »

You can run it, and you can drive it with bypass open/set to 3-4lbs but do not let the AFRs go too lean. I run mine and it doesn't ping too badly with my plugs and my o2 sensor going rich due to age (it's a bad narrowband), I havn't installed my wideband yet but have been forced to drive the car due to family needing my daily. I have never heard detonation actually, which doesn't mean it's not there, I know. It is obviously not properly tuned though, it lacks power and it doesn't feel right.

ReSuL · « **Reply #23 on:** August 06, 2012, 02:32:24 AM »

thank you to all who sincerely answered my questions...

1) how did we shorten it?

I found a lathe/ CNC repairman who accepted to shorten it.. no other repairman accepted by the way.. there is a long shaft that turns two gear on the body of the eaton m90 you know.. and there is one front bearing and one rear bearing and the space between two has no function.. what we did is to shorten this space both on the shaft and on the snout part.. we had it about 4,6 cm shorter and now this is enough to mount it on the engine for me now..

2) the question about running the car with stock ECU? well actually I have a cheap ebay chip which runs better when compared to stock one but I am not sure whether it will be enough not to run lean...

3) another issue is that I am running the car with LPG and I have the opportunity to send more LPG from the LPG injectors.. please correct me if I am mistaken but the idea while tuning the car is that not to make it too lean or rich.. maybe not in the oil but in the LPG I can do this just not the give detonation. I mean not for a perfect tuning..

4) another issue is I havent activated the setup yet.. I just mount it on the engine and havent given the boost into the engine.. the problem is that I do not know or anticipate how much boost it gives now.. any idea to calculate it is welcome..

looking forward for your precious answers..

doitover · « **Reply #24 on:** August 06, 2012, 09:52:49 AM »

Have you checked Eaton's site for info on calculating the boost based on pulley sizes? I'm pretty sure I saw that information there.

ReSuL · « **Reply #25 on:** August 06, 2012, 11:15:16 AM »

no..

but I will immediately... thanks..

edit: now I looked at it but couldnt figured out what they mean..

and it gives a mistake..

axisofjustice · « **Reply #26 on:** August 06, 2012, 03:49:23 PM »

This should get you started...

You need a few measurements, in metric or standard:

-crank pulley diameter
-s/c pulley diameter
-engine size (M42, correct? If so, 1,796 cc)
-valve overlap (not sure where to find M42 stock cam specs)

With this information we can calculate boost and estimated power, but first let's just get boost in PSI:

Variables:
P = pulley ratio, crank pulley diameter divided by s/c pulley diameter.
B = atmospheric pressure of the air outside (standard is 1 bar which equals 14.7 psi).
V = the volume of the blower for one rotation. (Eaton M90 is 1475cc or 90ci)
C = engine capacity in cc (m42 is 1,796 cc), which is divided by 2 since for one rotation a four stroke engine is only half way through each cycle.
L = allowance for boost lost due to valve overlap, ~5% boost loss per 10 degrees of overlap.

Just plug in the numbers and follow the order of operations. I always said college algebra was going to be useless! I do not know your level of education, if you think this is too in depth just get the required measurements and we can work the equation.

ReSuL · « **Reply #27 on:** August 07, 2012, 04:41:14 AM »

well.. I am an English Language Instructor at a University in Turkey and I am pretty good in maths but there are some unknown parts for me... I am giving you the numbers in bold on your answer..

Quote from: axisofjustice;114159

This should get you started...

You need a few measurements, in metric or standard:

-crank pulley diameter 11cm
-s/c pulley diameter we are trying to find this for 0,5 bar
-engine size (M42, correct? If so, 1,796 cc) totally correct
-valve overlap (not sure where to find M42 stock cam specs) I also have no idea about where and how to find it

With this information we can calculate boost and estimated power, but first let's just get boost in PSI:

Variables:
P = pulley ratio, crank pulley diameter divided by s/c pulley diameter.
B = atmospheric pressure of the air outside (standard is 1 bar which equals 14.7 psi).
V = the volume of the blower for one rotation. (Eaton M90 is 1475cc or 90ci)
C = engine capacity in cc (m42 is 1,796 cc), which is divided by 2 since for one rotation a four stroke engine is only half way through each cycle.
L = allowance for boost lost due to valve overlap, ~5% boost loss per 10 degrees of overlap. this is the only thing I can not put on the formula you gave

Just plug in the numbers and follow the order of operations. I always said college algebra was going to be useless! I do not know your level of education, if you think this is too in depth just get the required measurements and we can work the equation.

axisofjustice · « **Reply #28 on:** August 07, 2012, 11:48:55 PM »

I can't find overlap numbers either! I am trying to find them! For now I have chose to use .05 for a 10 degree overlap which is a reasonable expectation for most average engines. You said you were shooting for a half bar of boost.

So, running the formula for a few sizes of pulleys:

estimated pulley size (cm) = approximate boost (psi)

6.75 = 22.5
8.5 = 15.4
9.5 = 12
10 = 11.3
11.25 = 8

Without getting too overzealous with pulley sizes with your Eaton m90 we can get 8 PSI with a 11.25 cm pulley which is good for 209 horspower to the crank, which is about 170 horsepower to the wheels, considering 17% drivetrain loss to be conservative.

ReSuL · « **Reply #29 on:** August 08, 2012, 01:48:08 AM »

perfect information.. thank you very very much.. actually the pulley m90 has on is about 8 cm if I am not mistaken but I will change it no problem..

now next question is.. I have a cheap ebay chip on my car and considering 8 psi, is it a must to tune the car in order not to run it lean?? or is it enough for me since the sensors like O2 will adjust the mixture?? I mean is O2 sensor capable of adjusting the mixture for 8 psi??