M90 sc
M90 sc
Im almost maxed out with the bolt ons in my 3G and I want more power. I thought I saw a dyi here a while back to retrofit a m90 into the 3g m62 kit but I can't seem to find it. I saw the post on how to do it in a CL but not a 3G TL. I did use the search button but I did not see it. ... I remember this one post had measurements n everything sketched out which the CL post does not have.
I'm planning to do a ZDX intake n TB along with the m90 n boost 9-10 psi. I'm currently at 4 psi even with the high boost pulley and a new bypass valve.
I was about to sell my sc n have my friend do a custom turbo kit but I really love my sc and I already have a turbo car in the garage...
I'm planning to do a ZDX intake n TB along with the m90 n boost 9-10 psi. I'm currently at 4 psi even with the high boost pulley and a new bypass valve.
I was about to sell my sc n have my friend do a custom turbo kit but I really love my sc and I already have a turbo car in the garage...
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Joined: Feb 2006
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From: Space Coast, FL
Im almost maxed out with the bolt ons in my 3G and I want more power. I thought I saw a dyi here a while back to retrofit a m90 into the 3g m62 kit but I can't seem to find it. I saw the post on how to do it in a CL but not a 3G TL. I did use the search button but I did not see it. ... I remember this one post had measurements n everything sketched out which the CL post does not have.
I'm planning to do a ZDX intake n TB along with the m90 n boost 9-10 psi. I'm currently at 4 psi even with the high boost pulley and a new bypass valve.
I was about to sell my sc n have my friend do a custom turbo kit but I really love my sc and I already have a turbo car in the garage...
I'm planning to do a ZDX intake n TB along with the m90 n boost 9-10 psi. I'm currently at 4 psi even with the high boost pulley and a new bypass valve.
I was about to sell my sc n have my friend do a custom turbo kit but I really love my sc and I already have a turbo car in the garage...
If you already have plans for that or a pro tune, then the M90 blower might not even be worth it without an intercooler or Meth injection. The M90 at 9-10PSI is going to make all that air VERY HOT and with the TL's high compression ratio, it's going to cause a LOT of knocking unless you can find a way to cool it down IE an intercooler or Meth injection. I know one member put on the high boost pulley with an intercooler and is making a good amount of power. Or if you don't have the high-boost pulley, invest in that + retuning!
I have pcds jpipe catback high flow cat rdx injectors aasco flywheel p2r clutch HBP tuned on aem meth kit with aem fic6 .... put down 365whp in dynojet and 321 in a mustang dyno at 4.5 maxboost close to redline
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Joined: Feb 2006
Posts: 21,407
Likes: 2,185
From: Space Coast, FL
Like I said, the M90 puts out some hot air compared to the M62 so some form of cooling is necessary like an intercooler. The meth injection might be enough but I don't have much experience with it to know how much cooler the air will be with meth on the M90 blower.
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4.5PSI isn't the High boost pulley! The High Boost pulley should be pushing at least 5-6PSI. It should be about 2.9 inches in diameter while the regular one is 3.2 or so.
Like I said, the M90 puts out some hot air compared to the M62 so some form of cooling is necessary like an intercooler. The meth injection might be enough but I don't have much experience with it to know how much cooler the air will be with meth on the M90 blower.
Like I said, the M90 puts out some hot air compared to the M62 so some form of cooling is necessary like an intercooler. The meth injection might be enough but I don't have much experience with it to know how much cooler the air will be with meth on the M90 blower.
The stock pulley is 3.25"... The HBP is 3" in diameter which I got straight from CT AND which has NEVER been tested by comptech themselves!!! You can call them and ask them yourself if you don't believe me. .. I have only seen blips of 5 psi very few times
The m90 does not produce hotter air than the m90. It takes the m90 a lot less rpms to produce the same psi hence lower air temps. The m62 is almost maxed out at 7 psi and going out of efficiency at 8-9 psi producing almost only hot air. In the other hand it will take the m90 around 12psi to achieve the same state n start producing only hot air. Larger displacement sc does not require 17, 000 rpms to build 8-9 psi of boost....
He wants waaaaay too much money for it. It is a custom part but you can get a turbo kit for that money .... actually a local shop/friend of mine does custom work and he is willing to put a kit together for me for only $2500. But I don't want to go through all the trouble of uninstalling my sc selling it, n putting it back to stock just to fund the kit. Besides I love the sc.
Senior Moderator
Joined: Feb 2006
Posts: 21,407
Likes: 2,185
From: Space Coast, FL
Have you ever modified a TL? RESEARCH does not equal experience....
