I've been interested in the various powerbands that are possible. I'm asking more about an experimental idea than a real build that I'm doing. It just has caught my curiosity and I'm wondering if it would work....

What if you built the motor as if you were going to make 600-700whp.... full 2.4 stroker build but stick with a smallish turbocharger like the Green or Map EF2.5. Try to spool it up as quickly as possible and peak the torque quickly without caring about how much it pulls afterwards. Run a little more psi than is usual with those smaller turbochargers and simply do everything to cool it down.... Dual intercoolers, two oil coolers, pure 100% water coolant, aquamist, and stockish cams.

Shoot for 500-600wtq right around 3000rpm and be lucky if it makes 350-400whp since it will surely be choking up top. Optimize everything for spool at the cost of RPM and high end power. Redline at 5000-6000rpm.

Maybe even run a smaller snail than the Green and just spool the hell out of it and get hot air. Short shift early and avoid high speed runs that would get too hot. Again with all the extra cooling and a built motor will that work? Assuming the drivetrain can handle the torque (call up jack's) it seems interesting. Obviously this is not building for longevity but rather low end fun. Normally the fast spooling turbos don't have a built motor. Built motors generally get slow spooling turbos. What if we did the opposite?

Before people say I'm crazy understand I'm not really planning this. I'm just curious if it's possible....

 

use a turbo restrictor plate small enough and you will instantly have more TQ then Power.
But you will not be happy a driving characteristic with a restricted car.

usually rally cars have around 300-320 whp and 480 wtq and above with a 2l engine.

Now with the 2.2, i can only guess you can get into the 500-500 wtq range.

 

You are still going to have a low compression, small 4 cyl power plant pulling 3,600 pounds of car from idle to 3,000 rpm until you start spooling the turbo. I think maybe you need to consider a smaller turbo than stock, something that can spool sooner. Does the RA have the same turbo as the Evo?

 

Dual-charging (i.e., a turbo and a super-charger)?

 

Find a v8

 

like this ?

 

That looks like an intense workout, that's one hell of a driver.

 

Yep. That was pretty much exactly what I was thinking. And, of course, because it worked so well, it was banned, along with all the other Group B cars.

 

RobevoRS: The restrictor is a large part of what helps rally cars make so much torque, but I also thought it was mostly attributed to their Anti-lag systems which spool up a larger than usual turbocharger low in the RPM band.

If the restrictor really helps that much, why don't turbo cars just artificially restrict the charge until higher RPM where it's opened up..... Similar to intake manifold runners which cross-over to highrpm? Wouldn't that provide capability for much more torque without choking the top end? It just doesn't seem that easy, there has to be more to the equation....

Regarding the buy a V8 comment, I still don't see those making 400wtq before 3000rpm unless turbocharged. As I said before I'm not really "serious" just curious. V8's are off topic.

After seeing what people have done on the stock turbo I'm thinking this goal can't be too far off.... Full-bolt on Stock-turbo Evo 9's have made 400wtq by 3000rpm which is incredible.... Considering Evo X has better spool potential, you'd think a built motor could spool a slightly larger turbo about as fast to make more than 400wtq.... The way I see it spool is really what matters. It's just that the stock motor will puke it's guts out if you spool it up any faster.... built motor won't, yet no one seems to attempt to quick-spool one.

Again I'm just curious and looking to chat about this type of build. I'm not trying to do this on my car. I like the theory behind it.

 

sub'd

 

I saw a video online a few years ago where a guy threw on the supercharger from a mercedes and had it working on a 4g63T. But he didn't have dyno numbers.

Somehow I just don't see this option helping. Here's why.... Unless you run a super small pulley the supercharger won't really be boosting much down low. If you run a small enough pulley to equal real boost before 3000rpm, it would be so small you'd overboost/overspin the blower above that rpm. The only thing I can see working is to run a pulley that makes more power than needed, and use an external wastegate to bleed off the extra boost outside the low-range. (Assuming the blower lasts)

But that would slow down the initial spool (I believe) and further heat-soak the charge. Spool is what matters otherwise a 700whp 6000rpm-spooling 45R would work..... Running a smaller pulley also means it will run extra hot and restrict power due to lower timing before knock onset.

I think the key is simply to spool up the turbo faster. Then do as much as possible to avoid the heat problems from running the turbocharger outside it's efficiency range.

Keep up the interesting discussion

 

I do not know why it works, but I've seen enough reports to be somewhat convinced that dual-charging IS a good way to have both low torque and a top end. That Lancia had something like 500 foot-pounds down low and, after dumping the restrictions of FIA, around 800 up top. All from 2 litres. What more do you want?

 

If you could somehow run a small pulley on a clutch system similar to a a/c compressor that could work till the turbo can take over making the boost. Then you wouldn't have to worry about it over spinning. Possible?

 

You guys need to look more at engine design--as for super charger vs turbo--super chargers are parasitic and therefore not the rt choice. To build torque by design you need : Square or over square- stroker motors, small diameter ports on the head, long runner intake manifolds, small diameter exhaust runners and 4x2x1 header designs---, smaller turbos with limited functional range. these all build midrange and lowend. Restricted intakes etc are only a small part. if you could make it a flat 4 (ie sti or old VW) then you get even more added benefit. Build something with the above specs and you will have a torque monster--

 

You do realize that Rob and I are talking about having both, not one or the other, yes?