I am just trying to get a feel for what people have experienced or seen when it comes to built LD9's. I am building my motor this winter but after last weekend I am kinda debating on keeping the s/c. I ran a 14.328 @ 96.15mph and I think with a built engine I should be able to get into the 13's. My build is gonna consist of a port & polished head, cams (looking at the HO cam swap), eagle rods, 9.1 forged pistons bored .20 over, all new valvetrain and possibly oil pump and fuel pump swap. I am kinda thinking I may be able to get some decent gains out of a built engine with the mp45. I love the torque it produces, 175wtq at 2500rpm. Anyways, the reason I am planning on doing 9:1 CR is if the car doesn't get me where I want with the s/c (13's) then I will be going turbo. I'm just trying to get a feeling of what people may think I will gain from head work, cams, and forged internals. I'm not sure if anyone has really done a built engine with the mp45 but I am kinda thinking it may not be a bad project to take on this winter. Anyways, any input would be apprecitated. Just for reference, my car has 190whp and 187wtq right now with a stock motor.
I had a built 2.4 with a M45, but sadly i never had the ability to modify the program until after i sold the S/C. No change to teh program at all and I went from a 14.8 to a 14.2 after the build. I had a very narrow powerband though and needed a lot more RPM/tuning.
definitely go with higher compression. 9:1 is going to lower it.
Familiar Taste of Poison.
z yaaaa wrote:definitely go with higher compression. 9:1 is going to lower it.
Yeah, I think stock is 9.5 or 9.7:1. The reason behind it is that if the s/c doesn't give me what I want then I am going to turbo it. I know ideally 10:1 would be better but its not gonna make that much of a difference and this way I can still turbo it with 9:1. It would be pretty hard pressed to put 12-15psi from a turbo into 10:1 CR. Like mitdr said, he went from a 14.8 to a 14.2 after the build, thats a difference of 6 tenths. Well say for argument sakes I gained an extra 6 tenths on the track that would put me in the range of 13.7 which wouldn't be to shabby. I think with a good set of cams, headwork and some decent valvetrain to rev and make power to 7000rpm I think I can make some power out of the mp45 on the LD9. I think this is what I am going to try since there isn't that much out there for s/c LD9's and it would be interesting to see the potential. I'm still in the process of deciding what I am gonna do for a build but whatever it is, it will be fun to drive.
i think if your going to go through the trouble of pulling your motor to build,then you should build it to turbo it.
Rememeber kids... spell check is your friend
lol yea you need to be specific man... i thought you wanted a sc motor.
9:1 is fine for a turbo motor.
Familiar Taste of Poison.
Right now I'm not sure if I want to stay supercharged or go turbo. I have to buy the parts this fall and probably won't decide which route I'm gonna go until the spring so I think I will built the motor to handle a turbo but if I stay supercharged it will still work. I really like the instant torque of the car being supercharged and I may miss that responsiveness on the street, as the car is mainly a street car it would be nice to have it shine there (although I have put over 50 passes on the car in the last month and a half).
Anyways, I have an idea of what I am gonna do for the majority of the build (pistons, rods, gaskets, head work), but I am still not sure about what is good valvetrain to upgrade to. I have to do some more research but hopefully I will find some good stuff that will work for my car. Still a ways to go before I start buying parts, but hopefully soon I will figure out what I am doing and then get ready for the build and have it ready to tune by april.
Just get OE Forged Pistions.
They Swing both ways.......
Trust me on that.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
^^^ yup. stock compression works well with any type of boost.
you should do 10.5:1's though if you're going to stay sc'd.
its my opinion that we as a community have mis-construed our piston availability and compression ratio. granted no body is ever going to know what the exact CR is unless they cc the head and piston where applicable.
my opinion:
all these wiseco's people have bought over the years (the ones with the dish) are actually straight up 9:1's and not the 9.5:1's a lot claim them to be. a lot of people also claim that flat tops are 10:1 pistons in our engines.
the fact of the matter is NOBODY has higher compression pistons (unless they are bored out) than stock UNLESS they have protrusions (or dome) that come UP and into the combustion chamber. stock compression is 9.5:1 with the stock flat tops is why i bring this up.