The stock pulley is 3.25"... The HBP is 3" in diameter which I got straight from CT AND which has NEVER been tested by comptech themselves!!! You can call them and ask them yourself if you don't believe me. .. I have only seen blips of 5 psi very few times
The m90 does not produce hotter air than the m90. It takes the m90 a lot less rpms to produce the same psi hence lower air temps. The m62 is almost maxed out at 7 psi and going out of efficiency at 8-9 psi producing almost only hot air. In the other hand it will take the m90 around 12psi to achieve the same state n start producing only hot air. Larger displacement sc does not require 17, 000 rpms to build 8-9 psi of boost....
The stock pulley is 3.25"... The HBP is 3" in diameter which I got straight from CT AND which has NEVER been tested by comptech themselves!!! You can call them and ask them yourself if you don't believe me. .. I have only seen blips of 5 psi very few times
The m90 does not produce hotter air than the m90. It takes the m90 a lot less rpms to produce the same psi hence lower air temps. The m62 is almost maxed out at 7 psi and going out of efficiency at 8-9 psi producing almost only hot air. In the other hand it will take the m90 around 12psi to achieve the same state n start producing only hot air. Larger displacement sc does not require 17, 000 rpms to build 8-9 psi of boost....
The orignal guys from comptech, who created the kit (I believe his name was nate) were really good and to protect themselves (the company) had to tell folks that they weren't using the High boost pulley and didn't recommend it. The reason, the comptech ACM was pretty much the best they could do with the R&D budget they got and using the HBP on an unmodified car otherwise would end up in a blown motor. The ACM originally was okay, it had a TON of surging and made the car horrible to drive when it was hot and humid outside (welcome to FL weather EVERY DAY in the summer).
You know how I know this? I helped a friend install the S/C kit on his TL in Dec 2006. On the install I did we got 4.5PSI on the boost gauge on the FIRST run we did. After driving around for a month he wanted more power. Don't believe me, why not look into the threads back from 2006 & 2007 where other folks were getting 4.5PSI off the stock pulley including some folks who were pioneers in getting parts made for the TL. Maybe your S/C has a broken spring or needs some maintenance work.
We tried to dabble in the HBP but were told "off the books" by them that unless we could figure out how to tune it, which Hondata and Comptech couldn't do at that point then we should invest the money in building a stronger motor. We later learned when the hot weather came in march what they meant when the car was driving horribly in traffic.
As far as efficiency, you should read atrain's posts which I bookmarked and found helpful when we were looking for a solution for more power back in 2007:
nicepeta,
More boost does not equal more power. Boost is made when you flow air through a restriction. The more boost you have on the guage, the more air is stacking up and not being used.
You can only pack some much air and fuel into the combustion chambers. Keep in mind what determines power outout of ANY gasoline engine is how efficiently it burns fuel. Air is a limiting factor in power production.
Speaking Comptech supercharger only it is based off an Eaton M62 supercharger and no intercooler. Adiabatic efficiency of the Eaton M62 is around 65% at 4-5 psi. Most Eaton's postive displacement hybrid roots blowers work like this. They offer tons of air flow down low with little boost.
Spin the blower faster and create more boost and you start to leave the efficiency range. At 9-psi and 18,000 rpm the M90 turns towards the 55% range. 55% air and the rest is unwanted HEAT. At 12-psi it is around 50% and working against you.
More heat in the air charge means less oxygen is present. The overall potential to make power is reduced. If air is denser it packs more oxygen which can be mixed with the right amount of fuel.
The second whammy is more heat means more spark resistance or the reduction of the ability for the spark to ignite the air fuel mixture. Since electricity is lazy it flows to the path of less resistance. Many supercharged engines with stock ignitions have blown the spark out under boost (as little as 6-psi). I have seen many cars with distributorless ignitions lose power from spark blow out under boost.
The easy cure is to reduce the gap on the spark plugs.
Moving on, since more boost changes the air charge compression ratio (not the static compression ratio) it always means you will be more knock constrained. This means the actual spark advance must be retarded or spark is pulled (reduced) to avoid knock.
In all my testing the rule of thumb is, 1 degree of spark on a supercharged car is worth 4-5 HP and 8-10 lb.-ft. of torque. Pull back 4 degrees of spark but add 2 psi of boost and what have you gained? You lost 18 HP and 36 lb.-ft. of torque.
Can more boost increase power output? Yes and no.
If it were always yes, then you could add 100 psi and make "X" amount of power right? Again, only so much air/fuel can be compressed into the combustion chamber and cylinders.
The key to adding more boost is to make sure you are still within the range of adiabatic efficiency of the supercharger. Cooling the air charge is the best way to add more boost but wait there is another thought.
I have seen cars with and without intercoolers and the bottom line is the cars with I/C units always make more power than the cars without I/C units. Longevity is also increased with an intercooler as it keeps you less knock constrained.
Adding an intercooler (water-to-air) to the Eaton M62 would drop the discharge temps anywhere from 50-70 degrees F. on a 80 degree ambient day. Boost would drop off slightly, but more power would be available since you can add more spark timing without knocking.
