Indeed... a video with good audio of the jrsc->turbo transition would rock my socks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dustin &raquo;</TD></TR><TR><TD CLASS="quote">Indeed... a video with good audio of the jrsc-&gt;turbo transition would rock my socks.</TD></TR></TABLE>

Dyno video is on the first page, I'll have to do an in-car video.

 

Made a few changes, redid the bypass actuator assembly so it opens all the way now and uses no zip-ties, also built a throttle bracket onto the assembly so my throttle cable isn't zip-tied to the fuel rail pulse damper.

It was still building boost inconsistently, sometimes really fast, sometimes dog slow, so I set up a test bench with some air and a few valves and regulators to simulate operation under load. I figured out the problem, my analog feedback loop was a total POS and it was causing the diverter assembly to only partially open, and at the wrong time. I put together a digital feedback loop to control the diverter tonight and it works much better now. It builds boost much faster and every pull is exactly the same. The car feels much faster. The transition is not as smooth, although I still can't feel it on the butt-dyno, but if I watch the boost gauge then I can see the switchover. I'll try to get it on the dyno in the next day or two and see what kind of difference it made.

 

are you doing this on the AEM using one of the programmable outputs or did you use some other electronics? This sounds like a fun challenge to me - you could probably address it fairly easily using and extra MAP sensor (or maybe two) and a MCU to drive a PWM output so that you could maintain the seamlessness of your analog control loop and the precision of the new digital system.

 

Later I will probably run it all from the AEM, but for now I just used a Hobbs switch, a boost control relay off of an old 2-stage MBC I had laying around, and a small bleeder hole in a brass coupler, kind of a HMT version of an electronic boost controller.

 

damn this is unique as hell...

can you say... SUPER TURBO!?

 

I'll make sure if I run into you to give you a run(or at least try)lol...good job with the dual setup

 

The ideal situation (that I can envision):
-Second MAP sensor on charge pipe between turbo and supercharger
-Unused analog input on AEM
-Unused PWM capable output on AEM
-increase duty cycle to bypass solenoid as pressure increases - 100% duty cycle when turbo fully spooled for 100% bypass
-tweak shape of PWM curve to ensure smooth transition

I've yet to play with the programmable outputs on the AEM - don't know how flexible they are. Perhaps Jdogg or some other AEM expert could speak up? If this is beyond the capacity of the AEM, you could do it with an AVR or a PIC for peanuts.

 

yeah, blundar thats pretty much how it would work

 

VERY NICE man........great idea, excellent execution

Please post driving vids!!


Modified by LeGeND4LiFe at 2:56 PM 7/28/2005

 

I just have to say... a very nicely executed setup for an idea I only had brewing in the back of my mind at one point.

 

Incredibly inspiring....

I'm completely lost.... but damn it's interesting as hell to try and grasp any of it....

 

any new dyno results? love this setup

 

nice

 

I got it on the dyno again yesterday. WHP is pretty much the same at 355 (probably more, but that was about the tenth pull and it was hot as hell, so I'm sure we lost some power there), but the diverter assembly works much better now and the car feels stronger. I didn't save the results, but I think that it is spooling up faster now that I changed the bypass valve controller, I seem to remember hitting full boost (peak torque) around 4000 RPM. We (JDogg and I) tried adjusting the cam timing and changing the VTEC engagement point, but never picked up any power from it, so we just left the cams at the stock setting and set VTEC at around 4000 RPM (after the turbo is fully spooled).

I've been beating the hell out of it for over a month now (it's my daily driver, actually it's my only car) and it looks like the setup is rock solid. We made a lot of pulls yesterday and it worked flawlessly, plus it is still unbelievably smooth in terms of power delivery and drivability. I'm going out tonight to test-n-tune at a local dragstrip to see what it will do in the 1/4 and I've got autocrosses on both Saturday and Sunday this weekend, which should be a lot of fun with this setup.

It could make more power, I've made over 400 WHP on this motor before, but I'm getting another motor built, this motor has less than 2000 miles on it, and I want to keep it in relatively new condition as I will be selling it shortly, so I'm keeping it &lt;20 PSI. We did turn up the boost a little on the dyno, and it responded well to more boost. Actually I think we're running less boost on it now than we were when we last time we had it on the dyno, and we're making the same power. Intake temps were lower too now that I fixed the bypass valve, and it was hotter yesterday than it was last time I had it on the dyno.

 

Beautiful, can't wait to see those timeslips. Please take some videos

 

Roger, did you can the high compression dart motor and switch back to this set up? Its not all that surprising your dominating a road course with a set up that makes so much power over a broad rpm band. Did you smoke your brother’s m3? I bet that pissed him off.

