What would be the concerns in twin charging a stock turbocharger LNF motor. I realize direct injection has limitations, I also understand the problems associated with tuning an twin charged engine. This would be a winter project, something I would do just to see if it can be done, and because I am a horsepower freak. Also know that the pistons will need to be upgraded to the Wiseco slugs...Any thoughts?

 

Lol I just asked this question in another thread

 

Damn, if I saw it, I woulda elaborated there. I searched, came up with a bunch of LSJ stuff.

 

I can see possible doing a remote mount large turbo in addition to the K04, but you will have some problems getting a blower on. Maybe a rotrex in addition to the Turbo might be nice, and it wont interfere with the mani.

 

It was in a thread about a twincharged LSJ. Noone is up to answer but i just posed the question of what all it might entail.

 

Well If I had to I'd build a mani for this purpose. I fabricate fixes on logging equipment all day that's far too old to have "parts" available at a dealer. The only issues I foresee is the manifold and supercharger pulley drive. Everything is already preset to manage pressure, addressing the intercooler/aftercooler setup though...

I suppose the why is simple, best of both worlds, midrange torque and an incredible throttle snap and top end. I'd not want to make more than 400HP, I would be more interested in the availability of power across a broader RPM range. I also believe that I can get lower EGTs and better road racing results. I recently started datalogging EGTs (before turbo) with my superchips tune, during roadracing, I am uncomfortable seeing 1500-1575 degrees after a couple laps and find myself getting out of the power a little bit when I notice it. I have seen 1470-1500 stock tune so I think there is room for improvement. Clearly the engine wasn't designed to produce that much power for long durations.

Personally observed my manifold dull red and smoking pulling into the pits, and I think I torched my mani gasket it's gotten raspy recently.

 

you'd need a custom fabricated intake manifold. The LSJ manifold will not clear the DI injectors. That will be the hardest step

 

I wonder if twin charging using a centrifugal supercharger would work?

 

it would in theory, you would just have to modify the intake tract, just like a TT setup.

 

I've found that the people that really make the power, and go about doing things like this, don't talk about it for months and ask opinions.

They just do it.

 

Your right if it was an F Body or something like that, well within my comfort zone, I wouldn't ask anyone about it, but this is the edge of my comfort zone with direct injection. We did a super/turbo duramax not too long ago, which was a lesson in correct supercharger trim, (remember diesels have no throttle body)

 

its the same level of custom fabrication....why is DI putting you out of your comfort zone? nothing's really different, except you wont need larger injectors now

 

The reason twincharging works for the LSJ is that you have a small supercharger for low boost, and also for spooling. So you can quickly spool a larger turbo with it and then see the big HP numbers from that. But people only do it because you already have the supercharger, so why not use it. With the LNF you'd have to buy a supercharger AND the bigger turbo, might as well just go TT.

also, i know very little about this, so i may be wrong.

 

I wouldnt go TT. But you are right, you would still need to get a bigger turbo, unless you already have one>?

a supercharger is not needed for the 1400rpms of turbo lag we get, lol.

 

I've always wondered why people dont go TT. in my mind its the same as twincharging. one for low boost, the other for high boost. Does the larger turbo actually make the smaller one take longer to spool since its not belt driven or something?

 

TT on a tiny 2.0L I4?!?! unless you have an even smaller turbo than stock do low rpm and a BIG turbo do higher rpm..that is kind of not going to work with just a small engine and room.

your reasoning for twincharging the lsj, is the same for a lnf but opposite. the lnf has the turbo just needs a SC. like stated above I dont think its been done, but a new IM would be needed. Or a centrifical SC. I would love to see someone do this.

 

yeah, like i said, i dont know too much about turbos. but with the LSJ you have a small supercharger big turbo. the stock turbo on the LNF isnt big. you'd have to go buy a bigger turbo if you wanna put down big HP numbers and then you have to go buy the supercharger. there cant be THAT much lag on the stock turbo to warrant a supercharger. especially since the higher end will be limited without going to a bigger turbo. or maybe i'm just talking out of my ass...

 

ya I agree on the stock turbo. there isnt a ton of lag and imo its too small to twin charge with a SC. If you did big ass turbo and a sc similar to what zzp does for their lsj's i could see it being worth while. but still we have the fueling issue that seems to be...sorta maybe worked out by trifecta. but not fully. zzp would probably be one of the better places to contact to see what they think about twin charging a lnf.

 

reasoning behind that is there isnt alot of room to work with in our engine bay to go TT. Plus TT isnt the norm for a 2.0L 4 banger. Can you imagine the two charge pipes coming from two turbos in the small space near the firewall behind the block and wrapping over and around the engine and joining at the intercooler? Not to mention there would have to be enough room for two intakes and the sensor is only on one intake. Two BOVs would be cool, lol.

it'd be alot of work to change the oil as well.

and yes Im talking about a turbo after a turbo. not two cylinders into two different turbos, lol. sequential twin turbo

 

No your not getting it, I'm looking to shave time in road racing by building a 365-400 hp setup that meets EGT requirements but is snappy enough not to suffer turbo lag, i.e. I can dip hard and pull hard without much if any noticeable lag. It's popular on stripped down porsches to add a belt driven supercharger sequentially to the stock turbocharger. They are completely different animals when it's been done and I'd like to see the same benefit of instantly available power. It's really important to me since FWD being what it is, I have such a small window to make use of power that I want to make use of it as quickly as possible before shutting it down in a turn.

So my only questions are as follows.

Would a LSJ (size not specifically so) supercharger feeding the motor after the turbo reduce my EGT whilst increasing power? Would a compounded turbo setup achieve my goals a little better.

Maybe someone from ZZP can speak up on the matter, this isn't a car to be used for drag racing, I RARELY go to the dragstrip. I am a road racer/auto x, I like the technical challenge of getting a car through a series of turns as quickly as possible.

So again, goals: 365-400 hp on tap, reduce the current turbo lag and reduce the EGTs as measured a few inches before the turbo. I am already upgrading my brakes and suspension to match, I've also already removed about 85 lbs of weight. Theres just not alot of answers to be had from anyoen I know or anythign I've read about this particular setup for this particular purpose.

 

Twin turbos on a 4 cyl reminds me of the EIGHT TURBO'd V8 that was circulating on you tube a while ago.