Super Charger

[DartMan360]

I e-mailed KRC performace and they said they have a superchager for a 360 magnum motor. They say it will bolt right on using the carb with no problem and will be done in a couple of hours. He said we can pick up between 400 and 480 more hp on top of the 400 thats already their. All this for 3100 bucks that includes everything. Now my question is that has anyone ever used a super charger? Or have heard anything good/bad about them? any suggestions or comments will be apricted.

[blownhemi]

I've had a few.

I had a 360 with a B&M 162 which was custom made kit. A company called Max Wedge performance makes the manifolds (cast alloy not welded) and pulleys over here. Now with 8:1 comp and a small cam .458 lift and 218 degrees duration at .50, it made 270hp at the rear wheels. It was 100% overdriven and ran fine on pump fuel but only put out 6-61/2 pounds boost. Now on pump 95 octane fuel and in full street trim (exhaust/street tyres) it used to run 12.7 at 108mph in a 3500pound car(race weight). The whole thing was totally streetable, it had 3.5 gears and a stock stall convertor and could criuse nicely, but put your foot down and hang on. I love blowers but I wanted more so now I'm building a 6/71 set-up on a another Max Wedge manifold.

That being said though, an extra 400-480hp sounds like bull. You can't just drop a blower on and expect in to run right, epecially when your motor is set-up to make big power naturally aspirated. You'll need forged low comp pistons for a start unless you want to run race gas all the time. to get that sort of horsepower your looking at in excess of 15 pounds boost and an intercooler. I take it this blower is a vortech or paxton set-up, because you said they were using the original carb. The best way to get power from these blowers is to use injection. In Australia we have several cars that make in excess of 600hp at the rear wheels with Vortechs/intercooled on injection. However I have never seen anyone get these sort of figures out of a carby set-up, due to the fact that the carby cannot meter the fuel as well as injection.

I once bolted a blower on the side of a 265 hemi six without modifying it. It ran pretty good but needed Avgas (103 octane)to get the best out of it. I tried running it on 95 octane but it blew a head gasket. This engine was only 9.5:1 comp, but with 7-10 pounds boost on it, it would ping without water injection and all the advance taken out of the timing, which greatly affected it's streetability. It was very slow out of the hole but picked up n the top end. this set-up made 216hp at the rear wheels with avgas and water injection. However when I tookit to the track I tried to run it on 95 octane but it would just detonate constantly and ended up blowing a head gasket after a 14.4 second pass which was only on the throttle for 1/2 track.

Blowers are very good things and an under-bonnet set-up is the ultimate sleeper route, but you have to be careful who and how, setting it up.

[TT440]

Didja ever think about turbocharging?
Blownboy has a few good points. I will disagree with the abilities of a carb to a point.
Around 15 psi, the carb will begin to have difficulties with metering fuel for the denser air charge.
I'm currently running 8 psi out of my twin turbo 440 and not having any carb related problems. I plan on stepping up the boost as far as I can fuel it, but 15 psi is probably the working limit. At that pressure, I will probably have in excess of 850 hp. That is a little more than I bargained for when I built this thing.

The blower won't move more air. The blower will move THICKER air. Big difference. The engine can only handle so much volume. 360 inches is 360 inches. Your spare tire can hold 12 psi or 35 psi. It's going to have the same amount of air but at different pressures.
Be sure that you upgrade the fuel system when moving to a blow through setup. If you build more boost than fuel pressure, you'll pressurize the fuel bowls with boost and push the fuel back into the tank. If the pump makes enough pressure to over come that, it will flood the carb when not under boost (idle, cruise, etc).
The trick is a rising rate or boost refrenced regulator/pump. Boost goes up, fuel pressure goes up.
I can't tell you how much fun it was getting my system hooked up right.
A carb will do it. Injection would be better.

Check out my link for a few pics. Nothing fancy yet. A better page is in the works.
TT440 page

[blownhemi]

Mate, that a really interesting set-up you have there. I noticed you have an O2 sensor wired it, what sort of A/F figures do you have under full boost. Have you ever had it out on the strip?

