Twincharger v2.0 teaser...Photos inside

[RayPeters]

I've been selling these kits for awhile now

http://www.dsmtuners.com/classifieds/showproduct.php?product=56632&cat=7

If you want you can read all about it here.

http://www.dsmtuners.com/forums/showthread.php?t=241321

I'd PM you the info but maybe the others want to know.



Ray about the side mount your running, you just have the pipe going to the back of the intake mani right? What stops the S/C from going straight into the engine instead of the intercooler? There is no divider inside the intake mani correct?

The most difficult part of making the intake manifold is the divider. The SC outlet is sealed from the intake runners, IE it has to go through the SMIC, MAF and TB before it gets to the engine.

 

[LaN-]

The most difficult part of making the intake manifold is the divider. The SC outlet is sealed from the intake runners, IE it has to go through the SMIC, MAF and TB before it gets to the engine.

O ok, didn't think you had a divider.

 

[aero_sallee]

I'm not sure if this has been posted or not. I remember someone talking about the QTP being too slow.
If it seals with a BC controlling it it may have some use.

http://www.atpturbo.com/Merchant2/m...tp&Product_Code=ATP-ACS-010&Category_Code=BCS

 

[RayPeters]

Aero,
Thanks for the great link!! I had seen this type of valve back when I was working with my powerjoke but couldn't see why I would want it. Now it looks more interesting.

I've got room for that bugger too, but its out of production

 

[aero_sallee]

Aero,
Thanks for the great link!! I had seen this type of valve back when I was working with my powerjoke but couldn't see why I would want it. Now it looks more interesting.

I've got room for that bugger too, but its out of production

Hopefully they get those production issues fixed. I wonder about fabricating something like this with a WG actuator and the guts of a QTP or similar valve. My biggest worry would be effective sealing, but I guess if a throttle butterfly works this could be made to also.

 

[RayPeters]

I tried a throttle valve in my car a couple of weeks ago and found that it was very difficult to open it quickly enough to prevent huge pressure spikes in the intake piping. I'm searching for the right air cylinder as I write this, I need 15-20 lbs of force to get it open fast enough. Might drive it electrically too......

 

[Spyder4g64]

Awesome awesome awesome. Thats all that comes to mind.

 

[RayPeters]

Collective update for everyone. Last couple weeks I was fighting a knock issue after highway speeds for 20-30 min. A/C made it worse although water temps were fine.

Colder Plugs (from 85 rx7) helped a little, but after some temp measurements, it looks like heat soak of the secondary intercooler looked to be the problem. So I tore all the intercooling piping out, swapped the order the air flows through the intercoolers, and moved the bypass BEFORE the 2nd intercooler, I see no reason to cool the air that is headed out the bypass. So the flow order is now: air filter -> Turbo -> SMIC -> Supercharger -> Bypass Valve -> FMIC -> MAF -> TB. This also allowed me to neaten the pipe routing a bit as runs got shorter and more direct. (I do this a couple more times I think I can call myself a plumber)
Also moved the air filter away from the radiator fan and installed a heat shield to keep the filter area cooler.
With all that fun out of the way, the Rallycross is next Saturday http://www.johnsonvalleyrallyx.com/ so it was time to get the Hotbits fromt struts tuned and the skidplate installed. The skidplate helps the cooling. sealing the area between the bumber and the radiator support plus the flat bottom and venturi effect at the rear of the plate there is a noticable drop in water temp, enough that I may consider going back to a warmer thermostat.

A comment on something from an earlier post: The supercharger dowsn't stop when unclutched, if I run my car without the belt, the SC turns to allow the air to flow through. It adds some lag to the system, but overall power is decent, looking at airflow logs and fuel injector durations. It's down 10-15 %

A question for LaN, you posted a few pictures of the clutch for me, did you ever pull the bolt out of the center? I'd like to know how that thing goes on there and which shaft they are using. I'm headed in the clutch direction, but I want to put it on the SC as I already have the intake and I like my AC.

