user_name

Yea, I'm being over the top considering all of his comments above. You will be super polite if I insult you if/when we meet in person? You are nicer than me!

I stand by what I said. His results are lackluster. It's not going to translate to any kind of wins. A wastegate is a wastegate and will bleed off boost as mentioned. That boost curve is not what I would want out of it, and the hell with trying to tune it. Would be messy.

bradenW

I can't remember the last time someone insulted me in person, so I wouldn't know.

I believe his comments were made after you continued to return to bash the his setup. You made your point that you don't like it. That's cool, everyone has an opinion and you're certainly entitled to yours. IF/when he does upgrade the internals on his motor, his setup will be ready to rock & roll so kudos for doing the way he wanted it the first time. It's not what YOU want, it's what he wants.

DOUG @ ECS

Nice job builder your car how you like it.


Using a waste gate is very close to the same idea as our restrictor plates, and we have several cars out there running a waste gate. Most of them are very high HP cars with the point being for race gas/pump gas boost levels at a touch of a button, or for dialing the car in for index racing.
For index racing, the same car can enter into class' from say 8.50 to 10.50 with a touch of a button. Then the owner can follow the money races if he/she chooses without any problem, or at least adjust for the DA very quickly.

I am surprised that you do not have a steady boost level though, I am tuning a car in few minutes with a waste gate on it, the boost graph is as flat as any turbo car? If I have time I'll post up some results from it. The build is a Novi 2500 on a 416, at 14lbs he is still breaking out in the 10.5 index. It will make about 20-23lbs when the waste gate closed.

DOUG @ ECS

Cost and lack of necessity by most end users.

jbondfl

I lurk to learn. Lots of conflicting info here so I will interject only a few points.....

I'm pretty sure if you pulley down and add a cam you'll make more power on almost any car.

Since the purpose of a wastegate is to prevent boost above chosen levels I don't see any way the wastegate itself can actually ADD power. I can see how it can change where power is produced, but not actually ADD power. (yes, I'm aware that it allows a turbo to spool faster, but this isn't a turbo and it will spool only as fast as rpm rises)

If I wanted to show how much more power a wastegate made, or how it changed the curve, I would ONLY MAKE ONE CHANGE. Take out the restrictor plate and add the wastegate. Then I would know for certain exactly what gains were made from that mod and exactly how much those gains were.

Personally I think that is the only point that can/should be challenged. EVERYTHING else is conjecture, or oprinion, or a +/- based on how you intend to run the car.

I do like ingenuity though. We see 800hp+ out of these cars because someone is always trying something different.

96TTdodge

Hi,
Your correct. Adding just a wastegate and making no other changes would = zero results. For the purpose of this discussion you can basically forget about the final HP number, that is basically irrelevant. The idea is to create more/faster boost by throwing a smaller blower pulley on. - That would be the most simplistic way of yielding results with this setup.
Unfortunately I didn't invest the time or money in having the cam installed then dynoed.....then installing the wastegate and dynoed again with different pullies. That would have definitely been ideal for data comparison purposes.

96TTdodge

Hi Doug,

Can you comment on whether or not you see boost faster with a wastegate or restrictor plate?
This is the question everybody is dying to know.
My gut tells me that there is no way a maximized restrictor plate setup would achieve boost as quickly as say, an 8" overdrive pulley and 3" blower pulley with wastegate. (use 14 psi max for this example)
Butttt... who knows, maybe you'll surprise me.

96TTdodge

Hi and thanks for the kudos.
I 100% agree that the SC is spinning faster and that more spin = more stress on the supercharger. My point was that the wastegate itself isn't contributing to any of the "strain" your concerned with. Take the wastegate off and let it rip on forged shorty and the blower is still going to see the same amount of "strain". There is no additional strain that a traditional install caused by the wastegate.

blkdevl

finally a big name popped in and said it works maybee some haters will shut there pie holes now.

i plan on doin the same thing when i go to a ysi so i can have 20# on race gas and 14# or so on pump.

95wht6spd

So a WG is operated by a boost controller to regulate boost?

4DRUSH

Yes

joshtownsend

Anybody want some pecan pie?? I'm going to the fridge right now.

4DRUSH

I'll take a Captain & coke if it's not much trouble.

