Quote:
|
Originally Posted by Eyelise
I like hearing alternative views. Thanks for your contribution. I would really need to see the torque curve to better understand your statements. I can't get past the old familiar adage "small engine + big turbo= lag". It is not enough to produce more torque than NA everywhere. I want the set-up that will give me maximum torque down low and then a nice flat curve across a broad RPM range. I'm not as interested in huge peak numbers. Don't get me wrong, I'm looking for close to 300 whp but it is the delivery that really matters to me. Show me the torque curves baby.
|
Definetly different strokes for different folks. I've got both big turbo and small turbo cars in my life. Both have merit IMHO.
On the 1Z Toyota in our MR2 Spyder kit you can really see the different characteristics of the turbos when going from the 28R (rated from Garrett at 280hp) 28RS (rated 320hp) and the GT2871R (Rated at 385hp) all on the same turbo kit and car.
The 28R has lightening response and a linear pull from 2200-2300 to redline...very supercharger like feel.
Transient response of the turbo in part throttle driving is out of this world.
The 28RS has more of a "turbo" feel on the top end, a bit less responsive to the right foot but has a lot more "go" when you do mash the pedal.
The 2871 is a wait for it...wait for it...wait for it..HOLY CRAP turbo with real soggy throttle response.
It reallly comes down to throttle reponse and transient response IMHO.
I've noticed the 1.8 Toyota's for whatever reason do not come close to motivating a turbo like a 2.0 liter Nissan, Honda or Mitsubishi. We've got a GT30R on an SR20 powered SE-R here that is simply a monster and will build 12 psi of boost by 3200rpm and is in full swing by 4000rpm - better than a GT2871 on the 1Z/2Z.
The K20 is a whole different animal. It's a very close relative to the Nissan SR20. It has a square bore and stroke (83mmx83mm) and head that flows like the dickens. (Over 300cfm stock!) It also has a pretty healthy bottom power curve end compared to the 2ZZ.
Eyelise: I think this is more the power curve you were talking about that you prefer.
That is from our Mazda 3/6 kit with the GT28R on the 2.3 liter Ford engine. WICKED responsive - Audi/VW like, but still pulls good on the top end. That's all you will get out of that turbo on that motor before it starts falling off on the top end. It's done with a capital D, BUT the car is a freakin hoot to drive.
This is a 2ZZGE with the GT2871 mentioned above at about 11.5 psi of boost.
The VE of the 1.8 Yota just isn't all that great on the small cam, and it really doesn't push a turbo that well. Not to say that 140ft lbs at 4000rpm isn't about 40 ft lbs stronger than stock but you can clearly see where the turbo comes up and the power and torque takes off. It's building boost down low, but the turbo doesn't swing into it's sweet spot till about 4700rpm.
That turbo is still streetable, but I would questions anything larger on a mid engine rwd car. Snappy power on one of these can spell trouble IMHO. It does for the MRS - ask me how I know. My rear quarter panel is primered for a reason.
Just my $0.02