What are you calling "high boost"??? 20 psi and up???
Supercharge Or Turbo?
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What are you calling "high boost"??? 20 psi and up???
JeffTheMarine
Well-Known Member
Bill, I see the exhaust manifold in your profile picture and I have to ask where you got it. That thing looks amazing and I am looking at building a slant and have been thinking about turboing it.
Jeff
Jeff
Interesting S-charger there. Can ya tell me about it?still in the buildingstages and havent got my stuff out yet but i like supercharged
however its not anywhere nearcheap
Lag? Only yesteryear has it unless something is ill designed or mismatched.
Todays modern cars, well designed ones at least, have this issue preety much licked. I did here one guy complain about his ride, can't remember what it was off hand.
Effcient? I argue that. How much power is being robbed by the exhaust spinning the turbo? How much pressure from the exhaust does it take to overcome the intake tracks pressure in order to drive the turbo? How contaminated is the incoming charge due to the exhaust back pressure from turning the turbo strong enuff to provide the pressure?
PanGasket
has cork sides
X2 on the info on the S-charger
Turbo lag is mostly the result of that unless you are trying to spin a big turbo for whatever reason floats your boat. I.e. Not wanting boost to come in until a certain rpm or wanting to push more boost later than a smaller turbo could. But if you are dead set on running a large turbo, you should look into using what is called sequential turbo charging but that is just my opinion. Its an alternative to nitrous assisted spooling.:-D
This thread makes me drool on myself. Keep them coming guys. Gotta love them turbos and superchargers.8)
Jeff, my partner in this project (Freddie Nielsen) and I looked on the Internet for a turbo/slant-six header and could only find one for sale commercially, an Australian-manufactured one they were selling for $1,200.
We aren't made out of money, and thought we could beat that price by building it ourselves.
The header you're seeing was built by my partner, a 73-year old retired surveyor who had never built a header in his life.
Expenses to build it (travel to a MIG weld shop, travel to a ceramic coating place, and, parts (flanges, pipe, u-bends, two 3-into-one collectors and a two-into-one collector, plus a turbo mounting flange,) came to just over $1,000.00.
Freddie did ALL the "cut-and-try" on this thing; I ordered the parts but never touched it. He did it all.
I asked him about building another, and he said, "Never again."
Regarding the money we "saved" by doing it ourselves.... Freddie says we would have been money ahead to have bought the Aussie unit, if you count his labor at fifty cents an hour.... LOL
Now, that $1,200.00 unit has gone off the radar, but a FABO member is tooling up for a commercially-available /6-turbo header.... might be available soon. STAY TUNED!!!
And, thanks for the kind words!!! I'll tell Freddie you liked his work...
dgc333
Well-Known Member
I have owned a turbo charged mopar continiously since May of 1985 when I got my first turbo Daytona. The single biggest disadvantage of an exhaust driven turbo compared to a crank shaft driven supercharger is turbo lag. It doesn't make any difference at what rpm the engine is turning at if there is not sufficient load on the engine to require the throttle blade(s) to be significantly open there is not enough exhaust velocity to spin the turbo fast enough to generate boost. So everytime you close the throttle and open it again you have to wait for the turbo spool up before it makes boost. Compared to a supercharger where the boost is directly proportional to the rpm the engine is turning, no lag.
dgc, wouldn't lag be a non-issue if the boost was allready there and bledd off via the waste gate until a wack of the throttle.
(OK, I think that question might have just proven my earlier point. I don't know jack about turbo's. But I'd like to meet Jack.)
Torque on demand was my favorite saying for the motion to get a super charger. No waiting.
(OK, I think that question might have just proven my earlier point. I don't know jack about turbo's. But I'd like to meet Jack.)
Torque on demand was my favorite saying for the motion to get a super charger. No waiting.
Burntorange70
Well-Known Member
Think that is a win screw super charger that duster340 in using. Maybe a whipple charger?
http://www.whipplesuperchargers.com/product.asp?ProdID=1162
My dad is putting one on his motor. Will be doing about 1000HP or so.
http://www.whipplesuperchargers.com/product.asp?ProdID=1162
My dad is putting one on his motor. Will be doing about 1000HP or so.
I didn't see an application for the MoPars.