 

got to stick my nose in here....


my old boss is working on a similar setup for an AWD talon.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STREETWERKZ &raquo;</TD></TR><TR><TD CLASS="quote">got to stick my nose in here....


my old boss is working on a similar setup for an AWD talon. </TD></TR></TABLE>

bumping it back up because i'm on the phone with him right now.

 

at request from a friend, i decided to post this for RMCDANIELS or anyone else who is willing to shed light on the subject.

Hi Roger,
My name is Chris and I just finished reading your posts on Honda Tech. First a little about what I am trying to accomplish. I own a 90 eagle talon awd. I am currently building up the engine, trans. etc., and plan on building a compound setup like you. I have already purchased an eaton 90 c.i. (off of a Ford tbird supercoupe) and I have determined that everything is going to fit fine. I have one big question for you to see if you have thought of the same thing that is bugging me. (no restless nights yet but who knows) I completely understand the purpose and function of the stock Eaton bypass valve, but here is where I don't think it will funtion properly in a compund setup. (please prove me wrong because life would be much simpler if I could get away from fabricating a electromagnetic clutch) On a stock o.e. style setup ( i.e. tbird supercoupe , trd truck kits, Pontiac Grand Prix etc.) at part throttle, or at cruise, the bypass opens allowing no boost to be built in the intake plenum and hence the Eaton roots supercharger is allowed to "freewheel" (still with rotors spinning because the belt is still turning) with very minimal parasitic losses. Now in your application ( and hopefully soon mine) when you decide to bypass your supercharger with the turbo up to speed you intake plenum is now positivley charged. I can't see how, with the intake plenum under boost how the supercharger acutually is NOT seeing pressurized air weather in the inlet or at the discharge. I don't see ( at least in a compund setup) without a use of a clutch that the supercharger is completly out of loop and causing parasitic losses. I know ( can't remember where) i have seen a dyno sheet on a Ford Tbird Supercoupe (stock) and the 90 c.i. unit on that motor draws upwards of 50 H.P. to drive that unit at full boost. Now I know we could do better then that with an Opcon, Autorotor, or any Lysholm compressor, but I got my Eaton for $275.00 in perfect used condition, and parasitic losses don't make a whole lot of difference on a roadcourse when the tourqe is instant and the turbo will be right around the corner and the supercharger is turned off. I have everything else figured out.....electronics, intercooler, bypass, and even a clutch, but if I am wrong ( I hope I am) It will make my project much..much easier and inexpensive. I have talked to Gerry at Magnusen (once) and he suggested using the bypass but I thought about the pressurized manifold and bypass after I got off the phone with him and apparently he is hard to get ahold of usually. I wan't to talk to Gerry only beacause he is a wealth of info. I know he built his own superchargers back in the day, and he was really nice and gave me a bunch of info, but alas I haven't been able to talk directly to him since. Anyways thats my rant, kudos to you for finishing your honda (I work for Honda and would have preferred to do this on one but with traction issues forseen) and thanks for listening,
Yours Truly
Chris Martino

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STREETWERKZ &raquo;</TD></TR><TR><TD CLASS="quote">at request from a friend, i decided to post this for RMCDANIELS or anyone else who is willing to shed light on the subject.

</TD></TR></TABLE>

I got Chris's e-mail and got back to him about it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rmcdaniels &raquo;</TD></TR><TR><TD CLASS="quote">

I got Chris's e-mail and got back to him about it.</TD></TR></TABLE>


awesome...... i would like to know too.

(although i am not building a twin-charger system.... its very fascinating)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STREETWERKZ &raquo;</TD></TR><TR><TD CLASS="quote">


awesome...... i would like to know too.

(although i am not building a twin-charger system.... its very fascinating) </TD></TR></TABLE>

Here you go..........

It has to do with how a Roots blower works. Unlike a Lysholm compressor that compresses the air between the rotors, the Eaton compresses air externally in the plenum. It’s really a “blower” instead of an actual compressor. So on an Eaton blower, if you do something that equalizes the pressure between the inlet and outlet ports (like opening a big bypass valve) the blower stops doing any work, so it stops taking much power to spin, and it stops generating as much heat, because it can’t compress air unless it has a sealed plenum to push the air into. So whenever the bypass is open, it doesn’t matter if I have the whole system pressurized to 20 PSI with a turbo, the blower sees no pressure because it has no sealed chamber to make pressure in and it can’t make pressure inside the blower because it’s just a blower. Your parasitic losses with a big bypass valve (I use a 2.5” valve now) should be around 1 HP with the valve open. I thought about building a clutch or using one off of a Mercedes, but I talked with a Mercedes tech that told me it wouldn’t be good for track use. They program them on a Mercedes not to engage if the motor is already revving very high, or it would destroy the clutch, and when I hit the gas I want some boost, no matter what RPM I am at.

 

i bet he was very glad to hear this!!!!!!

 

incredible