it all depends on how your engine flows the air. the more restricting the heads, intake etc the more boost it will build than with a engine with better flowing heads, intake etc on the same pulley.

put it this way, on a stock engine and stock pulley say it makes 7psi (im guessing at the psi number i have no idea lol) now you port the heads and intake, open up the exhaust, install headers, get an intake etc and still run the stock pulley it may only produce 5psi (guessing psi number again) do to the engine flowing better so the air isnt backing up enough to build as much boost....

 

It is impossible to say, as you haven't included nearly enough information. What is the M90 blowing into? A stock L67? An L36? A cammed L67? etc etc.

Sure, as is any supercharger you like. A custom adapter plate can be made for any supercharger. The only downside is- I don't know of any M112s that don't have the RWD U curved intake. There used to be adapters made for an MP112, and they still float around used every now and then.

Again, you left out 99% of the information. Is the M112 on a 4.6L Cobra V8, is it on a cammed, fully ported L67, is it on a stock L32, etc?


Why not? If it is a warranty issue, I wouldn't worry about it. The only thing the warranty wouldn't cover are those parts you have modified or if the damage is caused by something you modified. Add a turbo kit to the car- and if the windshield wipers quit working, they still have to fix them (unless you goofed up the wiring somehow). If you add a turbo kit to your car, and blow the transmission- they obviously won't fix that now, or after the warranty is up.

Yes, a turbocharger runs off exhaust gasses and a supercharger runs off of some kind of mechanical coupling to the engine (ie belt driven).


LOL, what? I think someone has been misleading you. Boost doesn't make a difference if it is on a 'tuner car' or a muscle car- it is the same thing either way. An internal combustion engine is an internal combustion engine- the turbo doesn't know what kind of car it is in.

Also, a 'set size turbo' pushes 16 psi boost. Why? Because that is what the wastegate is set for. Once you reach 16 psi (gauge pressure, not absolute) in the manifold on this hypothetical setup- the wastegate will open partially, to allow some exhaust gas to bypass the hot side of the turbo, and to maintain 16 psi in the manifold.

If you place this same turbo on another engine of relatively the same size and characteristics (lets say on a 2.0L I4 instead of a 1.8L I4)- it can still be set to run the same 16 psi via the wastegate. The only time this turbo would exceed 16 psi- is if it were put on an engine so small, that the same size wastegate could not bypass enough exhaust gas to keep the airflow levels low enough. The only time this turbo would not be able to hit 16 psi- is if it were put on an engine so large, that it could not flow sufficient air to reach 16 psi on said engine (we're ignoring RPM here, and saying all these engines run the same RPM).

This is not at all how a typical, positive displacement supercharger works.

You're not going to find this from anybody because again, you're missing 99% of the data. If you are really interested in finding out exactly- there is engine simulation software. You plug in all the variables for your engine, the temperature, etc, and you would take into account all the mods your vehicle has done. Then you would enter all of the engineering data for the supercharger- and then you would calculate supercharger RPM (based off of crank pulley size vs supercharger pulley size)- and it would be able to roughly approximate boost at each given supercharger rpm/engine rpm. The other way to find out would be to find someone local who has the exact engine setup you plan to run, and have them install a gauge on their car. That way you've got the same temperature, altitude, etc.


LoL again. Your primary goal for your engine is 18 psi?

That should be pretty easy, and relatively inexpensive. You shouldn't port the heads, install an aftermarket camshaft, or anything else that would make the engine breathe better. This would all lower your manifold psi. I don't think 18 psi is possible on a stock engine without knocking- so you'd likely have to install an intercooler to keep knock away- and then just keep dropping pullies until you reach your 18 psi goal. The engine isn't going to make very good power, but at least you will hit your 18 psi goal pretty easily.

Any supercharger can be made to fit an L67 if you have enough money and resources. All it takes is an adapter plate to bolt it up, which can be made by any competent machine shop, and could be designed by numerous performance shops across the country.

I guess my real question here is- why are you trying to swap superchargers already? Is your stock one maxed out as far as mods go? M90's have made over 400 whp, if you're shooting for beyond that- maybe you should be thinking about a turbo instead. Besides, the 18 psi goal can happen on an M90.

Obviously- every supercharger as a parasitic loss. If you are mechanically spinning anything to move air- a CSC, roots blower, twin screw, or even a simple fan- you have parasitic loss. If you want to stick with a supercharger, that's life, and you'll have to live with it.

The bigger the supercharger's spinning parts (ie m112 vs m90), the more hp it takes to spin. The faster you spin it, the more air you move, the more power it takes to spin.