Burntorange70
Well-Known Member
Have seen them run two different ways. One like duster340's where it sites right on the intake using an adapter. The other way it sits to one side of the motor and is plumed in to the intake. Kind of hard to get them to make the adapters if they are not in high demand. But they will. Even my dad had a bit of a time trying to get them to make one for his LS-7.
pishta
I know I'm right....
Small turbo on a 6 = no lag. get yourself a turbo that seems to be 25% too small. Itll be at full boost at about 3000 and will start spooling right at about off cruise RPM. The wastegate will let you go as high in RPM as you want while still pushing max boost but how high do you want to wind a long stroke leaner? Myth about bottling up the exhaust gas robs power is a little misleading, as the turbo is producing boost at a level higher than the exhaust gas back pressure. the boost PSI is actually pushing down on the pistons with greater force than the loss the exhaust gas is causing trying to keep the pistons down. It is not a loss, it is a net gain on the intake side. With that out the window, turbos really are using free "lost" power. Do you want instant power off idle with a supercharger (really, how much boost are you getting right off idle?) or do you want gobs of torque slightly into your power band? Sure that turbo minivan is going to get jumped off the line by that camaro, but look who is pulling away at 1/8th. and the turbo needs nothing and does nothing at normal cruise so no wasted fuel. Its how you build it. Turbo a 6 and still get 25mpg. And dont run a roots style blower if your running injectors unless the thing is made to run "dry" many use the top mounted carb A/F mixture to lube the seals. My humble vote is for turbo, do what you can.
it is a Lysholm twinscrew supercharger made right here in sweden it is the original twinscrew and was sold rebadged by whipple years ago they are also the same as the new vortech VTS.
this unit is a 3.3liter and it has a "standard" holley 4500 series carbpad recomended max rpm is 13000rpm and 15 pounds of boost but there is people turning them alot harder they may be rated this way to not steal customers from whipple that sold them many years ago under there name
alot of people said that all i needed to do was put an adaptorplate on a normal intakemanifold to run this blower well a few things made that almost hopeless,first of the outlett is in the front of the case and that would have required the case to sit so far back that i wouldnt have been able to use a distributor corecting that would have required an adaptor that also would have been pretty tall its also the thing that the outlet is rectangular as in short and wide wich doesnt match a holley carbflange anyway
to make stuff worse it bolts from underneath wish is solved with this manifold with the manifold having an open plenum from the bottom and a big plate covering it..
alot of these problems could probably be alot smaller with the shorter models that exists
the manifold was cut out of a 40kg billet aluminum piece,and the man who made it asked me to never tell anyone he could make one since it was so much work LoL but it ended up pretty good i think :cheers:
and i hope its low enough to be atleast alitle stealthy atleast that is what i hope aslong as the the solidroller tick, 9.7:1compression and E85fumes wont blow my cover
I knew this was going to be an interesting thread:snakeman:
Mad Dart
Nothing to see Here!
Agreed somewhat. The waste gate keeps boost at a certain level to alleviate over boost/engine damage. The wastegate can be controlled a few different ways. 1) Springs in the waste gate by themselves 2) Springs & manual boost controller 3) Springs & Electronic Boost Controller
The Blow off Valve will relieve the pressure built up in the intake tract when the throttle is let to close. Pressure is relieved allowing the Turbo to still be spinning high on the RPM and relieve pressure to not screw up the turbo and then like you are saying with a Quick Wack on the throttle and the Blow off valve closing, boost should be almost instant at that point...... The wastegate may open a bit right off the bat when the throttle is let to close but the Blow off Valve should open up and take over relieving the boost enough so the wastegate stays closed allowing for a quick spool up when the throttle is smashed again and the blow off valve closes.
This conversation here is regarding a car of any kind already on boost and then letting off the throttle then back on boost.
Getting a turbo initially to spin up enough to create boost is a whole different animal.
JeffTheMarine
Well-Known Member
Well I suppose that I will have to look into "making" my own then.... Save myself some money if nothing else is availible. Someone was telling me at one point that I thought the K car turbo's would bolt straight up to a slant six stock exhaust manifold or something like that. I am sure I can be very wrong but that is what someone told me.
Jeff
Jeff
LOL, X vs O is allways good and this is a convo. not a flag waving yelling match. A big thumbs up for adulthood convo's!
