Apparently he new how to set it up or something about the blower tendency has been better adapted. Rather then speculate, I'd like to know.

I'm not trying to spread rumors, I'm just stating what my friends experience was with the Jackson roots on a Civic SI. He wasn't just some dip that didn't know what he was doing or talking about. He understood fully what the strengths and weaknesses were with the roots blowers and made the poor choice to make it work with some success, and through some inovation as well, as I mentioned earlier. We all want a fat tq curve but that doesn't mean it won't be at the expense of something or has draw backs. We have the worst platform to work from for this attribute, so I'd like to know what kind of effort and tuning has been done now to make it perform? I'm just trying to get some info from someone on here that knows more in depth how these work with our cars, which is proving to be difficult. I will take a look at the links you provided. Thank you for those.

Man, I just think If you are running a serious piece of hardware like this on your car, I would expect that person to understand what it is doing and how it is set up. I'm a hands on guy, I do all my tuning and work from suspension to body, i'm a believer in at least being involved in the install process even if you don't do all the work just for your own future trouble shooting and save some $$. I don't just plop down a pile of money to a tuner shop and say put this on my car and make it work, sorry. Would be nice if there were more doers and less spenders, if you know what I mean? peace

 

I hear you about the doers and spenders --
I've always done my own work..
there is something nice about looking at a freshly painted car (or blown motor) and thinking I did that ---

from reading MugenRioS2k , Neptuner and Wlaurents posts, I think they all know that difference too.



There is a lot of info both here and at SOT



I still don't see why your friend would think a high reving Vtec motor would have problems w/ detonation --

I would think the low rpm lobes would make the motor react like a low reving non vtec with regards to detonation. even w/out something to lower the compression ratio or raising the A/F.

maybe he was using low octane fuel?

 

What gen blower was your buddies civic using?
Was it a cold side or a hot side blower and was it intercooled?
And what approx boost was he attempting to run?
Was he using the base tune/ base pressure supplied by JR or was it modified in some way?


Theses are all questions that will point as to why he was having problems.


Not knowing more at this time my guess is something was modified (tune or boost) and there was not enough aftercooling to keep IATs in check; hence the need for water meth injection.


The newest version of the blower has changes in the rotor design and outlet profiles; this allows an increase in max rotation speed (as defined by the manufacture) increased the efficiency and smoothed out the outlet flow. Way back in the early days roots actual pushed out air in pulses over the many years of advancement those pulses have all but been removed and the current outlet flow is all but a continuous stream of air.

Not seeing exactly how your friend had his car set up I can not tell you why he was having such a problem. Perhaps the blower that JR was using was just to big for the application.

I think the key thing here to realize is that the SOT setup is working very well and is a dream to drive the S with all this extra TQ under the curve.

 

Good info guys, this is more what I was looking for. I'm going to colaborate with my buddy again and figure a little more about why the issues he was having were so prominent. My geuss is the Jackson wasn't as refined as it is now compared to 5+ years ago and neither were some of the tuning components. It came off a Mustang, which is what these were used for at the time. Developing a automatic servo controlled boost controler to allow for a slower boost curve, water enjection, along with many safeguards to protect from leaning resulting from quick throttle applications were all tuning measures that were taken at the time. It was expensive,time consuming and hardly a out of the box slap it on painless install which it sounds to be now days. He was only able to push 230whp out of the 99 Si civic with this set up. He daily drove it on 10psi and ajusted boost control for 14psi to race. He did have a fat torq curve.

As you can emagine i was so turned off listening to his experience with this set up that I haven't even considered it. I do like the idea however and am interested in learning more about what is involved now to building a reliable set up.

What are typical daily driver set ups making tq/hp? And what it the cost compared to the alternative FI set ups?

 

There is an inherent problem with just venting/recycling the outlet flow to pressure regulate it down to 10psi when the blower is putting out enough flow to =14psi.

What blower was this MP62. MP90 MP112?


I am assuming that the pulley were not change from the previous application which is why you were getting 14psi if the system was unregulated using the bypass valve you described.


The blower is going to add a set amount of heat (work) to the outlet charge ( increased heat as pressure increases) by venting the pressure back to the inlet the amount of heat gained due to compression is not being reduced that heat is still in the charge air and will still make it into the motor unless ICed or cooled by water/meth.

+ there is now an additional big problem that you are now contamination the inlet air with hot air which drives the outlet temperatures up even more. It becomes a cascading effect.

A better engineering approach would be to vent the Hot air (pre IC or pre water meth) to ambient by using a Wastegate device. This way the incoming air is not pre heated. The air charge making it to the motor would still need to be Iced or water/meth injected as that charge still has the work generated heat.


Based on that info it sound like he was trying to overrun the blower (assuming MP62) to get the 14psi.

The earley Eaton/Magnson blowers were only designed to run about 6psi non ICed and 12psi Iced due to there efficiency ratings depending on model and application.
With the advances in technology those pressure numbers have increased over time.



Picking the right supercharger and running it in the correct zone is just as important and parallels picking the right turbo and running that turbo in its maximum efficiency range.

 

how did he have boost control on his JRSC??? i never knew about this other than changing out the pulley...


wouldnt "high revving" not have anything to do with detonation? i thought it was all in your ignition timing and amount of heat produced created by our high compression...

 

This is the only type of FI I would ever consider running, hopefully it works out well.

 

Basically look it as a pop off valve or over pressure check valve.


FYI pop off and a BOV are two different applications of almost the same hardware.

Changing the pulley on a belt driven supercharger is the proper way to control boost pressure on a belt driven compressor.

I have another idea on how to control boost but that idea is patentable and I do not want to let the cat out of the bag just yet.




you are correct

 

I discussed some things with my friend and got scolded for mentioning th boost device that was invented. Some issues revovling around that topic I shouldn't be getting involved with.

 

[QUOTE=MugenRioS2k,Jan 23 2008, 08:33 AM] There is an inherent problem with just venting/recycling the outlet flow to pressure regulate it down to 10psi when the blower is putting out enough flow to =14psi.

What blower was this MP62. MP90 MP112?


I am assuming that the pulley were not change from the previous application which is why you were getting 14psi if the system was unregulated using the bypass valve you described.


The blower is going to add a set amount of heat (work) to the outlet charge ( increased heat as pressure increases) by venting the pressure back to the inlet the amount of heat gained due to compression is not being reduced that heat is still in the charge air and will still make it into the motor unless ICed or cooled by water/meth.

+ there is now an additional big problem that you are now contamination the inlet air with hot air which drives the outlet temperatures up even more.