Yeah really alot of mis-information on this subject. Its not about peak power with a twincharge kit, its the power below the peak. If you have no desire to have ALOT of usable power and torque in the lower RPM than dont get it. Its as simple as that. It works where its suppose to work.

Josh F wrote:And for my example of useable power and the Z06 example… I DID in fact keep up to a C5 Z06 on a 1/4mile race… so that proves right there it makes more usable power and makes up for it only being a 2.4L 4cyl engine when up against big V8’s

Ok.........I don't really care if you did or not, just cause you did doesn't somehow mean twin charging is the way to go....I'm lost as far as how you think this is a proof of concept?

So, lets say your twin charge setup makes 400whp from 3k to 6.5krpm and the torque curve is copacetic, lets even say you shift anywhere you want between 4.5k to 6.5k to stay in your power band. Now you roll up to a turbo J with 400whp @ 4.5k with 550whp peak @7k, again with a copacetic torque curve and this guy shifts from 7k to 4.5k.... Would you really think you would stand a chance? How much better would you feel if you knew he saved the $ and the weight of the SC setup?

Also, your sig power levels (305/315:HP/TQ @ 15psi and 420/425:HP/TQ @ 20 psi) is nothing special. Brian Wisniewski has dropped 437/380:HP/TQ @ 17psi and there are a few other setups with similar #'s or better. So...........


"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

NoMoreGroceries wrote:Yeah really alot of mis-information on this subject. Its not about peak power with a twincharge kit, its the power below the peak. If you have no desire to have ALOT of usable power and torque in the lower RPM than dont get it. Its as simple as that. It works where its suppose to work.

Exactly... you’re not always going to be sitting at that perfect 6,000 RPM ..

Joshua Dearman wrote:

Josh F wrote:And for my example of useable power and the Z06 example… I DID in fact keep up to a C5 Z06 on a 1/4mile race… so that proves right there it makes more usable power and makes up for it only being a 2.4L 4cyl engine when up against big V8’s

Ok.........I don't really care if you did or not, just cause you did doesn't somehow mean twin charging is the way to go....I'm lost as far as how you think this is a proof of concept?

So, lets say your twin charge setup makes 400whp from 3k to 6.5krpm and the torque curve is copacetic, lets even say you shift anywhere you want between 4.5k to 6.5k to stay in your power band. Now you roll up to a turbo J with 400whp @ 4.5k with 550whp peak @7k, again with a copacetic torque curve and this guy shifts from 7k to 4.5k.... Would you really think you would stand a chance? How much better would you feel if you knew he saved the $ and the weight of the SC setup?

Also, your sig power levels (305/315:HP/TQ @ 15psi and 420/425:HP/TQ @ 20 psi) is nothing special. Brian Wisniewski has dropped 437/380:HP/TQ @ 17psi and there are a few other setups with similar #'s or better. So...........

You still don’t get it... maybe some videos of someone else saying what I am saying will get threw?

But this Brian guy making 437whp @17psi... what dyno was this on, what gas was he running etc.... I can almost guaranty you he was running 91 octane because there would be no way a 2.4L could push 437whp on 91 unless he was just dumping in alky with an alky injection system.

ahah I do have the perfect video for you to watch which shows exactly what I am getting at… A little Top Gear to explain it all.

http://www.youtube.com/watch?v=VVt1IjIdLxY&feature=related

Watch this starting at 50seconds... this is a car that kept up to a Lamborghini around the track... and at 1min40sec he says exactly what I am trying to say... THANK YOU JEREMY CLARKSON!

Here is the hole video…

http://www.youtube.com/watch?v=8AMIoQUCEvY

Starting at 3min20sec is where it really starts… It shows that YES having great top end and being able to keep your RPMs up is great… but the first video shows what I am trying to say and is more realistic for a street car.. unless you keep your engine screaming at all times because while you are down shifting, that guy next to you with more usable power is off and running and even if you do have more peak power, you are now having to run him down, then you get into corners and if you screw a shift up on a twincharge set up and your rpms drop off its not a big deal you just power out of it, or if you mess up the other way and your rpms go up, well you still have big top end as well... where as a turbo only set up, you better hope you dont mess up and drop your rpms off... again this is just an example just trying to get at the hole "USEABLE POWER" idea






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

And one last thing... I get that the video is showing an extreme situation and your not going to get caught like that, but it still shows you why a good low and AND and good top end are really what a good set up should have.

