I read your posts on the rlforums, and it seems like you and I are thinking the same thing, but maybe not getting the words right. You don't want max boost of the blower on top of max boost of the turbo. That would melt something important or just blow something up. Ideally the s/c will provide some low boost, and as the turbo starts to spool there will be some overlap, and probably around 3000-3500 rpm the s/c will be disengaged and boost will come only from the turbo from that point on, thereby eliminating both the parasitic drag from the s/c, as well as the wasted boost from spinning it so fast. (unless you got the bypass mod of course)

Here is a twin-charged car. This about what you mean, yes?

 

there is no way that you can dream of twincharging our cars for 1k! a good turbo not even the best one for our car will run you about 600, thats just the turbo. you need custom piping(about 500+), and new intercooler(300+), a exhaust manifold(500-1000), a wastegate(200-600), a bov(200-400), engine management of some sort(1000+), and a few other things. then you also have to figure out how much it will cost to put it on. another things that you guys are not talking about is the internals. im going to let you guys know right now, the internals of our cars are crap. im having to rebuild my car right now and it only has 11k miles on it, so watch out. so, building the motor(500-2000 depending on what you want). i have a turbo car and i know what it takes. so with all that said you cant even get a honda turbo kit for 1k.

 

I'm with this guy ^^^^

I too have a built up car, and it's done right, there is 35K in my motor and blower alone right now. DO NOT BUY A CHEAP TURBO that is a bad bad plan man. You might be well enough of running just the turbo. it's also really not your psi so much as the amount of air you are moving, IF YOU MOVE MORE AIR WITH THE TURBO THAN THE BLOWER CAN MOVE that extra is a waste. However have at it I think this is a very god project, but please do budget a bit more than 1K, you don't want to be half way done and out of money...

 

our bypass valve is tiny (34mm or somethign like that)...and that method could work...and itd be way too complex to make 2 inlets...the setup i described works on a redline and made 340whp. and no u dont want max turbo boost. Boost defines the pressure a volume of air at a certain temp over atmosppheric pressure exerts.

first off well just say ambient preasure is 15psi (rather then 14.7) so a 6psi charger will take in air at 15psi, and expell it at 21psi right? ok, thats simple enough... but what if there are 2 blowers blowing through one another both pushing 6 psi... you dont just get +12psi nor do you get 36psi (6x6 derf), these things work on ratios over ambient, not just static boost, so one blower pushing 6psi is putting out 21 total, so thats 21/15 or 1.4:1... so you run that through the next blower running 1.4:1 and youll end up with 29.4psi total, or 14.4psi of boost...

so ill be running a pulley that makes 12lb of boost w/o a turbo (stock) this lends to a 1.816:1 ratio. so i run 21.7absolute (7 psi boost) thru it and bam 39.4 abs psi or about 24 psi.

The important thing is to make sure the turbo is big enough to flow enough lb/hr of air...that is why i wanted a bigger one.

U would have to see which provided more benefit having the turbo run to 24 psi and cramming it thru the tiny bypass or having the turbo barely work along with the s/c barely work...im pretty sure the second way would work best

the reason is that ud have a much better chance of being in the turbos highest efficiency range with the second setup

Dan

 

a 70 is WAY too big for a twin charge as previously stated, and i hope you arent seriously thinking about 20+ psi from the turbo because you will then be running close to 30 if not more total and there is no way in hell your stock internals will hold up very long at 30psi.

 

This my sound a little odd...why not try using something a little smaller like a 16G or even a 14B....

 

The only issue I see there is that you're still having to spin the s/c. I'm assuming that while the boost is bypassed, the you're still going to lose some on the top end from spinning the blower. Would there be any benefit to a larger pulley (less early boost, but also less parasitic drag) or perhaps a higher-boosting turbo at a lower redline? Not sure if either will work, really, as I'm still reading up on this stuff, but I do know that if you're still spinning the s/c at redline, you're not getting all the potential power you could be.

 

ya its all about maximizing the efficiencies of what ur using...im either gonna crank out the calculations or trial and error it.

the manifold is 200 for me
figure 400 for turbo
200 for plumbing

i have hptuners, 60lb injectors, cm fx400, and a wideband already

i may need bigger injectors besides i wouldnt try past 350whp without new internals

 

At that level you are going to have to replace your head gasket and head bolts with stronger ones. At least Twincharged did.