Equivalent in what way? Yes they are both positive displacement superchargers- but I wouldn't say they are the same. The TVS series has a lot of engineering advances built in. It shouldn't be too hard to find one- I'd imagine if you google enough, you could find one used.

You probably won't either- there are a ton of variables at play here. Just comparing the head units alone doesn't give the whole picture, it is how they perform when installed on X engine combination that matters most.

That was easy, why not buy it from magnuson then if that is the one you want?


On a stock engine, with just an IC or leaded race gas to fight knock- sure, maybe even a 3.0 might do it on a gen 3 m90.


In my honest opinion- forget about the boost number, forget about buying a boost gauge- it is a waste of money on a supercharged setup. What are you going to do with the information it tells you? You can't adjust boost on the fly (without dumping the BBV), so it is useless.

What you need to get a gauge for is knock (like an aeroforce). Run the smallest pulley you can without knock, and with decent spark timing- and be done with it.


I really think you need to change your approach. Forget about swapping superchargers to something non-M90 unless you've just got a bunch of money you want to blow. Instead of setting some holy grail boost number- forget that, and get a power goal in mind. Then, we can tell you what kind of combination to run to hit that goal (or if it is even possible). I think you will be a lot happier in the end.

 

Here is the setup I was going to run. A 4.2 stroker kit with ceramic coated pistons. 8.2:1 compression with a slight mill on the heads and block to bump it to 8.5:1 compression. Fully ported and polished heads with ceramic coated valves and beef them up to handle the load I am going to put on it (also dont know if it works on chevys but on mopars if you cut the valves and the port it sits on to 28* it improves flow on bottom end but you lose some high end power at high RMP). Aftermarket Camshaft Have not decided which. Headers. Worked exhaust with deleted u bend ect. Ported and matched intake milled for IC room and better flow. IC for roots blower from ZZP. Not the short stack. Worked M90 housing polished and ported and a pulley drop. Northstar throttle body. Cooler T stat. Hotter plugs. Billet fuel rails for more flow if I need it. bigger injectors. And if I can find it a pulley kit for the L67. Of course this will be bolted to a built Trany. And thats all I can think of off the top of my head.

My friend had his del sole built and his turbos were set at 20psi he made +500hp. He started blowing hoses so he dropped it 13psi and still made 350 ish same small 4 banger. It was a completely built engine. He was the one who told me to try for 18 psi boost for my engine build. Its not like I dont know about engines I just dont know about boosted engines and some of the new tech. And my comment about R1900 being the same is that the R1900 is eaton's TVST replacement for the M90. It fills the supercharger spot that the M90 had like the R2300 fills the spot for the M112. And Magnuson superchargers are around $8k for the IC R2300 setup and that would probably equal the rest of the engines build or more. And as i said befor I am building from the bottom up, so I have not maxed out the M90 but I was looking for the best option to use. I dont want to get a few grand into a build just so say ah damn I should have bought the Novi instead.

 

I'd certainly scrap that idea, it's another waste of money. I've not seen any records set by a 4.2 stroker setup- even that guy with the stroker and the 3.3 whipple was only making 400s whp IIRC. Also, strength isn't a factor either- no one is breaking stock cranks from power. If you stick with the M90- you'll never come close to the power level needed to destroy the bottom end.

Also, if you stick with an M90, you don't want to drop to lower compression. Many of the record M90 builds were done with higher compression. It's silly to spend that kind of money, only to end up back at stock L67 compression. If you're dead set on 8.5:1, get a stock L67 bottom end, and be done with it- you'll be glad in the long run. Put that extra $4k+ into mods that actually make power, or put that money in the bank.

You also don't want to be milling so much off the heads to get .3 more compression. You actually don't really want to mill the heads much at all. If the heads are warped, just take off enough to get them straight, and leave it. There is enough flex there as it is without adding extra head bolts- you don't want to make it worse.

That would be the opposite of what you'd want on these engines. You want to gain upper RPM flow and power because the engines were designed to be low RPM torque monsters, especially with the S/C. Adding more at lower rpm doesn't help because you won't be able to hook down there anyways- which is why turbo lag isn't really a problem. You can't hook full boost on street tires from a dead stop anyways.

