Hi all,

I have been thinking of twin charging my 4AGZE, as it is I haven't installed the engine or the sc14 onto the motor as its in need of a full rebuild plus some! Just keeping it simple I was thinking of having the induction start coming into the sc14 pass through a wide narrow FMI into the turbo, out the turbo through another wide narrow FMI of the same spec then into the TB, running BOV etc.

My main question is what turbo would be the best for response? as I don't want lag and all the power at 6500-7000. I have looked at both the GT2554R and the GT2560R as I want ball bearing for obvious reasons.

If anyone has used these 2 turbo's let me know what they performed like if you have any vids that would be sweet! doesn't have to be in a twin charged set either

what turbo would be the best for response? as I don't want lag and all the power at 6500-7000

 

That shouldn't be a problem with a supercharger, as they do all the bottom end work don't they? The problem is they run out of puff at high revs, which is where your turbo takes over.

 

What do VW do? They have a lot of experience at twincharging.

I'm with him! Why go to the trouble of twin charging? The whole point is the supercharger to take care of the response at lower revs and then the big turbo for the outright power.

if you are serious about picking the correct turbo for your application, you need to start looking in the maths of turbo selection.

 

this is a fairly good overview.

 

http://www.enginelogics.com/cmaps.html

 

compressor maps are available for most common turbos (garrett etc) from their website.

 

the problem may come from trying to decide how much air your engine eats, there are forumlas and calculations that can be used to get a decent approximation. i have a speadsheet at home for the 4age, but not sure on its accuracy of where i even got it, i can have a look if you want though.

I don't know how feeding a turbo with charged air is goin to help let alone 2 intercoolers,

 

Feedin the supercharger with forced air that has already began feeding the engine, don't quote me, but has been done check the rides thread

Ke70dave that would be great if you could pass that on, i have been researching and trying my head at the compressor maps etc.

I do realise that the sc is for low end power and turbo up top, so I guess I need to figure out when the sc is reaching its limit so the turbo is taking over for top end power.

i have seen a setup like you describe,

 

twin intercoolers (small ones), OEM sidemounts from memory.

 

i think it went turbo-intercooler-supercharger-intercooler-engine.

 

he was claiming something like 10psi at 2000rpm and 18psi from 3000 onwards?

 

"foxtail" his name was, used to sell those razor back ecu's.

 

needs a fair bit of development to get it right though, he had pipes going everywhere as different vac references, an extra throttle from memory, one activated by vacuum to keep the idle constant.

 

i belive he did it for an academic excercise, and pulled it off quite well.

 

http://www.rollaclub.com/board/topic/25047-twin-charged-ke70/

 

unfortunately been a few yrs, so photos are gone.

digest this and you shall be almost there.

 

Edited March 7, 201214 yr by philbey

digest this and you shall be almost there.

 

 

Thank god for engineers. While I have no idea what that is trying to tell me, I'm sure that if I did it would be very handy lol. Time for me to start reading.

Just need to get your head around what the S means.

Just need to get your head around what the S means.

 

Super sexy time?

 

Seriously though, I don't know. I'm going to have myself a google search and get back to you. I really want to know now.

I have been thinking of twin charging my 4AGZE, as it is I haven't installed the engine or the sc14 onto the motor as

 

SC12 or SC14? The SC12 is the standard 4AGZE item where the SC14 is from a 1G engine & requires a few modifications (read: is a pain) to fit onto a 4A (if I recall correctly).

SC12 or SC14? The SC12 is the standard 4AGZE item where the SC14 is from a 1G engine & requires a few modifications (read: is a pain) to fit onto a 4A (if I recall correctly).

 

Is it just an issue of mounting brackets, anything to do with mounting etc? If you can remember?

From past reading of threads I'm too tired at the moment to locate (this is where I need Trev, Philbey or Hiro Protagonist to correct me if I'm wrong), none of any of the brackets will work so they will need to be custom fabricated & you also need to get the pulleys/piping to line up. All the while trying to get the blower designed for an inline 6 cylinder into an engine bay designed for an inline 4. I was doing some research a while back trying to see if it was worth it as SC12's were a little hard to find at that point, not worth it for me. :)

Edited March 7, 201214 yr by carbonboy

From past reading of threads I'm too tired at the moment to locate (this is where I need Trev, Philbey or Hiro Protagonist to correct me if I'm wrong), none of any of the brackets will work so they will need to be custom fabricated & you also need to get the pulleys/piping to line up. All the while trying to get the blower designed for an inline 6 cylinder into an engine bay designed for an inline 4. I was doing some research a while back trying to see if it was worth it as SC12's were a little hard to find at that point, not worth it for me. :)

 

Fair enough, I see where you're coming from. Just wondering if he's going to go to the effort of twin charging a 4AG, could he go through the hassle of using the SC14. If, like you said, it's even possible.