Sure you could get a good size turbo on a jbody and have good low end and decent top end... but in a twin charge setup you can get a HUGE turbo that will have unreal top end and you don't have to worry about the bottom end lag because you are going to be making big power down low as well..



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

Just something else to throw in...it sounds like the twin charged setup would be great for everyday driving especially...have a lot of power no matter what speed or rpm's right? Thinking that would also be very beneficial in autocross.

John02 wrote:Just something else to throw in...it sounds like the twin charged setup would be great for everyday driving especially...have a lot of power no matter what speed or rpm's right? Thinking that would also be very beneficial in autocross.

Correct... granted you try and keep your RPMs up but there are times when they drop and if you’re running a set up that needs 5,500rpm to make power... well have fun...






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

Ok, you bring up some terms like 'screaming' and 'HUGE' turbo and such. Lets think about this for a second. If you have a GT35R/37R which has the capability of lifting your intake pressures north of 25psi on our engine do you think a larger turbo is needed? I agree, you could run a M90 + GT42R twin charged setup and yes it would be a mean bitch, but think about the custom parts and $ involved. When 700hp is possible with a GT37R with a pretty 'decent' power band, maybe not as wide as you would end up with using a GT35R but it would be close and not night/day like you'd get from a 42R only setup. Really I don't see our blocks holding up well past 600hp so I dont see the need to throw the SC and turbo at it to flatten out the power band when the power is there to match the gears. Looking at stock dyno graphs on a Z06 it shows 505 @ around 6.5k but around 300hp @ 4.4k which is about where it's 1st-2nd-3rd gearing is going to drop it on shifts with stock axle ratio. This begs my next point, a V8 must be ABSOLUTELY SCREAMING to turn 6.8k huh? LOL. I dont know why you think 7k on a 4cyl engine is "screaming". Honda's can turn 9.5k, @!#$, 1.5L 4cyl's can turn 15k+ on some motorcycles. Really 7k is nothing man, not much beyond stock limiters on any engine currently in production across the board. I know I'm picking at opinions here a little, but you seem to forget that the same car you raced against was shifting @ 6.5k down to 4.4k....this rpm swing here is about what to expect out of a J and any well thought out turbo setup's power band too.

The more I think about it, there is a place for twin charging but it only makes sence in positions where the turbo is so large that you end with night and day power bands ie: GT42R or so and need to bring that down on the far right(since the SC will steal power at the higher RPM's than that on a turbo setup alone) in exchange for a more level but lesser peak power band. In those situations fine, but also your goal HP would have to be astronomical. Which I really don't think is needed in our applications for several reasons, 1st being traction. On Q4Forums there is a dyno graph of a 5XX Q4 with a nice good useable power curve on a turbo only setup. A twin will drop total power in exchange for longer power band, but if it''s possible to achieve the power within the gearing, the rest is a waste. Not to mention you can gain from the higher peak that the turbo alone will give you that you wont see on the twin setup. Not to mention added weight, ect.






Edited 4 time(s). Last edited Wednesday, November 18, 2009 9:08 PM

"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

Josh F wrote:You still don’t get it... maybe some videos of someone else saying what I am saying will get threw?

ahah I do have the perfect video for you to watch which shows exactly what I am getting at… A little Top Gear to explain it all.

http://www.youtube.com/watch?v=VVt1IjIdLxY&feature=related

Watch this starting at 50seconds... this is a car that kept up to a Lamborghini around the track... and at 1min40sec he says exactly what I am trying to say... THANK YOU JEREMY CLARKSON!

Here is the hole video…

http://www.youtube.com/watch?v=8AMIoQUCEvY

I actually think this proves my point better. Notice when he was racing the Lambo, had no problems keeping it in the power band? Did you happen to notice this or did you assume he installed his pocket SC when the camera looked away? Yes, he shows turbo lag on his next example...fine, but seriously are you too lazy to shift? One simple solution, SHIFT, it's cheaper than putting an SC on it...I promise. So is that it? Is that the whole point behind a twin charger system? It saves you the trouble of shifting? Still I can think of a cheaper solution, get an auto trans.

I'd rather keep my IAT's low, save the weight, have the higher top end, and umm.....what was the...O yeah, SHIFT! - Ya, not a problem for most, myself included. For others I guess you gotta add weight, increase air intake temp, loose top end power, and cost a lot more money.......