Sounds like a decent setup- potentially a full on M90 build. This does beg the question though- why not a turbo kit? This full on M90 build will get you to a max of just about 400 whp depending what heads/cam, etc- (probably more realistically in the 350 whp range) but for less money on a turbo kit, you could have more power. Just a thought. There is a reason why a lot of the full build M90 guys switched over to turbos (the same reason why a lot of NA guys switch over to M90s- on a full out build, you've got a ton of money sunk into, and are still getting whacked on by relatively mild M90 setups)

That doesn't make any sense. If the engine was built to handle the airflow of that turbo at 20 psi, why restrict it to 13? Hoses blowing off isn't big a problem, especially for someone with a 'fully build engine'- there are plenty of people out there running WAY more than 20 psi and they don't have problems keeping hoses on. There are tricks to help keep the hoses attached- special clamps, a lip where the hose attaches to, etc. I suspect there is a lot more to the story here.

As mentioned before- that's just a silly number. If you want to listen to him- get an IC or some leaded race gas- stick a 3.0 or 2.8 or something on a stock engine, and you'll hit your 18 psi. Forget all of the other mods as they just lower the boost. Won't make good power, but who cares- you'll get the 18 psi.

On top of that- why 18, would 19 make too much power? lol

Saying to shoot for x boost number is just plain silly, especially on an M90 setup. If you do all the mods you say you are, put some real heads on there, and a good sized cam- I don't know if you'll even be able to hit 18 psi with an M90. So if you made 375whp, but only had 15 psi- you'd be disappointed? I think you get me point about trying to quote boost numbers- it just doesn't make any sense.



With 3800s, you don't start at the bottom though- you leave the bottom alone, and build it from the heads up. If you feel like throwing a bunch of money away- that's fine, but just know that you're not gaining anything from it. I'm not sure where the misconception comes from that the 3800's need a built bottom end.

If you look at your horsepower goal instead- it is pretty well mapped out what an M90 can do. If you're trying to make 500 whp, it's not going to happen with an M90. If you're trying to make 400 whp with a mild cam, it's not going to happen with an M90. There shouldn't be any surprises, as M90 builds have been done to death- just pick a path that has already been done and proven, and go for it- and based off what others have made power wise, you should be right in the ballpark with a good tune.

As to the statement quoted above- when you end up with $10k in this engine and trans as you're talking about, and you're still sub 400 whp, I'd bet you're going to say 'I should have bought a turbo instead'. Nothing sucks more than getting beat by someone who has less money and less work into their car- and theirs is more streetable and gets better gas mileage. If you're friend's del sol really makes 350 whp, and is capable of 500 whp- I'd bet he'll be able to beat you at any power level as long as you have an M90- assuming he can actually get the car to hook due to the weight difference.

 

you have the most knowledge anyone has ever gave on here

 

Ok. I guesse I will just have to swap to a turbo then. The Stroker was because with mopar blocks they usually have a short stroke and putting in a 4" crank yeilds massive power gains. Turns a 340 into a 416 and it is a monster. I have always built motors from the botom up that way no matter how crazy I get down the road with whats going on up to I will never need to redue whats down low. I blew an old 273 out because I redid the top end and the bottom couldn't take the extra compression. The mill was not going to be to crazy max mill on our block and heads is around .030 each if you do max it boosts compression by .25:1 each. so doing a half mill .015 I would still have three ish more rebuilds and would have a garantee my my seals were tight. Ford taurus my friend had he did not mill the heads after the rebuild and never could get them to seal he had to strip it down mill and put it back on. I went to tech school for auto mechanics in highschool so I worked on alot of my friends cars. Wasn't very good at it made alot of mistakes so never kept going. And the 18 psi was for a built engine I thought that would be implied. He estimated that with a boosted 18psi on a built engine that all the power I would be able to get to the road. Around 550-600 crank hp. I assume he told me that because he couldnt get his del sol to grab. The 28* backcut is out then. 600 crank is what I would be shooting for.

 

Ignoring some variables, the point behind a stroker is to increase engine size. This in turn increases airflow, which increases fuel flow, which equates to more power. So your stock 3.8L engine takes in 3.8L of air every 2 full revolutions (since its a 4 stroke)- so a 4.2L stroker would take in 0.4L more air per full cycle (obviously we're ignoring the fact that the engine wouldn't actually take in as much air as it's displacement).

Now, lets say you have a 3.4" pulley on the M90, with a 6.9" crank pulley. That would mean for every 1 revolution of the engine, the s/c (which displaces 90 cubic inches per revolution) would spin 2.02 revolutions. Since it is a 4 stroke engine, you would double the number of engine revolutions- and that would give you 4.04 revolutions of the supercharger per 1 engine cycle. Multiply that by 90 and you get 363.6 cubic inches output by the supercharger per complete engine cycle (we'll assume the engine uses all of the air given to it).

Now, take out 5 bolts, and slap on a 3.2" pulley, and you now get 2.16 SC revolutions per crank rev, or 4.32 SC revolutions per engine cycle. Multiplied by 90, you get 388.8 cubic inches output by the supercharger per complete engine cycle.

