High compression and m45 - Boost Forum

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High compression and m45
Saturday, February 04, 2012 6:04 PM
Hello I've searched and searched through this forum for an answer of using higher compression pistons with the m45 roots supercharger for the 2.4 engine.
My thoughts where would running 10.5 compression pistons be okay along with water injection, on the 2.5 pulley? And if so what bore should the pistons be .040, .020, stock?? Also what thickness should the head gasket be? Thanks for the answers in advance hopefully someone will come along.

Re: High compression and m45
Monday, February 06, 2012 10:02 AM
I would have no problem running that kind of compression on the M45.



FU Tuning



Re: High compression and m45
Monday, February 06, 2012 11:47 AM
At what bore would you recommend I run for the pistons at that compression and what gasket thickness?? Correct me if I am wrong but with a thicker gasket does compression go up in the final ratio??
Re: High compression and m45
Monday, February 06, 2012 11:55 AM
A thicker gasket will actually lower your compression ratio... a lot depends on whether you deck the head/block at all and make up for it with gasket thickness.

No real sense massively overboring an LD9 to be honest... 0.020 is just fine and leaves space in case anything happens and you potentially need to re-do the block again.

10.5:1 should be pretty fine with the M45 if that's your goal... your success will be in the tuning and any mods you can do to cool the intake charge to help you. In my opinion a higher CR is a good offset for power rather than putting on a smaller pulley and spinning the charger faster... but we all approach engines differently.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: High compression and m45
Monday, February 06, 2012 12:50 PM
My goal is to keep the m45 on the engine with the safest/streetable compression ratio to accompany the charger.. if I can get 250 at the wheels with the blower off of water cooling and high CR that would be great..
Re: High compression and m45
Monday, February 06, 2012 4:51 PM
Re: High compression and m45
Tuesday, February 07, 2012 8:57 AM
I would love to see 250 at the wheels. Whats the highest dyno for an m45 anyway?



Re: High compression and m45
Tuesday, February 07, 2012 10:43 AM
I'm working on pretty much this build right now.
10.5 stock bore , m45 2.6" pulley, OD pulley. I hope to have a build thread started around march.

I'll be running meth when i get some cash for a kit. Although I'm not that worried about pre-det, its really not that high of a CR and your not pushing that much boost, it'll still help keep the charger cool.

Hope some of that helps.

Quote:

Whats the highest dyno for an m45 anyway?

I think I saw in a thread someone said they where at 230, but there was nothing to prove it.
Re: High compression and m45
Tuesday, February 07, 2012 12:38 PM
-Z Yaaaa- wrote:

bore the block .080 and do 12:1.

Are there any advantages into over boring the block on the 2.4? Wouldn't the CR of 12.1 be overkill with .080 bore along with the m45,or is that really the only option I have to yield 250whp with charger?
Re: High compression and m45
Tuesday, February 07, 2012 1:28 PM
250whp on a built and properly tuned LD9 w M45 is very doable.

I have made 219whp on a stock 134k LD9. Plan to hit the dyno in the very near future to update the numbers since some changes.

I would not overbore unless you have to. Go with a flat top piston. Try and get the compression around 10:1-11:1 and get a very good tune with a 2.5 charger pulley, and a overdriven crank pulley, and some meth/water injection mix. Good flowing 2:5 exhaust, with a header. 250whp should be easy, if tuned properly.



FU Tuning



Re: High compression and m45
Tuesday, February 07, 2012 1:34 PM
eric c wrote:

-Z Yaaaa- wrote:

bore the block .080 and do 12:1.

Are there any advantages into over boring the block on the 2.4? Wouldn't the CR of 12.1 be overkill with .080 bore along with the m45,or is that really the only option I have to yield 250whp with charger?


Brad would recommend you build the engine to within one inch of its life and then run it as hard as you can, lol. It will be the best 42 seconds EVER!

I agree with John's advice above.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...

Re: High compression and m45
Tuesday, February 07, 2012 8:09 PM
lol .080 leaves plenty of meat. its got basically the same cylinder walls as a quad 4 and you can bore a quad .050 no problem.

dont forget... brandon's 551whp motor with over 20psi was bored .040.



Come join us over on the Olds Quad 4 and Twin Cam Facebook group!
Re: High compression and m45
Wednesday, February 08, 2012 9:48 AM
Ok Ill try again. Anyone know what the highest dyno numbers are so far for a m45 setup?