"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

Maybe read this? If there isn't enough information (and a soon to be finished twin charged car) to make a proof of concept, I'm lost as to what you're looking for.


2010 Honda Fit LX

I have no problem with proof of concept. I know it works, whats worse is I know HOW it works...which is where the problem is. It steals top end in favor for a flat power curve....if you dont have massive RPM swings on shifts you don't need the low end it gives, to that end, since a J doesn't 'need' the low end because of the gears we have it only steals top end power. So you pay more for less. Now, IF there was an electronic SC clutch system to disengage/bypass the SC altogether at upper RPM's where the power theft happens...now your on to something and I could really be down for that. However this all begs the question, at that point it might be easier to do a compound turbo setup or a twin offset turbo system to achieve similar results.


"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

Sorry but it doesn't steal any top end power ... I had no signs of power dropping off up top thats for sure... Yes a clutch set up to disengage the S/C after what ever Boost or RPM would be an ideal set up and there are ways of doing this and I have seen it been done on a Civic, but I never had an issue so I didn't both setting it up like this.




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

Josh F wrote:Sorry but it doesn't steal any top end power ... I had no signs of power dropping off up top thats for sure..

i think he may be thinking that the turbo could provide more power alone at the top end.

example
twincharge=420 whp
turbo=450 whp

w/ just a turbo the power curve goes up higher, where the twincharge goes up just not as high


my carDomain updated 10/31/09 Forged and Supercharged

s1lver_N1p wrote:

Josh F wrote:Sorry but it doesn't steal any top end power ... I had no signs of power dropping off up top thats for sure..

i think he may be thinking that the turbo could provide more power alone at the top end.

example
twincharge=420 whp
turbo=450 whp

w/ just a turbo the power curve goes up higher, where the twincharge goes up just not as high

It doesn't work like that the super charger just multiples the boost from the turbo so you would make more power from a twin charge system then you would from the single turbo by its self at the same boost.This helps explain it i know it talks about V8s but it explains what happens when you twincharge with a roots style blower and a large turbo.

Edited 1 time(s). Last edited Thursday, November 19, 2009 4:21 PM

http://www.fquick.com/Caboose73

Roots blowers require power input just like a turbo...the faster they spin the more power they consume. This is BASIC physics. If you have an SC on there it will add parasitic drag on the belt. Even if you wanted to think "o the turbo will help push it" fine, think that if you want and to 'some degree this would be true, but that just means the turbo will supply the power, it doesn't mean the TOTAL power required to turn the SC has lowered. It's just that some of this power loss is now sent over to the turbo having to push harder to get the same flow and a little less drag on the serpentine belt then if the turbo wasn't there. The SC DOES ROB POWER up top.......PHYSICS. Deal with it, it's reality, you can't have something for nothing.

The energy to turn the rotors is coming from somewhere. The only way to quantify what your SC system is doing up top is you would need to know belt tension before SC pulley and tension after, this would give you crank power input to the SC, then use the known energy input required to turn the rotors as per the manufacturer and compare that to pre and post SC pressure.

Unless you did this, which I'm 99.999% sure you didn't you have no clue what the SC is doing up top. One simpler way to tell is find out at what RPM the SC becomes a drain rather than a help. All you would have to do is tap the SC's exit runner and install a boost gauge, then install another boost gauge pre-sc. Once these equal, or reverse, the SC is robbing you. Actually just before they are equal it is already robbing you due to the rotor energy requirements and increased IAT's.

If you can shift gears and properly design a turbo setup, a twin setup is a waste. (+weight,+IAT's, -Power, +$) > Twin setup benefits < worth it




Edited 2 time(s). Last edited Friday, November 20, 2009 11:11 AM

"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

Yes it takes power, but you are making it seem like it robs HUGE amounts. It is only around 9-10hp at its peak that it robs.. that’s nothing to be concerned about

ahah added weight? lol the supercharger set up adds what 15lbs? Yep that’s defiantly a deal breaker... I forgot all jbodys are racing for that 0.01 of a second.

IAT's as I said I wasn’t running any higher temps then a turbo set up but then I was running the stock 2.8" pulley as well as a 3" pulley. So intake temps we not an issue for me. Not at the power levels I was at anyway

this set up costs about $2,000 more than a turbo kit. that’s not that much more if you ask me when you can go with a large standard bearing turbo which is about $700 (what I paid for mine) vs paying for a $1,500 dual ball bearing turbo for faster spool up.. So really you are only spending another $1,200 (aprox) more than a turbo set up.




