I wanted to gather some opinions from those with experience in boost. I plan to boost my high compression engine with at least 5 psi of boost once I get my numbers N/A on a dyno.
I am unsure or exact on my final compression but it looks close to 12:1 or so due to a decked 086 head on a 2.4.
Will 93 octane gas work fine? Im just tired of having a big body OLDSMOBILE running all motor....if it was a j-body that would be a different story.
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That is a little high but as long as it was low boost and had a good tune it would be ok. Higher compression is ok for lower boost levels but the tune has to be spot on.
How are you gona make the m45 work on a 2.3 head?
I was hoping to cut off the flange and weld on a 2.3 flange. Unless there is more involved.
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No you would probably be able to do that, just have to cap off the extra vacume nipple after the tb that goes to the pcv port in the ld9 flange. Plus you have an n-body soo theres more space in the engine bay. Maybe even use a phenolic port adapter, which would help with cooling.
Im looking to give it a shot soon. I mean I noticed alot of members here lack big numbers with there turbo setups and superchargers. And I see honda's with simliar mods but do not yield to apply high compression thus allowing bigger numbers.
What nipple do you speak of after the throttle body?
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Yea you can make more power with higher compression and less boost, just have to be more careful with the tune.
Theres a nipple on the sc after the tb flange that goes to the nipple on the bottom of the manifold flange for the pcv port. The vacume nipple is post tb but pre sc rotors soo your not boosting the crankcase.
id make sure and run a water/meth injection set up , and make sure you keep a eye on knock , being your at or near 12 to 1 , 93 would be the minimum id run , and 100 with out water/meth
and there is a high compression motor here with a s/c on it and high boost , but it is still in the tuning stages and i just brought back the header and 3" exhaust up to the rear axle for him from cali
Better get this flange professionally welded... you gotta do a better job than was done to that H.O manifold, esp with the slag inside the runners.
And I'm not trying to say that to knock you, just to give you sound advice. Go get it professionally TIG welded, you'll have great flow.
And yeah... high comp plus boost is doable... 12:1 + 5 psi of boost isn't the end of the world, easily manageable so long as it's tuned 100% properly. Don't get greedy with the boost, though.
If I was you, for extra safety, I'd def take the advice above and install meth.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
I was planning to run an intercooler and maybe maybe meth. I just dont know how meth works. Do I need to be refilling it constantly or is it like coolant.
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I thought you had the 9-1 wiescos in there....that would work out to roughly 10.5-1. A stock 2.4 with the factory flat tops yield a 11.37-compression ratio. If my math is right you will be golden with boost. I plan on throwing boost at mine to after I get it running N/A and I essentially have the same build as you save for the cams. Hope that helps.
I do plan to get it welded better than that manifold. I just got it done for free from a friend. I did not like the inside runners at all. Heck he did a terrible job on my OBX header to 2.3 flange so now I need to get it removed and done again. So thats stopping me right now along with a good tune to get some numbers out of this build.
Again I was unsure on the final compression Cory...but remember I do have a decked 086 head.
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Mine is also decked, which i didnt take into accout lol. I still cant see it raising to more than 11-1 at most. Either way the more compression the more fun especially with some boost.
CraiGM wrote:DOHC_tuner wrote:I was planning to run an intercooler
Might I ask, HOW?
Yeah never mind I noticed this can not work on the M45....would be nice though to help keep my IAT's down.
Right now I am very worried about the IAT's.
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you might wanna think about doing the M62 from the LSJ and running a intercooler , it would give you the bst all around performance and allow for alot higher boost levels
though i would count on getting a 1 5/8 or 3/4" primary tube header , and full 2 1/2" exhaust if not 3"
meth would require filling it up every so often
I want to do the M62 but im not looking for anymore boost than 5 psi since im running with high compression. If I find a good deal on one I will take it but can the manifold be altered the same way just by cutting off the flange and welding on a 2.3 one?
Plus I'd see it more cost effective to do the M45 since its cheaper and easier to bolt up along with the fact all I need is at least 5 psi. Keep the help coming I need it!
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im assuming you wanna do this for more power , why not go for gold instead of the booby prize , lol
i know alot of high compression cars out there running high boost levels , GM was running 14 to 1 and 50+psi on the eco drag cars , so 12 to 1 and 10psi would be fine , its just all in the tune and how far you wanna go
my friends s/f is around 11 to 1 , and the s/c with the over drive crank pulley was making 13psi on his stock motor
I just want to stay safe with 93 octane....no race gas.....Im building a street driveable car yet still with top horses when needed. But i'll see if I can get my hands on a M62. Heck I found a M90 at the junkyard for 40 bucks.
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Be careful. The bigger blower may be more efficient, but your largest single challenge will be controlling knock in the midrange, especially with sudden load at throttle tip-in, say 2500-3500 RPM. That's where the high compression will really hit against boost, and the bigger blower may exacerbate this by its greater airflow. Addtionally, I don't know if you could get a large enough pulley to get the bigger blower all the way down to 5 PSI boost. As a final point, do keep in mind that the poorer efficiency of the smaller blower will be less of a concern at such a low boost level. The real heat comes at higher boost.