Re: High compression and m45
Wednesday, February 08, 2012 1:24 PM
-Z Yaaaa- wrote:

lol .080 leaves plenty of meat. its got basically the same cylinder walls as a quad 4 and you can bore a quad .050 no problem.

dont forget... brandon's 551whp motor with over 20psi was bored .040.


Oh I know... I was just joking Brad. I am a fan of erring on the side of caution for obvious reasons... lol.

-Chris-


-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: High compression and m45
Wednesday, February 08, 2012 3:14 PM
Craig wrote:

Ok Ill try again. Anyone know what the highest dyno numbers are so far for a m45 setup?


I remember hearing some years back about someone making around 232whp, but I think that was with spray as well.

I know another member made 217whp on a built LD9 and a M45.

I have made 219whp.



FU Tuning



Re: High compression and m45
Wednesday, February 08, 2012 3:42 PM
SweetnessGT wrote:

In my opinion a higher CR is a good offset for power rather than putting on a smaller pulley and spinning the charger faster... but we all approach engines differently.

-Chris-


Thats my thought process too. Especially when youre using a supercharger where the faster you spin the less gain you see due to heat and the limited compressability (is that a word) of any gas. You get that with a turbo too but the extra effort to compress the air isnt taken from the rotation of the engine. The Law of Dimishing Returns is a harsh mistress.

I wonder if Publikdisturbance got his setup done. He was doing something with a higher than normal CR and an M45. I just dont remember what exactly.





Re: High compression and m45
Wednesday, February 08, 2012 8:54 PM
Addicted to meth wrote:

Craig wrote:

Ok Ill try again. Anyone know what the highest dyno numbers are so far for a m45 setup?


I remember hearing some years back about someone making around 232whp, but I think that was with spray as well.

I know another member made 217whp on a built LD9 and a M45.

I have made 219whp.

hmmmm. I was just browsing youtube and found this guy. Read comments. 10.1 compression ratio, cams, blah blah and a 2.4 pulley? Making 226 max to the wheels.

http://www.youtube.com/watch?v=lVN2FtqRPZo&feature=youtube_gdata_player



Re: High compression and m45
Sunday, February 12, 2012 9:12 AM
I have made 219whp.
hmmmm. I was just browsing youtube and found this guy. Read comments. 10.1 compression ratio, cams, blah blah and a 2.4 pulley? Making 226 max to the wheels.

http://www.youtube.com/watch?v=lVN2FtqRPZo&feature=youtube_gdata_player
Well with the upgrades he claims I would assume better numbers, but no cooling with such a small pulley that thing is heat soaked..

Okay now I need to know where to get my pistons I assume Karo over at carcustoms?? Or would this site work since they carry the 10.5 cr pistons?? http://www.importperformanceparts.net/imports/wisecopistons_cavalier.html
Re: High compression and m45
Sunday, February 12, 2012 9:58 AM
My charger was on another loca Z24 before I got it. I also tuned it (street tuned). It has stock cams, same header I have with the 2.5 charger pulley, and stock crank pulley. No meth. IAT's were 190's and guy only made 187whp.

Put it on my car with meth, and cams, and 57mm TB made 208whp. Then later the OD crank pulley, more meth and more tuning 219whp.

My point I do not see that guy making 226 without meth on a 2.4 pulley.



FU Tuning



Re: High compression and m45
Sunday, February 12, 2012 11:01 AM
I bet that car was a blast to dive on the street..



Re: High compression and m45
Sunday, February 12, 2012 6:12 PM
karo made 259whp without a blower...

just saying.



Come join us over on the Olds Quad 4 and Twin Cam Facebook group!

Re: High compression and m45
Sunday, February 12, 2012 7:16 PM
-Z Yaaaa- wrote:

karo made 259whp without a blower...

just saying.


i bet with a blower and a proper tune it would have made more.

just saying.



FU Tuning



Re: High compression and m45
Sunday, February 12, 2012 8:04 PM
Is anyone with an m45 running a racetronix fuel pump?
Re: High compression and m45
Sunday, February 12, 2012 8:13 PM
Addicted to meth wrote:

-Z Yaaaa- wrote:

karo made 259whp without a blower...

just saying.


i bet with a blower and a proper tune it would have made more.

just saying.


it had a blower for a while but not a tune....i bet it was faster without the blower as it sat while i knew it.



Re: High compression and m45
Sunday, February 12, 2012 8:25 PM
N/A2.4 wrote:

Is anyone with an m45 running a racetronix fuel pump?


I am.



FU Tuning



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