From another newbie...
Originally posted in a different forum... the wrong one.
A year ago, I couldn't even spell "slant six"... but I got on the Slant six.org website and this one, and began reading, and learned a few things. That's pretty amazing in itself, 'cause I'm what they charitably call a "slow learner.":read2: Sometimes, a lot worse,,,:angry7:
Be aware that my personal "hobby" car is a 1972 Valiant with a 360 Magnum V8 equipped with a Vortech V-1, S-Trim, serpentine belt-driven centrifugal supercharger that makes about 525 flywheel horsepower. Not that THAT is any great shakes ('cause it's not, I realize) but it does give you a clue that I have not been a "slant six guy" from day one.
As I immersed myself in the postings about /6 performance, and videos on You Tube of various /6-powered cars, I began to realize some things about these slanted little devils that had escaped me for years. Here's are some things I had missed.
In a general way of looking at the /6 archetecture, it says one thing in a big way: This cylinder head may be a perfect head for a 170 cubic inch engine, but trying to make a normally-aspirated 225 breathe through those same 170-sized ports is a job for Superman.
What I mean by that is, the ports and valves, as manufactured, are just too small for the amount of cylinder displacement they are asked to feed, in a high-performance 225 environment.
The /6 has 225 cubic inches, If it were a /8 it would be 300 cubic inches with 8 of the 225's (37.5 cid) cylinders instead of 6.
Just for comparison purposes to show what size these ports and valves are, the 1967 Chevy Z28 came with 302 cubic inches (virtually the same size cylinders as a 225 /6 engine,) and their intake valves were 2.02" in diameter (slant six "oversize racing valves" are 1.75, or fifteen percent smaller than the "stock" Chevy valves, and the 1.6" Chevy stock exhaust valves are still 6-percent larger than the "oversize racing" /6, 1.5" exhaust valves.
The Z-28 Chevy ports in the head are commensurately larger, so that the flow numbers are a pretty good match for the valves, in their stock configuration.
The bottom line is, a mildly ported (302) Chevy intake port will flow close to 300cfm to feed the same size cylinder that the /6 is trying to fill with that 1.75" valve that is in a head, that after porting, will flow 220cfm, absolute max...
A big, heavy crankshaft doesn't help matters, especially when winding up 1st gear.
So, here's what I have learned:
I watched videos of the chopped, 2,350-pound MadMax 1st generation Valiant with a normally-aspirated /6 running 11.50s with NO power adder of any kind.
That car is incredibly fast and quick (watch how it hooks!!!)
I've never seen anything like it!
I didn't REALIZE that a normally-aspirated Valiant or Dart could run like that!
I happened onto two more videos on You Tube that opened my eyes even further.
There were two videos of turbocharged 225's that blew my mind. Tom Wolfe has a 3,300-pound '70 Dart that has run 11.02 with a new motor (at 122 mph), into a 15-mph headwind, while another forced induction racer (turbo66Valiant) posted videos that showed his pristine '66 Valiant running some 10.50's, which is about a full second quicker than the already fast, but unblown, Mad Max car.
Not to belittle the Mad Max car, because it's stupid fast for its combination, but that '66 Valiant is I believe, 500 pounds heaver and a full second quicker. And, its running a 727... probably about .2 slower than a 904.
So, what did I learn from all this???
Not so fast; I said I was a slow learner, and I surely am...
I did a lot of research about the /6 motor, and one thing stood out:
It's built like a brick pagoda. Its aluminum ancestry seems to have left it with an infrastructure that has no equal in the modern automotive world, when it comes to strength and ridigidity.
Remember that big, heavy, crankshaft I was carping about awhile back?
Well, I found that the early models are forged, have internal balance, and bearings the size of the 426 Hemi.
As close to an unbreakable stock crank as you can probably find.
The cylinder walls can be bored over .100", the head can be milled that much if need be, and the top of the block is pretty thick, but I have no reliable numbers for that.
What all this means is, unlike the Buick GN turbo motors which (the stock stuff) don't seem to want to stay together if the boost goes much over 25-pounds, it's an open question as to just how much boost one of these /6 motors could stand, if someone greally got serious, because K-1 is making some great-looking forged rods for a 225, and forged pistons are available from Wiseco in a .065"-overbore, creating a 234 cubic inch motor.