 

[eclipsh]

Nice to see the update Ray. Good call on moving the bypass. What size sidemount are you running? If it is stock, why not run a Supra SMIC or something similarly large?

It is nice to hear the SC is still spinning and doesn't get too much in the way. Gives me hope for following in your foot tracks.

Best of luck on the rally, or should I say break an axle?

 

[CrazyGSX]

a good setup is turbo to intercooler to tb to super to intake

 

[RayPeters]

a good setup is turbo to intercooler to tb to super to intake

If you look back through the newbie forum, I spent several months developing a system like this. It ended up ruining an engine from detonation. High intake temps. The SC stage must be intercooled to work here in these high temp parts of the country. For drag racing it might be possible to ice chill everything and not have issues, but for daily driving it didn't work to my satisfaction.

 

[VanIsleDSM]

I love the idea of having a car with no lag.. that's awesome.. great job by the way, I'm really happy to see things like this going on.

Now for a system that Lan was talking about a few pages ago that was just to spool the turbo.. which would retain more drivability I think... it would only work if you were running on MAP but you could have a very small SC using the smic with it's own seperate intake.. maybe 6psi.. use a 1.5" pipe and have it blow in through a check valve like this one

http://www.spadepot.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=BX9907&Category_Code=Pumps

or something better (just an example).. pipe it in at the TB elbow with the valve right there... this way the turbo couldn't send pressure back through the SC, once the turbo makes over 6 psi valve shuts and your SC turns off..

You could set the clutch on the SC to activate only at full throttle when RPM = 2000-3500 and when boost < 6psi (just making up some figures)

I can see why you would want to continue using the SC to re-boost the turbo even more but that probably starts to get into some stuff I don't want to deal with... like the heatsoaking and inefficiency of spinning the SC all the time... if you only use it for spool then during the time you're making the power you're still just a turbo car that everyone is fimilar with.. just got spooled by an SC is all.

I also thought of just using one of those electric ones for spooling, if there were any good ones out there? or maybe they're just all ebay specials.. I'm not sure on that... but an SC to provide ~6psi (1.4 p/r?) to a 2L engine only between ~2000-3500RPM wouldn't need to flow much.. I imagine it could be pretty small.

Anyway.. again, great work.. you've got a lot of people thinking.

 

[RayPeters]

That's an interesting idea still, I'll give that a little more thought and see what I can come up with, maybe get some flow calcs going......how do you propose to prevent air from backflowing from the SC into the turbo?

it would only work if you were running on MAP? Why? Just put the MAF at either end of the system. Easiest to do at the TB end. Only measure the air that enters the TB, all of that has to go through the engine.

 

[VanIsleDSM]

Hmm.. I tricked myself into thinking it would have to be MAP.. you're right, it would work just fine.. but yeah.. right back at square one.. I wasn't thinkng about the backflow to the turbo.. you could use a similar valve.. or an electrically triggered valve that turned on and off with the SC, but then you might aswell go with the VW solution if you're gonna have to have a valve that big anyway... I like they're idea too.. and it has the SC before the turbo, I somehow think that would help it spool better than just feeding the motor boost to make more exhaust pressure to spool the turbo.. you're be directly spooling it... and with the VW setup the SC doesn't become a resctriction later on.. so you don't need a big one at all.. that's what I want.. mostly turbo.. a hint of SC..

So I guess the basic difference in having the the Turbo and SC in a "Y" is you need 2 valves.. or SC before turbo.. you only need the one big valve to bypass the SC when it's done doing it's work.. so to still add a touch of my own thought I wouldn't have the SC draw from the same filter.. I'd just through another one right on the end of it.. elminate some plumbing.. and 2 intakes is obviously more cool than 1.

After I put the 50trim in and I'll start thinking seriously in this direction...

 

[T_K]

I'm not sure if this was posted already but here's the VW setup

http://bioage.typepad.com/.shared/image.html?/photos/uncategorized/tsi_airflow.png

 

[JOEY A]

Yeah so when this thing going to have a vid of it running and ripping up and down?