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

Josh F wrote:Yes it takes power, but you are making it seem like it robs HUGE amounts. It is only around 9-10hp at its peak that it robs.. that’s nothing to be concerned about

You are loosing ALOT more than the 9-10hp you think. Those chargers have a parasitic loss of ~25hp just to turn them once the engine is near the top end according to the MP graphs, MP says your charger can require as much as 40hp with a small pulley. Not to mention the added back pressure on the turbo at the top end. I think the losses up top are quite a bit more than you think.

Josh F wrote:ahah added weight? lol the supercharger set up adds what 15lbs? Yep that’s defiantly a deal breaker... I forgot all jbodys are racing for that 0.01 of a second.

LOL....umm...I think you got me wrong there. I just don't see the point in paying more and getting less, that is all.


"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

This explains why the super charger doesn't act like a restriction its from this article if you read the entire thing it explains alot about a twin charge set up and how it works.

A positive displacement supercharger when properly driven by the crank just gulps a fixed volume per revolution of whatever air density is there, and passes it to the output port. The boost pressure rises because the supercharger pumps a greater volume of air than the engine could otherwise inhale by itself. The supercharger can never be restrictive while a positive boost pressure is being produced.

If the incoming air density to the supercharger doubles, the supercharger mass flow will also double, and so will the torque required to drive the supercharger. Interestingly the supercharger pressure ratio stays about the same because the supercharger displacement and engine displacement (per revolution) maintain the same set drive belt ratio relationship. The flow through both supercharger and engine increases due to the turbocharger increasing the incoming air density to the supercharger.

There is a fairly widespread and seemingly immortal urban myth, that once the turbo winds up, the supercharger will become restrictive. That can never be the case if the boost pressure at the outlet of the supercharger is higher than at the supercharger inlet pressure. It can never be restricting the flow if that is the case.

As explained in an earlier post, the measured pressure increase across the supercharger actually increases fairly dramatically when the turbo begins producing more dense incoming air for the supercharger to work from. There is no question of there ever being a flow restriction by the supercharger.

If a supercharger operates at one atmosphere, or 14 psi absolute intake pressure, and has a pressure ratio of 1.5, the output pressure will one and a half atmospheres, or 21 psi absolute (creating 7psi boost)

But if the supercharger intake is operating forced up to two atmospheres, or 28 psi absolute, the pressure ratio of 1.5 still holds. That is the supercharger will have increased the incoming two atmospheres pressure up to three atmospheres or 42 psi absolute, or create a 14 psi boost increase, not the original extra 7 psi increase.

As the turbo winds up, the additional supercharger added boost pressure also increases as well. That can hardly be called restrictive.

http://www.fquick.com/Caboose73

I see your point, and you are right. But the simple crutch of the system still exists...it steals from the top and gives to the bottom.

My simple point is this, if a turbo can give you the boost needed and with a big enough power band to match the gearing...EVERYTHING ELSE IS A WASTE. I don't understand why people don't get that? It's a pretty @!#$ simple concept. If the motor can only hold 20psi and the turbo can push 25psi...why the @!#$ do you need a supercharger to waste money, increase IATs, add weight, and waste power?

If you plan on designing a system that uses the added boost from your supercharger all the way to redline(which is possible as you exsplain), you will have a small turbo in use and really wont need the SC to help kick-off. If a larger turbo setup could use the kick-off but still lines up into the gears well and the turbo can produce all the pressure your motor could hold back, you will be sending more gasses thru the wastegate then if you took off the SC and ran without. - This is my point.

With the turbo options available today, you don't need the SC. Pretty plain and simple. You can push more air with a turbo alone than the engine can hold back. The SC can help but in tandem with a smaller turbo and you will still have more total losses due to the rotating mass of the SC. Again, paying more and getting less. The point?



Edited 1 time(s). Last edited Monday, November 23, 2009 6:33 PM

"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

I see your point if your starting from scratch it doesnt make much sense to go out and buy a turbo and a s/c and throw it on your forged engine.But if you already have a M62 or even the MP45 you can just buy a decent sized non bb turbo for cheap and add it on to get more boost/power that you would probably get with a bigger bb turbo like the 35r.