(stock bore)
9:1's.... dished and even less if they have valve reliefs.
9.5:1's.... flat tops
10.5:1's.... domed
and beyond that i dont see how it would even be possible. the 10.5:1's have a massive dome and i really dont see how more could be added to increase the compression.
Familiar Taste of Poison.
I have Higher compression pistons...
and there flat tops
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
Thanks for the heads up. I haven't really looked into the Weisco 9:1 CR pistons but that is what I am looking at buying. I have a friend that knows someone that decreased his compression significantly (I can't remember what it was, but I'll try and find out tomorrow) on a stock motor (minus the rebuild) he ran 1 tenth slower than he did stock. If my memory serves me correct (mind u the numerous beers I have had in the last bit may have affected it) he went from a 9.5 to 8:1 CR. I know that 10.5 would be a good setup for a low boost s/c like the mp45 but I'd be upset to rebuild the motor with 10.5:1 and then decide to throw a turbo on it and issues with knock and tuning and have to tear it apart again. Ultimately I want to see 300-350whp next summer and I am almost 100% sure I'm not gonna make it there on the mp45
So it pretty much leaves me to a turbo, but I think I may just leave the s/c on it just to see what it will do. Like I said, my build is still up in the air but I am interested to get some ideas/opinons from people on here. I'll be posting soon to find some more info out.
Taetsch Z-24 wrote:I have Higher compression pistons...
and there flat tops
Chris
hows that? decked the head?
"It's called reading! Top to bottom, left to right... a group of words together is called a sentence. Take Tylenol for any headaches... Midol for any cramps."
Just get Flat Tops.. On the 00 up heads, it makes 9.7:1.
I did it by realizing I hate the oiling of a 2.4.
2.3 FTW.
Everything (performance) is just easier to come by.
I shouldn't say that, Stock Engines make a lot of power? ya, 190 Stock is nice.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
Taetsch Z-24 wrote:Just get Flat Tops.. On the 00 up 96-99 heads, it makes 9.7:1.
fixed.
lol chris. lg0 slugs are a lot larger than 2.4's.
Familiar Taste of Poison.
You will need to figure out if you want to push the S/C'er or go with turbo in order to take full advantage of a build engine.
If you want to go the S/C'er route and get full potential out of it, you need to look for 10:1 final compression ratio, other wise there is not much point in building it for the supercharger.
If you build an engine up and end up going to 9.1 compression, just get rid of the S/C'er and go turbo. Even with a ported head, header, exhaust and intake, you are going to see minimal gains with the S/C'er for the amount of money you will put into the engine. Trust me I have had every kind of set up on the 2.4L you could have... Supercharger, Turbocharged and Twincharged... Its not my first rodeo ahah so to speak.
Also a little info to keep in mind. If you are the kind of person who likes a reliable car and doesnt like to always be fixing or playing around with things than stay with the supercharger. Once you go turbo things start to get a little bit more complicated for most people and expensive VERY fast (been there first hand). I am just putting this out there to maybe try and save you some money. I once poured all my money into my Jbody and got decent results but not that great... Dont get me wrong, the Jbody cars are good first cars and fun to play with (I still have mine packed away in storage) but dont go crazy and blow all your money on it, if your into tuning and modifying cars, wait till you can afford a vehicle that is more of a tuner friendly car.
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
z yaaaa wrote:Taetsch Z-24 wrote:Just get Flat Tops.. On the 00 up 96-99 heads, it makes 9.7:1.
fixed.
lol chris. lg0 slugs are a lot larger than 2.4's.
No, I Am going off of what GM says.
the LG0 pistons may be larger, but the stroke is shorter. and the Head CC is A LOT smaller...
I was saying Run the COMPLETE LG0.....
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
Taetsch Z-24 wrote:z yaaaa wrote:Taetsch Z-24 wrote:Just get Flat Tops.. On the 00 up 96-99 heads, it makes 9.7:1.
fixed.
lol chris. lg0 slugs are a lot larger than 2.4's.