Thats cool to talk about all this, but I would like to see what this thing does


Post a vid in this damn thread! I REALLY WANT TO SEE IT!!!!!!!!!!!!

 

[dsm-onster]

Yeah so when this thing going to have a vid of it running and ripping up and down?


Thats cool to talk about all this, but I would like to see what this thing does


Post a vid in this damn thread! I REALLY WANT TO SEE IT!!!!!!!!!!!!

There's already a video posted in this very thread, Rallycross Vid. AND two in the other thread: Engine compartment video & Inside the Car.

 

[RayPeters]

Thanks DSM-onster. This weekend is the Rallycross so I'll be shooting some more videos. I'll try to get some cool stuff but it is hard to run with a camera mount in the car, it is a bit rougher than autocross.

 

[VanIsleDSM]

http://cgi.ebay.com/ebaymotors/Mini...tegoryZ33741QQihZ009QQitemZ190111159614QQrdZ1

Found that little guy while I was looking around.. 500CC/rev (30.5CI) what does that mean exactly? I know what it means.. but I was searching around looking for supercharger info to put a face to that figure but I couldn't find any more info on it.. I think the GM eaton 3800 SC is 1500CC/Rev (90CI)

This right?

30.5CI/rev x 15000rpm (max revs) = 457,500CI/minute MAX divide 12/12/12 (1728) = 264CFM


I've never run any form of engine management or done any tuning.. I've only had this DSM for not even a year and I never modded my other one.. I'm very adapt to math and science and such but I'm a hands on kind of guy so my head won't really get around all the numbers until I'm actually involved with using them..

At that time I can check out what my car if flowing from 2000-3000rpm and work out what drive ratio I'd need.. (and if that SC would do well for that range) I mean.. theoritcal but if I was flowing ~ 65CFM @2000rpm and ~98CFM @3000rpm (sound about right?) so 1.4PR (5.88psi at sea level) would mean I would want ~91CFM @2000rpm and ~137CFM @3000rpm?

If that is true then..

91CFM x 1728 (converto to CI) = 157,248/30.5 = 5155rpm on the SC so 2.578 drive ratio on the SC?

this would mean 7761rpm when the engine was at 3000rpm and produce 137CFM, well within that small SCs limits.. but I'd like to see a efficiency chart for it to know what was best.. also I'd prefer a screw type SC to a roots.. but hey I guess it doesn't matter much if it's gonna be that small.. that's all assuming I'm right here.. I could be way off... Like I said.. haven't jumped into any tuning yet.. but I will soon.


Edit: just found this http://cgi.ebay.com/ebaymotors/Acur...tegoryZ42604QQihZ005QQitemZ150120580830QQrdZ1

that's what I mentioned earlier.. it claims 250CFM, so that would work for low RPM pre turbo boosting.. but I dunno.. I always heard these things were crap..

 

[VanIsleDSM]

Just found this on another forum while searching the internet, I think it has some pretty interesting info in it that you could really use Ray, seams you should buy some adjustable cam gears.. heh.


"But this has a couple of things going for it. The supercharger pressure ratio is reasonably low at only 1.4, and if some fairly efficient intercooling is employed after the turbo, the temperature at the supercharger intake need not be very far above ambient.

The detonation problem that often plagues high boost turbo engines is usually more often due to intake charge heating by trapped exhaust residuals. The unavoidable high turbine back pressure, traps a lot of heat, especially where there is a low compression ratio.

With supercharging, or twincharging it is extremely easy to keep boost pressure well above total exhaust back pressure, and with sufficient valve overlap, the heat can escape due to much more efficient positive scavenging. With EFI, the injection point can be delayed until the exhaust valve has closed if a good fuel specific is required.

So the engine is going to have a far higher detonation threshold than can be had with a turbo.

High induction temperatures are never good, but at least with supercharging or twincharging, detonation should be far easier to avoid with some suitable (but not excessive) valve overlap."