I don't understand your reference to PVC tubing? Where did you use PVC? Wouldn't it melt from high intake temps?

It's good to see people thinging outside the square. You mat be interested in an Australian Turbo site called Full Boost .com.au . It has alot of Autralian Turbo cars, although there is alot of Jap stuff there are some interesting cars there. There is a Chrysler Centura (I don't think you got them in the states), with a turbo hemi six that run's 9.8 at 138mph with a carby/turbo set-up.

I didn't mean to say that you couldn't use a carb but they raise some issues that have to be addressed such as you mentioned with the rising rate regulator and such. In Australia we have access to some excellent injection gear, actually more than you do in the states. Go figure?

I think over there it tends to be that guys would rather buy something off the shelf (obviously not you tt440 ). Than have to go through an exhaustive R & D program. Last year we had a car at the Summernats (the biggest car show/ event in Australia) That had a twin turbo 355 holden stroker engine that made 850+HP at the rear wheels. Unfortunately the owner died in an accident in that exact car earlier this year while travelling at 280 kph. RIP Todd

[kekoakeakane]

The blower won't move more air. The blower will move THICKER air. Big difference. The engine can only handle so much volume. 360 inches is 360 inches. Your spare tire can hold 12 psi or 35 psi. It's going to have the same amount of air but at different pressures.

I'd have to disagree with this statement. It's along the right lines, but you actually are moving more air. The constant gas law PV = nRT says that if you keep temperature (T) and Volume (V) the same and increase Pressure (P) you have to increase amount (n). You are right that the volume of the engine won't change, but a blower or turbo both put a larger volume of air into the cylinder than it would bring in on it's own. This has the effect of a 360 CID motor burning the volume of air/fuel mixture of a larger (i.e. 440 CID) motor in the same cycle. This is why the pressure increases, because you are putting a larger amount of air into a container of constant volume. Is this clear as mud.

Taking your tire analogy, if you were to blow up two balloons with the air from each tire, the one with 35 psi would make a much larger balloon than the 12 psi tire.

[383-man]

Mopar Muscle did an article on a 360 Challenger and put one of them superchargers on it. The car dynoed at 359 hp and with the supercharger it had around 600 I believe! I do remember the car ran 13.0,s without it and went 11.50,s with it! If you like I can dig up the mag with the article as I still have it! Just let me know ! Ron

[blownhemi]

You guys must talk different horsepower. I'm talking about real horsepower not kiddies ponies.

A car that has 359 HP at the rear wheels should run into the 11's.

A car that has 600hp at the wheels should run 9's properly set-up.

Unless you are talking about the engine being dynoed, but you said the CAR was dynoed. So I assume you are talking about a chassis dyno.

[dewme5]

hey dartman360.... do the turbo thing!! you can spend that other $2600 on something else. just taking the numbers your engine will support. (what its built to handle) and then when you want the boost to come in, how many pounds you want. you can get the right turbos! single.. double.. what every you want. a single hx35 off of a turbo diesel dodge will support 700 hp on its own. now....... its not so easy as a simple bolt up. there is some work involved... but a little work isnt a bad thing.

[DartMan360]

Thanks for the input everyone. Paxton makes another kit that will persursize the bowls. He didnt give me the price on that. I'm gona call them monday and actully talk to someone. Then ill call back and talk to someone else and see what i get. That was a typo on the hp part. it was 300-380. Sorry about that. But that is still alot for a bolt on and for 3100. Even if we only get 300 plus the 400 thats their. Thats 7 which will put the car into the 10's. The car is running 12.40's now. We have had the tranny built and a bigger converter put in. We pick it up monday and might go to the track Tuesday. I will let everyone know how much more we get out of it. But back to the super charger. Does everyone think that is a good price for 300 or more hp? We wont put the juice on the car but will consider anything else. As far as the Cam2 part. It dont matter coz that is what we run in the car now. So that wont change anything. And for that wild slant 6 with the blower...Its pretty sweet looking. That is what we try to do as something that you have never seen before and we havent seen a supercharged 360 around here.