Shaker223 and turbo66valiant are probably generating over 500 flywheel hp as we speak, but can 600 hp be far behind?
It's not necesssary to build a 500hp motor to have fun with a turbocharged /6.
One of Tom's early engines was pretty much stock with a Buick turbo stuck on the bottom of a stock exhaust manifold, and it went high 12's...
The possibilities are endless!:cheers:
I'd think twice before pulling that /6 out of ANY A-Body....
Might be shooting yourself in the foot...
JeffTheMarine
Well-Known Member
I like all the info you just posted about slants and I have been looking into turboing and reading as much as possible lately. I have also been looking into which turbo to use and more often than not people say that you should use and are using the Buick GN turbo's. My main question is what turbo exactly does the Buick GN use?
Jeff
Jeff
DusterDj
DUSTU2
He is making a good point. I see there isn't much love here for the centrifugal supercharger. People forget how quickly the swept the market and it oh so depends on what you are looking for power wise and where you want it. If you think about it, it has the turbo technology incorporated into it. I choose the dual F2 and will match it up with any twin turbo. My reasoning is that I want my power on the short end and dare the turbo cars to catch me. Centrifugal supercharger are torque monsters and if you 60ft well, you can do a nice ET. Nothing top ends with the Turbos but centrifugal supercharger aren't to far behind. I'm going big cubic inches long stroke to help suffice the power requirements for the gear drive. In all, it is what ever floats your boat. Non the less, you will pay to play...
Mad Dart
Nothing to see Here!
That is a pretty cool set up you got there! I agree, whatever floats your boat AND you WILL PAY TO PLAY! No way around that one!
Damned if I know (I'm an ignoramous when it comes to turbos) but I think that Shaker223 had one on his car a while back, so maybe he could tell us. Tom????????????????????
Shaker223
Boost Rules
I used an 87 GN turbo. It is a TBO348 (also used on 86GN's as well).
Here is the compressor map.
http://www.turbobuick.com/forums/turbos-turbo-related-parts/247569-stock-tbo348-compressor-map.html
Good enough to get a stock slant (with a few minor changes) into the 12's.
Tom
Here is the compressor map.
http://www.turbobuick.com/forums/turbos-turbo-related-parts/247569-stock-tbo348-compressor-map.html
Good enough to get a stock slant (with a few minor changes) into the 12's.
Tom
turbofreek
batcrap crazy racing team
That is a badass setup no doubt about it. It would take twin 88's to run with those I'm sure. However a centrifugal blower is not as Much of a torque monster as a turbo. I wish they where as all ky turbo cars would have never been. The one thong about turbos is people say that the lost power to turn a turbo is there. Well the answer is yes and no to that question. With a turbo in the exhaust stream it creates back pressure. In an n/a engine that would kill power from mid range up. However a turbos back pressure creates torque that was not there before its addition of pre manifold positive pressure. Now there is additional torque before boost is seen on the gauge and a ton more once it is there. How bad *** would a centrifugal supercharger be if it could create max boost way before peak rpm? Well that is where the screw and roots blower came to be so well known once the Ford lightning came around with one they hit the ground running. Flowers instant boost off idle and the turbo full boost 1000's of rpms before redline. However they become less efficient in a hurry cuz they heats the air so much. That is why air to water coolers are done from the factory, cuz it needs cooled off significantly more then a turbo or centrifugal. I know I'm bias to turbos and I can't help it. I've ran them all, centrifugal, roots, twin screw, n2o, and turbo. The best performing out them all was by far the turbo. Not saying the other don't make great power, cuz they do. I believe that my turbo was much more predictable, reliable, and so much more fun to drive. Not one other power added I've had could break the tires loose at any given time like my turbo could at 55mph. Just shear awesome power. All the ones I've had all made the same HP, but the turbo was much more powerful of a setup in the torque department. Also why it was quicker and faster even out of the hole. I will say if your not capable to see a turbo build through to the end don't do it. It take determination to finish one and tons of patience. Most the rest can be bolted on and go in under 12 hours. Planning on a turbo build to be a few weeks to get it all squared away if its your first go at it.
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