Mister Peebody

Not always, but can be! In this set up, it is not on a boost controller.

Something else I think some people are missing is that you could not run the pulley combination you currently run to the RPM limit you currently run up to, if not for the wastegate. That pulley combination would more than likely destroy the stock pistons and/or rods.
So yes the pulley swap on any FI setup would make more power, but you couldn't do the pulley swap without the wastegate.

Warp Factor

Some potential advantages from using a restrictor plate in front of the blower, rather than bleeding boost on the output side:

The blower won't be working as hard, because it will be compressing less air. With the boost controller, you're doing the work of compressing the air, only to waste it by releasing it.

Potentially lower air temps. The wastegated setup takes air at ambient temperature, and then compresses it. The restrictor plate setup has a pressure drop in front of the blower (which will cause a temperature drop), and then compresses that cooler air. The blower may need to compress that cooler air more, but won't need to compress as much of it.

Ideally, someone might come up with a variable restrictor setup, perhaps made from an electrically controlled throttle body attached in front of the blower. It could be wide open at low rpms, and closed as needed at higher rpms to maintain a set boost level.

Turbo-Geist

I'll applaud you for taking the time to log some data and having a shop install a boost control device to work with your supercharger. I've never been one to try and limit the power that my car is making but I can see the reasons behind it.

Other people have also stated that the big benefit comes with the adjustability that it can provide for a supercharged application at higher power levels.

I think the main issue is with your first post. For people skimming over the data, it kind of reads like all of your power gains were due to the wastegate. You pullied down, went speed density installed a cam, etc. These are the reasons for your power gains. Without the wastegate, your peak boost would probably be atleast 16 psi. The gains in the midrange are solely due to the performance modifications that were made and would be the same with or without the wastegate up to about 10 psi.

96TTdodge

I have to respectfully disagree with this statement. The bottom line is that if you want FASTER boost at a certain RPM you will need to pulley down no matter what. PERIOD. End of story. A restrictor plate isn't going to produce more boost without pulley'ing down also. In other words, if you want 10psi at 4k rpm (for example) you will need the same pulley setup to accomplish it. There is absolutely no FASTER way to make boost than simply running a smaller pulley. A restrictor plate has zero advantages other than cost when compared apples to apples. None.
I do agree that the excess compressed air is being "wasted". That was mentioned several posts back. With meth I think this point is nearly a moot point personally, but that is just my opinion. The SC is designed to spin what I'm spinning it....soooo let it spin I say!!
First of all, thanks for the kudos! I like to play and try new things when I have the time. My apologies if my first post wasn't clear. I thought I made it pretty clear that other mods were installed....they're even listed in bullet point fashion I believe. Owell. Anywho, I also have to disagree with your comment that the power gains are solely due to the performance modifications. (cam, speed density) First of all, I think it is painfully obvious that you must change pullies to make more boost AND yes, the wastegate without the pullies would be worthless. - That has been said about 17 times now 13 different ways. HOWEVER, take the cam and other things out of the equation and there are still significant gains midrange to be had by JUST the wastegate and pullies. There is absolutely no way to argue this for anybody that fully understands how this works. Its almost comical at this point that we're back to "Boost 101 class". There is absolutely no faster way to make boost than this and as we all know, (hopefully) more boost FASTER equals more power under the curve. Is a restrictory plate a close 2nd option?? Yes, without a doubt..but this is the best option. Game Over. (of course a forged shorty etc is even better... then you just let it rip and F' the wastegate)
Here are two links with superchargers and wastegate. The midrange gains are very clear to me.

http://www.musclemustangfastfords.co...l/viewall.html - this is a great example of what ECS was explaining on their bracket cars - for the adjustability aspect.
http://www.gmhightechperformance.com...ate/index.html - this is a perfect example of what I'm trying to explain.

Sorry guys, please don't take my posts as "hate" or argumentative. I'm all for a "clean/professional" fact-finding discussion. Hopefully we can keep it on track. I just refuse to allow incorrect information in my thread. Real facts vs opinions. Thats one thing I can't stand on any forum. People constantly post incorrect information and nobody corrects them, which leaves the next person to read it (who is trying to learn) confused and uninformed.


p.s. Ultimately, I'd still like to see boost data for somebody with a restrictor plate setup on a Novi 2000 and ECS small cam at about 14 psi. 943 views in a forced induction forum and nobody with this data amazes me.

pianoprodigy

This really doesn't seem like a difficult concept to me, but perhaps that is because I have pondered it quite a bit prior to this discussion. Let me try to give my thoughts in the most concise way possible. Initially, I’ll speak generally and then address OP directly.

