Originally posted by robr:
fair enough, im not sure what i can dig up but again i recall the same sort of innuendo and hinting we get from woodwork making the rounds where toyota cant come out and officially say it, but i have no reason to doubt it. the mods i posted aren't exactly rocket science and probably much of why they didn't do it had to do with emissions and someone being conservative. the fuel delivery system was clearly over engineered, if all toyota wanted was 320hp, they could have chopped a few hundred bucks off of parts by going with cheaper components here. to take a 320 hp car and drop in a fuel delivery system that can handle up to 475hp couldn't have been an engineering accident. i'll see if i can dig up some of this info as well, but it's probably not enough to factually prove anything directly.
It seems to me that the reason that the Toyota Supra and MR2 are so easy to get extra power out of is two-fold.
Reason number one is that in Japan there exists a gentleman's agreement between the major manufacturers that all domestic brand cars to be sold in the home market be limited to 280ps (283.92 hp). I think this is the "innuendo" that you are recalling. In Japan's home market, the Supra was limited to 280 ps, whereas the export model was always intended to produce 320 ps.
Many cars in Japan are released in either se-tuned form, or with bogus power claims from the manufacturer that dramatically under represent the amount of power the car is making.
Reason number two for why it is so easy to get an extra 200-300 horsepower out of an MKIV Supra (or 100-200 more out of an MKII MR2 for that matter) is simple: in the Toyota tradition, these are over engineered cars and, turbo ones at that.
While I can't speak in too much detail with respect to the specifics on the Supra, I know in the MR2 community we have similar Home Depot DIY $5 ball and spring boost controllers and $0.97 fuel cut defensers that will allow for significant power increases well above the 200 hp that these cars were released with in the U.S. As a matter of fact, in Japan, turbo MR2s were released with 225 hp, and later, 245 hp from the factory indicating that Toyota knew the 3SGTE motor to be capable of more than the stock power levels it was released with here in the U.S. Of course, in Japan the cars were released without EGR systems, restrictive secondary catalytic converters, and were run on the equivalent of 94-95 U.S. octane fuel, so a bit more power was available without putting too much of a strain on the motor.
That said, we have seen MR2s make 100 to 200 more horsepower at the rear wheels with simple bolt-on upgrades and Supras make 200-300 more horsepower at the rear wheels doing the same.
So why shouldn't everyone here in the U.S. just crank up the boost to these power levels? Simple: octane limitations and cooling. Even by removing the restrictive emissions devices, as the boost level is turned up, the car's cooling requirements and need for propensity to detonate on low octane fuel also go way up.
Here is a neat article that I ran across on the importance of upgrading the intercooler on Supras (scroll down for the section on "Intercooler Efficiency"):
http://www.mkiv.co.nz/techo.htm
While a $5-6 in parts allows the boost to be turned up on either the Supra or MR2 motor, even with stock turbos and internals, unless the owner is willing to put another $1,000+ into an upgraded intercooler to cool the intake charge, as well as $500-$2,000 for either a remapped factory ECU or stand-alone ECU with adjustments made for the ignition and fuel maps for U.S. pump gas (a $500-1,000 water injection system also helps tremendously here as well) these cars really
shouldn't be taken up to the power levels that their owners here in the U.S. regularly take them.
Yet, human nature being what it is, most new MR2 and Supra owners are quick to learn of the neat and cheap ways to crank up the boost long before they have investigated the precautions that need to be taken before doing so.
With an upgraded cooling system (and I'm talking about intercooler, coolant and oil cooling each being addressed) and a some dyno time spent remapping fuel and ignition timing curves, stock Toyota turbo motors are engineered to
reliably make incredible amounts of power. Otherwise, they will just make big power for a short while until something breaks.
FWIW, I drive an MR2 with JDM motor that makes 292 rwhp with stock internals on 91 octane pump gas. Of course, it cost me a lot more than $5 in parts to get it there. It also took 100 dyno runs to get everything dialed in properly. There are other MR2 owners making 400+ horsepower on their cars with minimal investment, but the trick will be in seeing whose motor stays intact over the long run.
As much as I like the NSX, if NW93TT really wants a reliable mid-engined two seater that feels like an elemental sports car (the sound of the motor just inches from the driver's head, the nimble precision that only a lightweight mid-engined car can offer)
and is also looking for power potential, it is still much easier (and less expensive) to squeeze big power out of Toyota factory turbo motor than adding forced induction to an NSX.
-- DavidV
www.boostedgroup.com
[This message has been edited by BoostedMR2 (edited 30 July 2002).]
, but they are not in the same catagory as the mustang/camaro crowd, that same crowd is calling all of the cars above overpriced riceboy cars. ken, its no secret you think the supra is a fat pig, i for one think you're an idiot for that opinion, but thats just me
