ShapeGSX

Where would you put the supercharger? The back seat?

Centrifugal superchargers actually reach full boost at a much later RPM than a turbocharger since their drive is connected to the crank. As well, they put a huge strain on the main bearings and the crank itself.

Roots superchargers can't really be intercooled easily, and have horrible efficiency, but they do give decent low end torque. But you would have to bypass it in the upper RPMs, which is also not easy. And after that, you would still have the drag on the crank.

If you want low end torque, use a smaller turbo.

Pesto360

iTrader: (2)

maybe two turbos?

ShapeGSX

Two smaller turbos that divide the exhaust from the 4 cylinders equally will not spool up any faster than a single large turbo.

You would need a system with 2 different sized turbos, and a system to divert exhaust to one or the other. FD RX7s used to do this. But it took a lot of custom cast exhaust parts.

I just don't think any of this stuff is worth it.

Is the lag really all that bad? What have you done to optimize the exhaust, intake, pipes, etc...

Personally, I think that the Evo's 16G is the ultimate street turbo for a 4G63.

Pesto360

iTrader: (2)

the lag isnt bad..would just be nice to have more useable power down low..its actually pretty scarey...its the same dyno grapho almost identically to my 3037s kit but with 3pounds less boost and same hp...

chronohunter

iTrader: (1)

Shape, you failed to mention the Whipple Supercharger which nearly as efficeint as a turbo. It needs a high boost/ no boost bypass and a computer controlled clutch to turn in on and off. plumb it before the turbo compressor so it spools the turbo from the COLD SIDE then it gets bypassed as the turbo takes over.

The eletcric suprercharger option would be interesting if used for anti-lag. It runs on capacitors and can provide (they claim) 15psi. That'is more than enough to spin up your turbo it needs to be controled by throttle position (on) and boost (off) just like the progressive nitrous system (which is still the cheapest solution )

Why not Shape...Think outside the box! BTW it has all been done before...Lancia Delta S4 group B rally car

meanmud

iTrader: (74)

Wasn't there other cars too?

Also - I PM'd you - advice appreciated

vr430

iTrader: (2)

Yep. As I remember - please correct me if I am wrong, - early Killer B 205T16's came with two turbochargers - one small, one big. Sure helped them win tons of rally races, including Paris-Dakar.

ShapeGSX

I know it has been done before. But have you seen how complex a Lancia Delta is? Holy crap! They needed half the car to plumb all of those intake and exhaust pipes.

vr430

iTrader: (2)

Yep, plumber's paradise, looked really cool on my scale models

MrBonus

iTrader: (4)

You wouldn't happen to be biased, would you?

ShapeGSX

I'm being quite honest. The Evo's 16G doesn't have much lag, so it is pretty torquey down low. Yet it can still flow a ton of air up top. Even on pump gas, there aren't many cars on the road that can beat it, once set up right.

Then throw in some race gas at the track, and it gets even better.

I bet someone will run better than 120mph in the 1/4 with the stock 16G this year. Hell, I'm aiming for that with my own Evo III 16G on my Eclipse.

MrBonus

iTrader: (4)

I agree completely. After adding the turboback and Profec B, my car feels much stronger at 2400 RPMs than my Cobra did. Add in the AWD and it tears right off the line.

I don't doubt 120 MPH is achievable, especially with this blistering cold weather on the Mid-Atlantic.

I like the larger turbos but from stoplight to stoplight they don't have the response that the stocker has. Good luck when the tracks open up.

slowTsi

I beg to differ on the evo 16g being the best street turbo. A well designed t3/t4 50 trim kit will spool up in the 3500-3800 rpm range. That's only a little bit later for a **** load more air. Sure, the evo runs dsmn nice on your set up but I don't think there is too much left in it power wise and I dopubt it can even sustain those high boost levels with race gas by redline. I'm not knocking your car or your set up but it's going to be hard to get 6 or 7 more mph out of it. There's def. not much left in that 60"!! Damn that's some good driving.

Pesto: There are three good solutions for you:
1. Be a man and take the resonators out. If's it's too loud for you then just get a bigger or less aggresive muffler.
2. Switch to a smaller a/r. This is going to cost you some up top but you can up the boost to get the power back.
3. Build a stroker or a straight 4g64. A 20% increase in displacement will really drop down those spool up times as well as give you more power off boost.

Or you can just live with it and learn to brake boost.

ShapeGSX

I'm 3/4 of a step ahead of you. I already ran 118.02mph with my Evo III 16G this past October. I have datalogged the turbo at 25 to 26psi, and it is pushing a whopping 44.1lbs/min of airflow.

The timeslip in my signature was run at 22psi, and 40lb/min of airflow.

Figure that you get about 10hp for every lb/min of airflow. Can a 50 trim flow more? Sure, but not a whole lot more, and not with this spool-up.

slowTsi

That's a nice step up but your still going to need a couple more lbs of air to reach your goal. It's going to take 45-47lbs/min to hit 120. I'm sure you know that the 50 trim will flow that kind of number on pump. I've heards this from several people on the dsmlink forums. I hope you reach you goal! I'm going to hit 120 on the 50 trim, but that's a few mods away yet. gl