[383-man]

BlownHemi of course thats flywheel horsepower as they said they dynoed the eng. I agree that 359 HP at the rear wheels would get high 11,s in a good car ! This is what the article in Mopar Muscle said as they did not put it on a rear wheel dyno ! Ron

[TT440]

Actually, the blower will not move more air. Go back and look at the thermodynamics again. If you compress air, it will heat up. The laws and theories will give you the "correct" temperature and density change. In the real world, we are unable to pack a super efficient compressor under the hood. The best of them run in the 75% range. You're talking considerable heat buildup. That's why all-out turbo cars use intercoolers. Mine just hasn't made it on yet.

I would be very careful about dropping a blower of any sort on your engine. If you're running over 9:1 compression, you're going to have detonation problems. A quick fix is thicker head gaskets if you're close to 9:1 comp. If not, then you may need to consider a set of big chamber or uncut heads. New pistons may be required. Otherwise, you're going to be stuck with low boost and not getting the most for your money.

The PVC piping was going to be used for the intake plumbing. Schedule 40 PVC has the temp and pressure capacity. I ended up ditching it for aluminized steel when I couldn't quite get the proper bend with PVC. If you look at the pics again, the main pipe feeding the carb was going to be PVC. I still have all the pipe in my garage.

I don't have any numbers on the car yet. I can tell you that using 2/3 throttle and 8 psi the car accelerates harder than the previous 440 with a Mopar 509 cam.

My goals were 650 hp, 130 mph in the quarter, and pump gas. As it is, I get 17 mpg on pump fuel and have no detonation problems. I'm sure the power is there too.
If I replace the fuel return line, I should be running properly and will get some dyno numbers.

[blownhemi]

TT440- that's some impressive numbers, keep us informed.

383-man-sorry to sound like a smart-arse but when you said "Dynoed the Car" I assumed that you meant chassis dyno. 359 and 600 are good for what you were saying. Although with 600hp they should of got 10's. This is the problem with centifigul set-ups. They produce high boost but only at high rpm, whereas a roots blower can produce full boost at 2000rpm. I'll tell you it's alot of fun.

Oh and Dartman, that's not a slant, it's a hemi. Chrysler australia built a 6 cylinder called the hemi six. It was available in 215ci,245ci and 265ci. In it's highest factory output the hemi265 made 302hp and ran the standing quarter in 14.4, so it was quite a weapon considering this was on 1971 narrow tyres. With modern tyres high 13's from a standard car are quite possible. Man you could disappoint a few mustangs with that!!

[kingjr]

Sounds like my 383 is the perfect candidate for a blower! If theres any money left after my Hemi build up maybe I'll try it! Those hemi sixs rock, love the yellow charger on the cover of mopar muscle smoking the tires. My mothers 69 slant six Valiant could only dream of that, it was indestructable though! Great post guys, I appreciate the info. <><

[Dr. Righteous]

Man, you are building the turbo charged setup that I always dreamed of! I have studied supercharging/turbocharging for a long time like you and am convinced it is THE WAY to make power. I have one question as to WHY you chose to modify a set of headers to mate with your turbochargers rather than use a pair of stock manifolds??? The plumbing would have been eaiser and because of a pressurized intake and the fact that your exhaust system isn't just a long tube anymore because of a turbocharger any benefit to using headers are gone. You cannot get the desired 'scavaging' effect like on normally asperated engines. Besides; your don't really need it. I am sure you considered this. What was your idea???

[TT440]

It is possible to get a scavenging effect. The headers will provide much less backpressure than the log manifolds. My headers are cobbled together and are destined for the scrap heap after a new set is built.
Another slap to the manifolds comes from the fact that you can't flip 'em upside down. They block the spark plugs.
If you swap 'ep side to side, then the dumps will hit the engine mounts. The steering gearbox would be in the way too.