That gives you a difference of 25.2 cubic inches, or 0.42L of extra air. So you could spend $4k+ on a stroker kit and all the machine shop work and labor of pulling the engine for an extra 0.4L of air, or you could spend 10 minutes and $30 and get an increase of 0.42L.

Obviously I am ignoring a ton of variables here- volumetric efficiency, rod ratio, supercharger efficiency, etc- but the point is to illustrate that on a boosted engine, the actual displacement of the engine isn't as important- because you can make up for that displacement by forcing more air in (assuming you can keep it from knocking).

My point is, just because you had a bad experience on one engine, doesn't mean that applies to all engines. Just because your 273 did not have much safety factor/over engineering built in doesn't mean every engine doesn't. Just because my lower intake gaskets leaked on my old 3100, doesn't mean they are going to leak if I buy a 430 Ferrari. We're comparing apples to oranges here.

The 3800 has been more than proven to handle huge power on a stock bottom end- there have been cars in the 10s and 9s in the 1/4 on a stock bottom end. The key is to keep it from knocking. Keep the knock at or near zero, and you'll be fine. Let the KR get out of control, and you're going to chip pistons (aftermarket or not)

That's not to say a 3800 bottom end has never failed- of course you're going to have the occasional manufacturing defect, but cheap and they're a dime a dozen in the junkyard- and 99% of the time, the bottom end holds just fine to huge power. You're going to waste an easy $1000 on all the machine work and parts to rebuild the bottom end (plus the $3k stroker kit)- and you know what you'll end up with? An engine that is more likely to spin a bearing, or trash the bottom end than a stocker. The reliability of rebuilt 3800's with all kinds of 'high hp' aftermarket parts isn't that great- its actually worse than stock.

Spending money to upgrade things that don't need upgraded is a waste of money. I've seen plenty of people with $10k engines get beat down by people with half as much money because they upgraded crap that didn't need upgrading- they had upgraded coils, and upgraded wires, and E99 spark plugs, TPS enhancers, and a custom built bottom end, and all kinds of junk that doesn't add power or help anything. ZZP used to brag about demodding cars to remove useless or crappy aftermarket stuff- and the person left with more power and a more reliable car.

I feel bad for the people I've seen through the years post up all the money they spent building 'bullet proof' 3800 bottom ends, and then end up dynoing terrible numbers for the money they've spent.

If you need to mill .015 to clean the heads up, that thing is very warped. You shouldn't have to take off more than .005 to get the heads straight and cleaned up. If you want to up compression (like for an M90 build) -stick a stock L36 or L26 bottom end in there. You want low compression, stick an L67 or L32 bottom end in there.

Safest bet would be just to buy already ported heads from a reputable vendor- that way you know what you're getting, and not what some random machine shop managed to work up.

3 more rebuilds? You shouldn't have to open it up again, ever unless something goes majorly wrong. Your seals will be tight if you just take off a couple thousandths to make sure the head is flat, and use stock head gaskets. Done. Nothing complicated about that.

Obviously the heads were warped then, or he installed the gaskets incorrectly (ie didn't properly clean the surfaces, etc). As part of tearing the engine apart that far, you would normally check for flatness to make sure they aren't. If you aren't comfortable doing this, take it to a machine shop and have them check it.

That's not a good sign for wanting to mod your car

You are missing the point. What is a built engine that this 18 psi is going on? Is it an XPZ cam, an IS3, IS4, IS3NB, NIC, custom cam- what heads- ZZP S4, IS4, ZZP aluminum, custom port? etc etc etc What compression pistons, 8.0, 8.5, 9.4, 10? The point is a 'built engine' can mean a lot of different things- and on a supercharged engine, the boost can vary wildly depending on which 'fully built' route you go. So trying to call out X boost number doesn't mean anything. As I mentioned before- with a big cam like an IS4, and well ported heads, I'm not even sure if it's possible to hit 18 psi on an M90.

So setting a boost number goal for an engine build doesn't make any sense at all. Saying 18 psi is going to make 550-600 hp is a complete shot in the dark, and is completely dependent on tons of other variables. Maybe it will, maybe it won't, but it's pointless to try and shoot for a certain boost number- if you understand how engines work, and how many variables there are to arrive at a boost number- you'll understand why it doesn't make any sense, especially on a supercharged setup. For a "fully built engine" with a turbo setup- why shoot for 18 psi? Sure you can get a good wastegate controller to make sure it hits 18 and stays steady, but so what? Why 18 and not 20? Given that all the rest of the engine stays the same, 20psi isn't going to be drastically different.