 

[dsm-onster]

This sounds very logical. . . increasing overlap will take away some top-end, but who cares . The powerband is flat. It does this by greatly decreasing spool time. Tuning the range where boost comes on will be even more tricky (supercharger +plus rapid turbo spool).

With EFI, the injection point can be delayed until the exhaust valve has closed if a good fuel specific is required.

I wonder how this could be employed.???

. . .Where did you get this info?

 

[RayPeters]

Hey everyone,
It wasn't a planned trip in the car, but circumstances beyond my control led me to drive the twincharged car from Phoenix to Salida Colorado last weekend. I'll edit this post later today with some more juicy info, but the performance at 8000 feet is awesome. I wish I had time while I was there to meet up with a few of the high altitude guys and let them get some first hand experience with just how effective this setup is up there. 30 PSI, pump gas, no detonation, what else can I say? Full boost @ 2800 rpm. (Remember I ECU limit this due to bearing loads) I'm planning on pulling this engine later this month and moving on to building a widebody starion with a 2.4l, m90 Eaton and a T4 of some description. Shooting for 500 wHP and some monster torque for drift/rally.

More details to follow....

Well aside from a freak axle stub breakage that left the right front wheel bearing loose enough to almost fall apart and a chewed up set of brake pads, the drivetrain performed flawlessly. No engine or SC/TC problems, didn't have to re-tune (hotter spark plugs would have been nice the day it SNOWED), and the passing performance compared to most vehicles at that altitude was great.
So ~2,000 miles on it over a long weekend and my only complaint is noise. Between the big exhaust, the SC bypass, and the solid engine/subframe mounts, 12 hours in the car makes me a little edgy. SC boost was down like we'd expect, ~20% or so and right at idle it felt a little soft (manifold vacuum was ~10 inches at hot idle) but by 1500 things were back to normal. Turbo spool was just like sea level, an enginie with an effective displacement of 3.2 liters will wind up an 18G nice and quick. I ha no troble reaching max boost, and it held all the way till reline. Now if I could just figure out how to get that cool air back to phoenix......

As I mentioned above, the Talon project is approaching the end of the line, I'll be trying the adjustable cam ide on the 2.4l in the new car. The SC and intake might be available for testing if there is anyone adventerous enough out here to want to try it. Thanks for the great comments over the last few months and I look forward to future discussions of this and the larger version on the 2.4l.

Ray

 

[eclipsh]

You know, the easiest way to get this nice Colorado air is to just move up here Get out of that stinking desert and come live around creeks that actually have water in them even on days it doesn't rain.

Shame you couldn't drop by. I'd have liked to buy you a beer and ridden in your car (probably in the opposite order.) Next time though!

Glad to hear the dual charger worked so well at altitude. I'll have to look into doing the buildup once I land my real job and have more than $5 of disposable income. If you really are willing to "loan out" the parts for testing I'd be game for it. I'd like to try the setup with my 3gMAS and rerouting the BOV in like factory. If I send you an EPROM chip can you read it to get an idea where my 3gMAS/750cc injector fuel maps are now and adjust them for a dual charger setup? If you aren't sure about loaning the setup out I'll just hit a junk yard for a SC sometime in the future.

 

[DSMattitude]

Ok I have a 95 TSI awd and I'm really liking the idea of twin charging it with a small, supercharger (maybe off a GTP) Or something similar in size. Also im looking for one that would have its own oil system. I will also be running my bullseye t04b v-trim, but i want good power down low for road racing/ auto-x. Once i pick my SC and buy it, im gonna fab a intake manifold that it bolts to, and then ill get to figure out the TB n such. Any ideas? anyone seen this done before, or have an idea on what supercharger would be well suited for this?

P.S. I know this set up wont be GREAT for top end, but i got that covered(95 gsx)

 

[ilco187]

you must mean this

YouTube - Twincharged 2.3 stroker M62 Eaton and a GT35R!!!