I think a C body driver's side would clear on the passenger side, but you'd have to rig up a new one for the driver.

When playing with a pressurized engine, you still get the same benefits from high performance parts. Higher flowing heads and exhaust still make more power. Back pressure after the turbo is one of the biggest problems. Dumping the exhaust as soon as possible will give you a little more scoot.

[curious]

i saw a 585 hp S/C'ed 318 over at moparts.com for sale for $4800. i cant find it no where but heres a link with all the details:
this was built on a $600 long-block (including labor)

http://ramchargercentral.com/cgi-bin...187910&start=0

[Dr. Righteous]

The greatest benefit of supercharging is what?
It is actually being able to achieve volumetric efficentcy without having to run big cams and enlarged ports/valves in your engine. The PRESSURIZED intake charge give you the best of everything. You don't need large cams with an overlap to help scavaging. Additional overlap will hurt on a supercharged/turbocharged engine. Also tube headers are really unnecessary because their purpose was to AIDE in achieving volumetric effiecentcy. Low back pressure is only part of the picture. HOW it work was the tuning of the exhaust pulses. Each pulse "pulled" the next pulse along with it. A turbocharger 'scrambles' the pulses so the effect scavaring is canceled. Keep in mind because your intake is pressurized, your exhaust is pressurized also. When the exhaust valve opens the higher pressure bursts out rather than relying mostly on the exhaust stroke to clear the cylinder. I know bigger ports/valves and so on mean more squeezed air but that should be for all out racing. It probably wouldn't be necessary for a mostly street driven turbo car.

Gonna run stock mainfolds when I build my turbo car. Just have to figure out where to get the turbos

[rb77413]

Headers actually do help with a Turbo. They can even out the exhaust pulses, which will in turn help prevent the Turbine froming plusing as it is spooling up. I have a 87 Omni that I swapped the driveline from a 85 GLH into. So I love Turbos. I also have a nice 383 in a 70 Newport Convertible, so I play on both sides of the field. Turbos don't like any backpressure. Less BP will help build boost faster. A down side to a turbo actually is the backpressure it creates itself, by forcing the exhaust across the turbine. It flows from the outside to the inside in the exhaust scroll. On a not so good Turbo housing intake to exhaust press can be as high as 1:3 Meaning if ur running 10lbs boost the exhaust pressure can be as high as 30 lbs!! Just my .02 Boost is very addictive Try this link for some info on a 10 sec K-car
http://dodgegarage.www2.50megs.com/index.html

[TT440]

I'm familiar with Relentless.
He's got it dead on with the turbo headers. Good stuff there.
Performance heads will also give the same performance increase as you would get on a atmospheric engine. If the ports are smoother, the boosted air gets through easier. There's much lower turbulence as well as higher volume.
Remember that air must be accelerated and decelerated. Think of a train starting to roll. If it's a long train, the engine is at half speed before the caboose moves. Same with air. It's squishy and stretchy. When the valve opens, it gets squished into the cylinder under boost. It accelerates past the valve. Less obstruction means easier acceleration.
As far as cams go, you're correct about overlap. I had to ditch my long time friend (MP 509 cam) and slip in my custom spec cam. The lift and duration are similar to the MP 484 cam, but the lobe separation and overlap are different. The ramps are more aggressive too.
A stock 400 cam would make a real powerhouse when used with turbos. Best of all, the stock drivability would go unchanged until you started feelin a little froggy.

Yeah, I'm a boostaholic. The cop car will get a pair, the Belvedere has a pair, and the Cummins is kicking out 27 psi.

[curious]

tt440 im tottally lost. im interseted in a tt440 setup but i have no idea about your choice in turbos, the cost, plumbing, anything. also whats the specs on this cam and how much? or cant u tell us? i plan on a custom header setup. use hooker flanges, 3 1/2" main and 1 7/8" stepped to 2" primaries. i wanna build a efi setup though. how much boost is the 440 runnig? 27psi? whoa!