 

well i hope you change your mind pretty soon about the $1K cause that aint gonna happen. the turbo kit i have on my jetta right now was around 4K... so um yeah.

i'm still learning abou the twin charging deal but when i look at VW's design they have a bypass for the SC including a SC pulley Centrifugal/electronic clutch or something. from what i see you're writing you want to just run straight off your turbo through an intercooler (yes you need an intercooler) then through the SC... at least i think that's what you're thinking. I'm courious to see if this will work. i'll have to do soe more research about the SC.... all in all give it a shot but i hope you've got some money in case it go boom boom.

i was just going to use my super60 on mine it spooled at 3G's on my vr6

 

He does not need a seperate intercooler. The stock aftercooler works very well, even on the twincharged Red Line. I belive he is seeing 130 IAT2s after converting it to a two pass system.


I say go for it Dan don't listen to the haters. The twincharging works great on Twincharged's Red Line. He got 335whp with a less than optimal tune.

 

i know most expensive item i need is a turbo and manifold...i have the rest i also have 2 heat exchanger on my system and am converting to a 2 pass. I want a cheapie ebay turbo but am afraid of the quality.

u think...did u not read the parts list...i really only need 3 parts and some clamps and some exhaust work.

an vw stuff is horrible overpriced

 

You must not know DJT. He has the fuel system upgrade and the tuner already.

If I were you I would just get a nitrous kit like me

 

You know what I must have no idea what im doing...my car traps 109 on hopes and dreams...not 94 octane and my own custom tune...with 700 in parts

 

Well that's a given. Luck has gotten you far grasshopper. Lol.

 

deet dee dee

 

so all you need to twin charge a ecotec is a turbo, manifold, and some custom piping (which is more than likely fence post if it only cost $200).... um yeah let me know how that goes chief. I'm pretty sure i know a little bit about turboing a car and a little bit about project cars they always cost more than you think they are. but hey maybe just this once i'll be wrong.

 

That's not all that is needed but he already has some of the parts. Like 60 lbhr fuel injectors, complete control of the ecu, and an aftercooler that is more than capable of handling the heat. You are right though, like most things it will probably run more than the original estimate. But no where near the $4,000 you have spent on the VW.

 

Read some of the other posts, he's got the other stuff he needs, tuning, fuel system upgrade, etc. Dan can do it and lets be honest he's going to try it regardless. I hope it works. Then you can help me with my turbo only setup Dan.

 

damn fenceposts have really come up in price since i last priced them then

and since when did buying a 4k prebuilt turbo kit make u a god of piecing together ur own and tuning it. my 1k is hopeful and completely doable with the help of friends...1500 if I go a lil overboard on the exhaust...see u only need less than 4 feet to connect the turbo outlet to the s/c and another 4 ft or less to make an intake with maf holder for the turbo the a custom piece to connect the turbo to a piece of the existing dp...but if i was in there id have all 3" exhaust made

point is pricing from ebay i can have the turbo (225), manifold (180), and oil feed/drain lines (100) for 500 the rest can be spent on pipng

http://www.roadraceengineering.com/mandrelbends.htm

But i still may not do this since i really need traction first and if i get my mid 12 goals without twincharging ill just leave it

 

Why do I have a feeling that if you get your mid 12s without twincharging, then your new goals will be high 11s, which will put you in this boat all over again?

 

i trap 109 as my car sits right now...and I just got a cobra heat exchanger and traction bar in today

 

A quick question, in a twincharger setup, what do you do with the MAF? Where do your place it? Do you use the stock one? Won't the PCM freak out seeing all that air rushing in?

I was with you until I read that last post and now am confused about the MAF

 

You can adjust the acceptable range for the MAF Frequency with HP Tuners so I don't think the extra air will be an issue. As for placement, I have no idea where it should go.

 

I will have to disagree with the first statement and agree with the second one, if for no other reason than, once a high powered twincharged Cobalt is running around djt81185 will have an amazing itch to scratch.