No, I Am going off of what GM says.
the LG0 pistons may be larger, but the stroke is shorter. and the Head CC is A LOT smaller...
I was saying Run the COMPLETE LG0.....
Chris
lol i know what you were saying. i agreed then and agree now.
but what i was trying to get across is you cant compare pistons from an lg0 engine to an ld9. completely different engine. so if flat tops make 10:1 is an lg0 thats good, but they do not in an ld9. not without some things like a 96-99 head and stainless valves being put on top of them anyway.
Familiar Taste of Poison.
I've gotta run out for a bit but I thought I'd post before I left. Wondering how much boost I could run with a turbo with 10:1 CR. I am not entirely sure which turbo I'm gonna go with if I do go turbo but from what I have seen so far it will be something similar to a GT30R (may go ball bearing or journal bearing, not sure yet) but whatever it is it will be similar in specs/size to a GT30. The reason I am asking is because it will increase my CR to help with the small mp45 and if I did go with a turbo wondering if I would be able to run something in the range of 8-12psi.
I would do 10:1. If the charger does not give you enough still go Turbo, and shave the @!#$ out of the head as well.
Edited 1 time(s). Last edited Thursday, September 03, 2009 4:28 PM
FU Tuning
absolutely. the l61 boys have 10:1 and they boost the ish out of those engines.
its fine. you could always back some timing out of the tune if it starts to knock....
Familiar Taste of Poison.
z yaaaa wrote:Taetsch Z-24 wrote:z yaaaa wrote:Taetsch Z-24 wrote:Just get Flat Tops.. On the 00 up 96-99 heads, it makes 9.7:1.
fixed.
lol chris. lg0 slugs are a lot larger than 2.4's.
No, I Am going off of what GM says.
the LG0 pistons may be larger, but the stroke is shorter. and the Head CC is A LOT smaller...
I was saying Run the COMPLETE LG0.....
Chris
lol i know what you were saying. i agreed then and agree now.
but what i was trying to get across is you cant compare pistons from an lg0 engine to an ld9. completely different engine. so if flat tops make 10:1 is an lg0 thats good, but they do not in an ld9. not without some things like a 96-99 head and stainless valves being put on top of them anyway.
To be honest, when building my engine, I didn't give a rats a$$ about the number of the Ratio... Flat tops are by far the most efficient style.
Ergo why I have Karo Make me some for the LG0.....(W41)
Ive said it once, and will once more...
GET FLAT TOPS!...
(cutting the head will help two fold...one higher comp duh, Tow... better cam timing....)
Quote:
Wondering how much boost I could run with a turbo with 10:1 CR. I am not entirely sure which turbo I'm gonna go with if I do go turbo but from what I have seen so far it will be something similar to a GT30R (may go ball bearing or journal bearing, not sure yet)
Once more... MY LG0.. stock 10.1:1.... DISHED pistions...
I have flat tops now....
Ran 14.6 NA....
T3/T04E Garrett Turbo @12 Lbs... (still working with csmith on tuning it to the max of OBD-1... that's proving to be MUCH better then everything out there save GM MEFI-IV)
If I were to build another Quad\Twin cam, And I'm not, I would get forged flat top pistons, Good Rods, the largest valves I can find (anyone try shoving Q4 valves in?) and port the hell out of the ext side.... ya ya, along with the Q4 oiling and the normal @!#$...
YOU HUSH UP THERE JR!
you know to much to tell!
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
thank god we finally have some people talking sense into others on this site. 10:1 or bust. keep that comp up otherwise we are gonna keep looking like pansies to the rest of the sport compact scene. lets make some power boys!!!
I can remember being called an idiot for running 10:1 with my S/C.
Yeah you will regret it....I know I did. I too now wish I had 10:1 pistons instead of these dished 9:1 pistons. But now I have a decked 086 head to compensate the lower compression pistons.
GMR has got nothing on this