[ben byrd]

Consider these notions when you are building your headers to feed the turbo's. Exhaust velocity and pressure drop should occur AFTER the turbine wheel. Therefor would it not be desireable to have primary runners larger than exhaust valve diameter and, of course, as short as possible.
Also, a comment on pressure vs. volume. Remember that the measured pressure is back pressure,ie.. resistance to flow. Volume is what we want not only in the plumbing but inside the engine where a lower compression ratio gives multiple benefits in the "size" of the explosion but an increase in compressed volume nearly proportional to the reduction in CR (within practical bounds) plus an increase in exhaust volume. The limiting factors are pre-ignition and combustion chamber component materials strength. I like torque @ < 6,000

[TT440]

It has all the techie info on it.

When selecting turbos, gather every bit of info you can about your car setup and what your plans are. Take it all to a turbo pro and let them suggest the turbo you should use. The combinations are endless.
If you want to do it yourself, be warned that there is lotsa high math and confusing charts to look at. Go to Turbonetics and look at the compressor maps. If you can figure them out, go ahead and do your own.

My cam specs are listed on my tech page. They've buried in there somewhere. The idea on my grind was to get a good area under the lobe, make maximum cylinder pressure, and evacuate the cylinders without letting too much raw fuel blow by.

I intentionally kept the ports and headers small to keep velocity up. Since this engine has kinda low compression, I didn't want it to be doggy when not under boost. This is a cruiser.

I spent two years trying to save cash for this. It didn't happen overnight. Since I was a seriously broke boy, I spent my time studying what I needed to do. Once the cash was here, I was prepared to do it right.
Sharing my triumphs, failures, and bone-headed mistakes with the folks on the "other" boards really kept the build up fun and interesting.

I dropped $632 each for my turbos. The custom cam and lifters were $274. I used the Summit 440 rebuild kit with 9:1 forged poppers for $600 or whatever they're advertising.
The wastegates were spendy at $452/pair. You can save $400 by using integral units instead of separates.
Other than that, there's nothing special about the engine. Stock heads, block, crank, rods, etc.

I did my homework over and over for two years and only spent the cash once.

If you want to get info or simply understand turbos better, go to
Cartech.net and get the book Maximum Boost. It is a priceless reference piece. It's very modern and up to date. The author was kinda enough to spend time on the phone with me and showed interest in my project. That says a bunch for a guy who does this stuff day in and day out.

Now go dig through that boring/tedious page I've got (working on upgrade) and you can get enough techie stuff to choke on.

TT440 page

[DartMan360]

I have talked to some people this past weekend at canfield. I told them what we had and we were thinking about putting a super charger on. 9 out of 10 of the said thats the way to go because your less likely to brake parts on 900hp super charged motor than a 900 hp natural asp. motor. If we can get rid of the convertable soon that is what we are going to do. What should we look for? And good kits out their. The one that we were looking at was not adjustable but you can get up to 480hp. I was rite on their first post i put. This rite here will be to much but we can alwise not use it all. We want to do this on 10in slicks. This kit was 3100 bucks and came with everything you need. We are going to keep looking around and not jump on everything rite away. So what should we look for? Anyone know any good places that sell them for magnum motors running on a carb?

[71 scamp]

900 horse supercharged street crate motor! Did they try to sell you a bridge also??
You only need about 500-525 horse to run 10.90's in your a-body!

[DartMan360]

We wont use all of the hp. Just what ever the car will take. If it will alow us to run in the low 10's that is fine. But it should get us somewhere in the 10's. If we get that 340 their is more of a chance of us braking more parts in that than their is with us going with the supre charger. I think the super charger and the cage will be this winters project. Hopefully it wont be a headache like this past winters project of painting the car. Anyone know any good places that make a descent 10 point cage for an A body? Without doing anything to the stock dash. I have seen chasis engeringing and I dont like them. Also is it cheaper just to build one? We have all of the welders and a buddy who has a tubing bender that he already said we can use. S & W wants 230 for a 10 point. Thats shiped to your door.