Mr.Big

His numbers are much higher than mine his 832 to my 761

sciff5

iTrader: (1)

his high boost numbers are not whats relevent because in high boost mode its as if he doesnt have a wastegate at all. In high boost his setup is just like any other 800+whp supercharged setup

I am trying to see how much area under the curve you gain in the low boost mode that is what this thread is about and you'll notice even in low boost, even though hes making less peak power than you hes making more area under the curve still from 4k-5500rpm and I would assume the difference would be bigger under 4000 rpm as well.

Thats the reason we're looking at using a waste gate, to boost low and midrange and create more area under the curve overall.

Mr.Big

I more than understand the thread and have done tons of R and D on this one... just correcting the statement out of respect for his results...

sciff5

iTrader: (1)

Gotcha, now I'm on the same page with yah

will01

The op asked if there is a way to dial boost with a sc like a turbo, in reading the thread it appears the solutions are very discrete (meaning on or off; blow off valve bleeds extra boost once xx psi is achieved or restrictor plate that only allows xx psi).

Has anyone ever tried using a set-up that worked similar to a throttle body? If built correctly, an actuator or servo could drive the blade to offer more precision - variability, in releasing extra boost?



Would this work?

If this was discussed earlier please disregard this suggestion.

sciff5

iTrader: (1)

People always seem to bring up this idea in these threads.. and I think the biggest thing would just be the complexity of it. How would you control boost accuratly with it, and also what method would you use to actuate it?

jeejee

iTrader: (3)

it's not that impossible / difficult,
use a boost actuated bypass between the restrictorplate and the supercharger.
Which allows more air between the plate and superchager untill a predetermined boostpressure closes the extra air intake

with that you can even use an in car boostcontroller, to dial in the amount of boost you want

Awake455

My thought/concerns with bleeding off boost with a wastegate is that you are doing work to compress and blow air that you are not going to be using. This is going to make your airflow out of the supercharger higher...maybe tossing you into a different area of the pressure map, different efficiency range. It also means the supercharger is going to be robbing a bit more power than normal...moving that air you are bleeding off.

Also, this means more load on the head unit...and more load on the belt. This by itself may be no big deal if your belt setup can handle the extra load, but you are also going to be spinning the head unit faster...to get the higher boost numbers at lower rpms. One would have to keep head unit redlines in mind.

Bleeding off boost should and does work...but wouldn't it cost less power to throttle the inlet side...before you have done the work of compressing and moving the air?

Ponyhntr

iTrader: (9)

Very good (and VERY true) points!

EPP

iTrader: (22)

I agree, and the best method that I can see to do this would be with a variable clutch assembly on the blower that would allow the blower to be regulated to slow down. Obviously this would be very complex and expensive. Bob

Robert@G-Force

That not what Jim Summers at ProCharger said.

Mr.Big

Has Jim Summers at Procharger done this, and driven the cars??? Several of us have real world experience with this, for SEVERAL thousand miles, we're not just assuming on paper... People can speculate all they wish, but real world driving results matter, In my experience over boosting has done nothing bad (NO higher IAT's, no pre mature h.u. failures, no boost spikes, etc,etc,) but it has made VERY good power, and now with the waste gate/boost controller option, it offers higher hp guys traction, through boost by gear... what's the documented down side that anyone has actually logged through miles on the road, and races raced??? Don't knock it until YOU try it...

Ponyhntr

iTrader: (9)

As a matter of fact, he has.

EPP

iTrader: (22)

http://www.procharger.com/2003newsle...m.summers.html
http://www.procharger.com/racing-new...ng_may08.shtml
http://50mustangsuperfords.automotiv...ons/index.html

I would imagine that Jim Summers has tested them as he is very involved. Bob

Mr.Big

Bob,
Very nice links to race cars, but where are the cars even close to what we are driving/building, that show the street driven + race miles that we have proven with our setups... I'm sure Mr. Summers is a VERY respected racer, but these are street cars that we happen to race in this thread. And from many, many more miles of experience than he could ever accumulate with his race cars I can't find the negative in this setup from MY experiences... You know I respect what you say and contribute, but my experience on this topic shows no downside thus far... You must admit 761rw out of a little P1 isn't shabby... for me this is about boost by gear so I can get traction in the first 3 gears at the standing mile events... that's gigantic for my application... remember guys I'm at 30,000+ supercharged miles on this evolving setup, and the starting point was 620rw... so there is a slight amount of R&D on MY setup...

Ponyhntr

iTrader: (9)

It's great that it works for YOUR setup! It just won't work for EVERYONE's setup like you imply.

Taking shots at one of the most respected in the forced induction industry is pretty low. Bob was just trying to point out that Jim is not a NOBODY. Just because all the links talked about Jim's racing experience doesn't mean he doesn't have any 'street' experience. John Meany (creator of some of the most well-known aftermarket EFI systems out there, ie Big Stuff 3) was even quoted in a magazine article (forgive me, I don't remember the publication) saying that Jim was one of the best tuners in the country, street or strip.

Just because it's not on the internet doesn't mean that it hasn't been tried or tested by some of the industry leaders, whether it's Paxton, Vortech, ProCharger, or anybody else.

427

iTrader: (3)

I tried bleeding boost after the head unit to control high rpm boost but get better early boost. The bleed-off system worked perfect right up until the head unit failed. With the second unit it worked a little longer before the head unit failed. At that point I had been told twice, I figured out a new way. If you put the throttlebody before the supercharger it will take load off the supercharger for sure. My set-up would have worked fine for standing mile racing, but it was in a underpowered truck, in boost to often for the bleed off system.

Kurt

Mr.Big

Ponyhntr,
What are you talking about dude... please read BEFORE you post... I have MUCHO respect for Bob and EPP... please don't imply something false, and it's O.K. to disagree, and it's also O.K. to agree to disagree... sooo get your facts strait before you accuse please... Thanks...

Ponyhntr

iTrader: (9)

Maybe you should re-read. While Bob is very respectable in his own right, I was talking about Jim Summers!
Notice I repeatedly said 'Jim' in my post?

sciff5

iTrader: (1)

So we've heard everything from it works great to it kills your blower.

I PM'd NLR but havent heard anything back after about a week. I dont think he checks this board very often based on his post count