I don't see how what happened on his del sol would have any direct correlation to your car. The weight is totally different on both cars, weight distribution on both cars is different, the engine's power curve is different, I assume he is running a manual, and the tire size is different. So you'd be talking apples to oranges here.

Trust me, that is well beyond 'all the power you could get to the road'- you're talking just under 500 whp. What speed are you trying to race from? What tires are you running on the street- street tires, DR's, slicks? I'll say from a dig on street tires, there is no way you are planting almost 500 whp.

I'll tell you- on my GXP, it should do about 240 whp (300*.8), and has 255mm wide (about the widest tire you could run for DD'ing) Bridgestone Potenza RE050As (a pretty sporty tire, but still very much a street tire)- and I have to peddle through half of first gear before it'll hook at WOT. My monte was even worse (although I never dyno'd it)- before the whipple, it was spinning anywhere in 1st on 245mm BFG KDWs. I can only imagine with double that power- you're going to be peddling through most of 2nd on street tires.

Sure with track prep, cable mod, and some beefy slicks- it should hook ok- but you aren't going to be driving around the street like that. If you go this route- you'd better start looking for a 1" trans chain since they don't make the sets anymore- I've seen them going for well over $1k for the setup on cgp.

If you're going for 600 crank, it would certainly be the easiest route. The M90 will never make it (not even at 18 psi on a built engine, lol)- the highest record was only 464 whp, and that was the shop's own car- you'd be lucky to ever break 400whp with it.

A supercharged setup will be tough- only 3 supercharged setups have ever met that power goal- one CSC setup did 495whp, Intense's shop car did 504whp on a KB Blowzilla, and Jonbob's whipple car did 536 whp (and everyone knows what kind of money and time is invested in that car!). I don't know much about the CSC car, but I can tell you the other two have/had some serious engineering and mods done to them.

With a turbo, there are multiple cars that have broke 600 crank hp, even with relatively mild cams- so that will by far be your best bet. Get a Z7 or Stattama turbo kit, a nice cam like an ST2, a huge FMIC, some ported heads, and a good tune and you'll be well on your way- probably for less than you originally budgeted.



Since it sounds like you haven't started any of this yet- one more thing to consider- you're going to dump $4k into the bottom end with the stroker. $2k into a good set of heads, $750 or so into the fuel system, $4k for an 18 psi turbo kit, or more for a whipple/KB/etc s/c, $4k+ for a built trans, $500 for a set of drag radials to try and make it hook up, and we haven't even touched exhaust, intake, and the nickel and dime stuff- plugs, tstat, etc- so we've got an easy $15k+ there. On street tires, maybe it runs 12s in the 1/4, on slicks maybe high 10s, on the street on street tires- you're limited to roll racing only. The other option you should consider there is what other vehicle options you have. If you include the price of your car- you could build a crazy quick car for the strip for that kind of money. IE- pick up a cheapo fox mustang, gut it, get a used LSX from a junkyard- a 5.3 or a 5.7 or something on the cheaper end- build a basic turbo setup, etc. Or pick up a used LS camaro of firebird, and turbo that. I'm not trying to encourage not modding your monte, especially with the 3800- they're great for doing bolt ons and shaving 2-3 seconds off. Beyond that, the car tends to get more unreliable due to being chock full of aftermarket parts, because it's fwd- its slow on street tires from a dig, and the results for money put in start tapering off. At a certain point, you need to realize that if you started with a quicker platform, you could be going quicker for cheaper. Especially when you're first starting off, now is a good time to evaluate this. But I do suggest doing some searching on clubgp or something first- look at how a lot of the high hp guys have demodded and moved on- and look what they move on to LS camaros, G8s, GTOs, C5 and base C6 vettes, terminators, etc- things that are faster, more reliable at the desired power level, and have more ultimate potential to go fast. Just some food for thought I like to mention whenever anyone starts talking about dumping huge money into a wbody.

 

My Dart is quick but its only got a 318 with 340 top end mild head and intake work. Was thinking about building the monte cus I really like the monte and it is 1000 times more efficient then the 318. It would be easier to mod the swinger and it weighs 1000lbs less. What you saying is I should prob just do a mild build on the 3800 get it to around 350-400 crank or less and just mod the **** out of my swinger. Cus no matter what I do the monte it will never go as fast as I want it to.

 

so people that do top swaps and turbo builds on the 3800 dont do bearings and rings? just curious. seems like cheap insurance to me especially if i were going to throw a power adder at a motor with some mileage on it.

 

Usually you don't touch the block. If you want to do anything to the block, you just go buy a cheap L26/L32 block with low mileage.