This setup isn't as bad as you make it sound the weight is not that much take out your spare tire and jack to cancel out adding the charger and the IATs might be a problem if you were using the MP45 sense it has no cooling options but most of the time with a twin charge system your not spinning the blower with a very small pulley cause you dont need alot of boost out of the charger its only job is to multiply the boost from the turbo so a stock or even a bigger pulley to slow the charger down can be used.

http://www.fquick.com/Caboose73

^I for the most part agree from more of a compromising position. However, don't forget that a properly done turbo system will always put down better #'s @ Xpsi than a twin setup since it doesn't have to waste power turning the SC. People need to remember this. Also, by the time you rig up a inter-cooled MP62 you will add a good amount of weight and cost too so don't just magically list that like "O..problem solved" type of deal. Other problems that I listed as the issue will quickly rise....there's no getting around it.


"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

Everytime i hear twincharge i think of that titantic song. Cause it just goes on and on and never stops. I do agree that it has its advantages that far outweight disadvantages. Which is that it might weigh 100lbs more, so if you ever had a model in your car and it felt slower you dont want the twincharge anyway. Anyone ever ride a dirtbike here? Anyone felt the difference in a four-stroke and a two-stroke? Anyone see two-strokes being built?

/ thread please

Ummm......ok^...huh?...wtf?...I hope you were drunk when you wrote that...lol.


"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

Joshua Dearman wrote:Ummm......ok^...huh?...wtf?...I hope you were drunk when you wrote that...lol.

And i would be drunk why? Have you personally felt the difference in said dirt-bikes? If not let me put this in perspective. Two-strokes used to be the only thing raced. They had a peaky power band, much like a big-turbo setup. But then came along good four-stroke motors that acually produced torque below the peak horsepower. And now thats the only thing they make. Point is its not all about peak horsepower numbers for everybody. The twincharge setup works, and for some reason some people refuse to reconize it.

And how the hell can you argue the fact that a twincharge weighs to much? What could it be 100lbs? really? So does that mean that a twin-turbo viper that makes 1200+ horsepower is a waste of a set-up cause it has the extra wieght on it? Come on man.

Look, i'm just trying to help others that may not know any different about the draw backs of the system, nothing more. I'm not here trying to make people take them off or tell them they don't work. If somebody decides they want the instant throttle response and don't care about total power loss, fine, that's a decision they can make for themselves.

One thing is for sure, all drawbacks I listed are true and exist. You can run your mouth trying to be-little the honest truth to the point that you convince yourself and possibly others than it matters little, fine, free country, but the facts remain. SC's don't turn themselves, they don't lower intake temp, they do cost money, they do add weight, they do lower top end power. <-ALL FACTS, deal with it.

Anyway, this pissing match has gone on long enough, I've made my points which are not false, and have not been proven false. I haven't even heard the one argument that makes the most sense out of you TwinC guys...."The losses are worth the benefit, to each his own" - That is the only way one could argue. So far you guys have argued that I'm wrong...when I'm not. I haven't not once argued that the low end power exists, I know it does. On a windy road course a TwinC setup would definitely be STRONG competition for sure. My personal opinion, I'd like to see a centrifugal charger on an AC clutch with electronic diverter valves on the intake, when not in use the SC is bypassed. This would achieve all the benefits, without most all losses. I'm guessing you guys never enough thought of that either eh? I'm not a hater of the idea, I just don't like mis-information and false claims.

So there ya go, I've given you guys the only good argument, and a few good ideas....now please use them and stop trying to convince yourself and others that the losses aren't there. It makes threads like this. If you would stop at post two and say: "The losses are worth the benefit, to each his own"....the thread would stop. So should this one.






Edited 2 time(s). Last edited Wednesday, November 25, 2009 6:58 AM

"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous

Josh F wrote:But this Brian guy making 437whp @17psi... what dyno was this on, what gas was he running etc.... I can almost guaranty you he was running 91 octane because there would be no way a 2.4L could push 437whp on 91 unless he was just dumping in alky with an alky injection system.

Well first we have Brians old bottom end, turbo, and mani. Most of the other stuff we have changed. And i can tell you this, our runs were on 91 octane with stock ignition. Why, because thats the highest we can get about here. NO ALKY. The runs were done on a dyno dynamics dyno. Here is the dyno graph.



Thats with a very conservative tune. 11* of total timing advance. Would have tried to get more but the wastegate spring was too small...

All i can say is once you drive a cav with a gt35 pushing 20 psi, you will say screw the supercharger!