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
Not sure if anyone is running a M90 on the 2.4, correct me if someone is (I just haven't seen it). The MP62 does have more potential than the mp45 as it can be intercooled and it can push more cfm. But if 5psi is all your looking for the mp45 will get you there and with a good meth kit it will keep your IAT's pretty good. I'm running 7-8psi with mine and meth and the temp of the s/c is much lower than it was with the 2.7" pulley and no meth (went from a 2.7-2.6" pulley and added meth). I think there would be some good numbers to be had with a mp45 on high compression with some decent engine mods. The one thing I love about the s/c is how reliable it is. One weekend I drove the car 1000kms raced all weekend and had not one problem and beat a fair number of decent cars. I'm kinda sad to be getting rid of my s/c over the winter cause I love the whine
And if you start with 5psi (which would be the stock 2.8" pulley) and you have no signs of knock you can always throw a smaller pulley and pick up some more whp. I went from a 2.7-2.6" pulley and gained 7 or 8whp and equal amount of torque. I'll be selling my mp45 kit in the next little while once the motor is taken out of the car to get rebuilt.
Whatever you choose for boost even a low amount can make the car a lot of fun to drive. I think I have one of the lower whp in the s/c LD9 and I can still run low 14's so it is definately quicker than stock.
the guy that has the northstar use to have the M90 on his 2.4
chris said don't get greedy with the boost thats not and issue on an M45 you could probably blow more air into that engine with a Mcds straw the the M45 will blow
well maybe no but 12:1 with the M45 shouldn't be an issue maybe get a methanol injection kit aswell to help you out with the 93+ octane
JBO since July 30, 2001
Matthew Jollymore wrote:Not sure if anyone is running a M90 on the 2.4, correct me if someone is (I just haven't seen it). The MP62 does have more potential than the mp45 as it can be intercooled and it can push more cfm. But if 5psi is all your looking for the mp45 will get you there and with a good meth kit it will keep your IAT's pretty good. I'm running 7-8psi with mine and meth and the temp of the s/c is much lower than it was with the 2.7" pulley and no meth (went from a 2.7-2.6" pulley and added meth). I think there would be some good numbers to be had with a mp45 on high compression with some decent engine mods. The one thing I love about the s/c is how reliable it is. One weekend I drove the car 1000kms raced all weekend and had not one problem and beat a fair number of decent cars. I'm kinda sad to be getting rid of my s/c over the winter cause I love the whine
And if you start with 5psi (which would be the stock 2.8" pulley) and you have no signs of knock you can always throw a smaller pulley and pick up some more whp. I went from a 2.7-2.6" pulley and gained 7 or 8whp and equal amount of torque. I'll be selling my mp45 kit in the next little while once the motor is taken out of the car to get rebuilt.
Whatever you choose for boost even a low amount can make the car a lot of fun to drive. I think I have one of the lower whp in the s/c LD9 and I can still run low 14's so it is definately quicker than stock.
How much are you looking to get for your used SC kit?
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I am really worried about the advice some of you guys are giving the OP!
For starters the car is a 99 so running the GM reflash is out. That would not be a big deal except this will mean he has no way to retard timing for boost. This is an even bigger deal in his aplication then most because keeping knock and possible detonation under control is even more important since this setup will be prone to it. We don't even know how you plan to tune this.
Next up I just want to remind you 93 octane is not available everywhere. Nor do I think 93 octane alone will be enough to prevent knock in this setup. If you go through with this idea alky injection would be a must have both to cool the M45 and to prevent knock.
I understand you are using an 086 head. This means you will need an adapter. I would highly reccomend you get one made out of a phenolic material rather than metal. You really ought to take advantage of having the room to put a spacer between the head and MP45 or whatever metal intake manifold you go with. On the Jbody cars there simply is not enough room to put a spacer between the head and M45. The blower would hit the radiator support.
If you do go with the MP45 I would not go any smaller than the stock size pulley. A smaller pulley will create more knock and higher IAT's
M62 Or MP62??? You have got to be freaking kidding! From reading your above posts I don't think you know @!#$ about what that involves or even the difference between an M62 and an MP62 and what vehicles which one can be found on! The m62 and MP62 do unbolt from their manifold. Unlike the GM Performance Parts MP45 kit supercharger where the MP62 is cast as part of the manifold. Just being able to buy xyz supercharger from the junkyard for cheap is worthless without the manifold to bolt it to the engine.
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
Smoothflowpulleys can make u custom sized pulleys for the m45 or m62. Go the cost effective route. High comp+boost=high cylinder temps=higher chance of knock. So ur main concern is temps. U want to keep cylinder temps down. Things I would recommend.
-A bigger blower will work less to make 5psi. So a m62>m45. And u'll prob need a 3.5" pulley for the m62 to make 5-6psi
-intercooling is a plus, keeps ur iat's down, which keep ur cylinder temps down too
-93octane gas will help too as it has more knock resistance than 91 or 87
-colder spark plugs help too. Go 1-2steps colder
-tuning is the biggest part, need to run a good tune
Got to get back to work(gm customer service) so I'll finish later.