You don't want boost, you want cool dense air flow and lot's of it. The ideal hybrid roots blower spins the snot out of the supercharger but makes little to no boost and lots of air flow.
A-Train
More boost does not equal more power. Boost is made when you flow air through a restriction. The more boost you have on the guage, the more air is stacking up and not being used.
You can only pack some much air and fuel into the combustion chambers. Keep in mind what determines power outout of ANY gasoline engine is how efficiently it burns fuel. Air is a limiting factor in power production.
Speaking Comptech supercharger only it is based off an Eaton M62 supercharger and no intercooler. Adiabatic efficiency of the Eaton M62 is around 65% at 4-5 psi. Most Eaton's postive displacement hybrid roots blowers work like this. They offer tons of air flow down low with little boost.
Spin the blower faster and create more boost and you start to leave the efficiency range. At 9-psi and 18,000 rpm the M90 turns towards the 55% range. 55% air and the rest is unwanted HEAT. At 12-psi it is around 50% and working against you.
More heat in the air charge means less oxygen is present. The overall potential to make power is reduced. If air is denser it packs more oxygen which can be mixed with the right amount of fuel.
The second whammy is more heat means more spark resistance or the reduction of the ability for the spark to ignite the air fuel mixture. Since electricity is lazy it flows to the path of less resistance. Many supercharged engines with stock ignitions have blown the spark out under boost (as little as 6-psi). I have seen many cars with distributorless ignitions lose power from spark blow out under boost.
The easy cure is to reduce the gap on the spark plugs.
Moving on, since more boost changes the air charge compression ratio (not the static compression ratio) it always means you will be more knock constrained. This means the actual spark advance must be retarded or spark is pulled (reduced) to avoid knock.
In all my testing the rule of thumb is, 1 degree of spark on a supercharged car is worth 4-5 HP and 8-10 lb.-ft. of torque. Pull back 4 degrees of spark but add 2 psi of boost and what have you gained? You lost 18 HP and 36 lb.-ft. of torque.
Can more boost increase power output? Yes and no.
If it were always yes, then you could add 100 psi and make "X" amount of power right? Again, only so much air/fuel can be compressed into the combustion chamber and cylinders.
The key to adding more boost is to make sure you are still within the range of adiabatic efficiency of the supercharger. Cooling the air charge is the best way to add more boost but wait there is another thought.
I have seen cars with and without intercoolers and the bottom line is the cars with I/C units always make more power than the cars without I/C units. Longevity is also increased with an intercooler as it keeps you less knock constrained.
Adding an intercooler (water-to-air) to the Eaton M62 would drop the discharge temps anywhere from 50-70 degrees F. on a 80 degree ambient day. Boost would drop off slightly, but more power would be available since you can add more spark timing without knocking.
You don't want boost, you want cool dense air flow and lot's of it. The ideal hybrid roots blower spins the snot out of the supercharger but makes little to no boost and lots of air flow.
A-Train
You need to understand with more boost come more heat! The M90 blower will add more boost at lower RPM's, but will require more HP to spin and as well will produce hotter temps since it's compressing more air. Have you ever heard of thing called the ideal gas law or PV=NRT?
Basically a supercharger increases P (Pressure) and blows air into a constant volume (V). By BASIC math one of the other numbers on the other side should increase. N is the amount of substance (related to the PSI/Volume) and R is constant. That means T (temperature) is the only variable that is going to increase rapidly.
Even though the M90 is more efficient, the higher HP needed to drive it and the ADDITIONAL BOOST it will give you is going to give you VERY HOT AIR which needs to be cooled. Don't believe me? Look at AckTL05's Black Market post where he has the "liquid to air after cooler" for sale along with his S/C with the m90 & that's why it's 4K for the kit, because he was smart, listened to people who knew what would happen and researched and built his setup PROPERLY:
https://acurazine.com/forums/car-parts-sale-361/all-you-s-c-turbo-guys-custom-875399/
Me and my buddy went though ALL of this, looking into RSX injectors, custom injectors, a custom FIC and bumper, and the M90 & M112 blowers. You want to know our findings:
1. it cost a TON of money to do and 2. was a LOT of work and required a LOT of time to get right.
This was before the advent of the AEM FIC piggyback and the new Hondata reflash's and tuning that's available. Now that's it available it's much more attainable but you still have hurdles to overcome like heat, fitment and simply getting the tuning right without getting the fuel too rich to keep the motor from blowing at full boost and High RPM's or simply combating the knock you will be getting and the strain on the factory parts (pistons, rods, pins, etc) which will eventually need to be replaced with stronger ones.
You should check your facts and knowledge, research or practical, before you try to call someone out, especially a moderator.
EDIT: I just read you last post and you want to know something funny, the reason the M90 has only been done by 1 person so far is the cost of putting it together. The turbo kit is much better bang for the buck vs an S/C setup on the TL.
Last edited by csmeance; Dec 29, 2012 at 11:04 PM.
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