Assuming a blower is not vastly undersized for the application, a good rule of thumb to use is that a centrifugal blower will flow half of its pullied volume of air (and consequently realize half of peak boost) at 2/3 of the RPM for which it is pullied. In other words, if your pulley makes 10 PSI at a redline of 6,000 RPM, it will make 5 psi at 4,000 RPM. If your redline is 6500 and you are pullied for 12 PSI peak, then you would make 6 psi at 4,333 RPM. Here are a few dyno charts for example that actually logged boost: http://i226.photobucket.com/albums/d...008C6dyno1.jpg http://shop.brutespeed.com/media/dyno%20graph.jpg http://i176.photobucket.com/albums/w...ildDynoSAE.jpg

The goal of using a "wastegate" to bleed off boost from the charge piping in the upper RPM range is to use a pulley that has a substantially higher peak boost number so that you would get to whatever max boost you want to achieve as early as possible in the rev range to create cylinder pressure resulting in torque and horsepower.

If you do not want to exceed 12 psi on a particular setup, it would not make sense to only slightly increase potential max boost to 13 or 14 psi because the effort involved would not be worth the gains potentially realized. It would make far more sense to change your pulley ratio to something much closer to the max RPM of the blower (which is likely where it is most efficient anyways). This might result in 24 psi at redline (or more if you had a capable blower) if left unchecked which may not be desirable; however, using the above-captioned rule of thumb, if 24 psi occurs at 6,000 RPM, then 12 psi will occur at 4,000 RPM. After 4,000 RPM, the wastegate (as controlled by some type of boost controller, more on that below) will begin to gradually open and bleed boost from the charge pipe and maintain 12 psi all the way to redline.

It should be clearly evident that making 12 psi from 4,000-6,000 and consequently an average of 12 psi will result in far more average horsepower than making 6-12 psi over the same rev range (and consequently an average of 9 psi). Of course, the gains beneath 4,000 also cannot be ignored and would also be dramatic since the ramp rate of the boost will be roughly twice as fast using my example.

The blower will undoubtedly require more horsepower to be spun and will surely generate more heat, but not as much as if 24 psi were actually held in the charge tubing rather than being vented to achieve a max boost of 12 psi. I would plan on using an Alkycontrol kit anyways, so the charge temps would not particularly bother me either way as they would be easily corrected.

OP: I would strongly recommend at least getting a manual boost controller which will prevent if not eliminate the wastegate from creeping open early since a 12 psi spring will usually begin to open about half of the max pressure resulting in a loss of response. How dramatic? Perhaps not much, but a decent manual boost controller is $40 and takes all of 2 minutes to install.

When I get around to implementing this strategy, I will likely use an electronic boost controller (EBC) to keep the wastegate shut until the last possible minute without creating too much of a boost spike. This should result in maximum response from a given pulley setup.

My other purpose in using an EBC rather than an MBC is using the failsafe trigger on my new AEM Wideband Failsafe Gauge that has yet to arrive since it was just recently released. If it senses an AFR that you have defined as being “unsafe” at a particular boost level, it can send a signal which can trigger the boost controller to revert to spring pressure, dumping boost, going pig rich, and potentially saving the motor. I am running an F1R on an SBC than I’m only turning to 6,000, so I have more than enough cfm (2,000 max) to play with this and benefit from it.

96TTdodge

Pianoprodigy - Good thoughts. Well said and thank you!
As Doug had mentioned in his post, my wastegate spring pressure alone SHOULD be working correctly and holding solid. I spoke with Precision Turbo yesterday and am working with them to figure out what the problem is. I may have a "defective" wastegate. I pulled it off last night, but didn't have time to bench test it yet. I do have a brand new electronic boost controller that I never used on another car and a used manual boost controller sitting around.
First I need to figure out the wastegate problem and then I may throw the manual on. I personally would only go electronic if I was running big boost and wanted to make precise changes.

LinearX

No question there. Good luck with it!