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VX Commodore's Eaton M90 with 18 PSI?

Turnerj

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So I have the Eaton M90 on my supercharged VX commodore. Currently I have it running at 12 PSI (intercooled) on my car and I want to push it to around 18 PSI. I have been doing research regarding how much PSI the supercharger can take and I haven't really found an answer that I am happy with. Like, I found posts on various sites talking about this one car that was running 20 PSI on the Eaton M90 but I haven't seen any other mentions of cars running that high on it. At the same time, I have been reading regarding RPM limitations and potential efficiency issues running that high on the Eaton.

I want to know if it is worth the money replacing the Eaton M90 with another supercharger that can handle that sort of pressure or will I be generally fine running that high of a boost on it? How high have others gone on the Eaton M90? Should I am for a boost not so high, maybe 15 PSI?

Thanks
 

0081

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You would need to run about a 65mm pulley on the M90 which would relate to about 18PSI but after you cool the charge you would likely be seeing 15 to 16PSI in the LIM.

The smallest pulley that that I have heard on is a 58mm which would be around 21PSI. (Most people not talk PSI they talk MM as you things like porting will change the PSI reading you will get.) the more used size is 63mm or about 19PSI with a over driven balancer.

The M90 is about at its efficiency at about the stock pulley or the 87mm 10PSI mark. After this you just starting to heat the air and need the cooler. Uncooled the discharge temp will get up to around the 150 degrees C mark. if not a bit more.

I would say you really need to look at A2A cooling for that kind of boost level but others would say the W2A are fine it really comes down to want you want from the car and how you would be driving it.

You can also run a external W2A core using the A2A plate which will give you shorter pipe length and the car will feel quicker down low than the A2A cooler and give you lower temps than the typical W2A coolers. Kind of the best of both worlds.
 

Luke_chargedvt

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I was running 16psi with a W2A setup and it was fine, i would recommend doing some engine work if your going to run that high tho, 16 done some damage after awhile to my engine. Once my engines built I'll be running 19psi, A2A setup on the standard supercharger.
 

Turnerj

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Cheers for the replies.

Already encountered a 3 PSI drop from the supercharger to the manifold (getting 9 PSI at max) relating to the W2A intercooler setup, it is part of the reason I want to go so high in pressure to counter-act the drop.

I managed to find one comment here also mentioning the max efficiency like you said 0081. So perhaps I shouldn't try and stress out the M90 by going that high then if it is less efficient?

To put into perspective why I am doing this, my car makes 188rwkw with it's 12 PSI pulley kit, W2A intercooler, pacemaker extractors, twin 2.5" redback exhaust and high ratio roller rockers. It would be awesome if I could get near 250rwkw without a stroker kit (as it can cost quite a lot) though if that is way out of range without many more major mods, I would settle for ~225rwkw.

Where exactly would I be going from here to make that type of power if I can't squeeze too much more power out of the supercharger?
 

0081

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It will take a lot to get 250RWKW.

You would be looking at about every mod to get there, head porting, charger porting, larger throttle body, cam, A2A cooler, big boost.

From what I have read the M90 is a good blower but it just pumps out some heat when spun hard and you need to control it. you could switch to a whipple or TVS blower but you have the cost to buy them and you will also need some kind of adaptor to bolt it up..
A turbo will likely get you there with less effort but I like the feel of a PD blower for street use.
 

0081

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I was running 16psi with a W2A setup and it was fine, i would recommend doing some engine work if your going to run that high tho, 16 done some damage after awhile to my engine. Once my engines built I'll be running 19psi, A2A setup on the standard supercharger.
Hey mate what kind of damage and what W2A cooler where you running???
 

Decicrate

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@ Turnerj, I still have not found the limit to the amount of power/torque that a L67 with a M90 is capable of.
You first have to understand that trying to force more air down its throat is not always going to increase your power out put, unfortunately there is a bit more to it than that.

To get the power you are chasing you are going to be looking at a nice cam, which will require some head modifications as well as heavier valve springs, double row timing chain, some blower porting, bigger fuel pump, bigger injectors, full tune and the list just keeps going.

In the end the limit is only as big as what you can afford. If you have a big budget, you will get big power.

Currently my L67 with a M90 made 449RWHP or 330RWKW and about 790Nm of torque.

To get to that level, you need to do a fair bit. If you want to see what's involved, click the link in my signature.
 

Turnerj

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Cheers for the advice Decicrate and might I add you have a very nice ride. I figured I would need to go more hardcore on the upgrades at some point to start getting much more power though I have spent quite a bit on the car already and I would only be game to spend up to another $3k on it (give or take a few hundred).

Will definitely look at porting the M90 as well as higher PSI pulley, bigger fuel pump (as my current one is near maxing out anyway), bigger injectors and another tune. I might not reach my 250rwkw goal with my budget but hopefully will still get decent gains.

Is there anything else worth looking at with a limited budget?

Though kind of in the opposite realm to power, I wonder if I should start looking at getting better brakes if I am wanting even more power (though that would likely eat my budget) as I am still running the stock brakes.
 

Decicrate

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If you are going to get a full retune, you could look at changing to E85 fuel, there are some great gains to be had. Trouble is though, its not readily available everywhere yet.
I would also say go a good cam, MACE (site sponsor) have some nice blower cams and all the gear to go with it.
 
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