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Old 04-05-2007, 01:48 PM   #7
pwpanas
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Quote:
Originally Posted by chuan01
...also, i'm lookin at spending maybe $20k on mods after i've bought the car. any tips on what mods would optimize my car's performance and handling? (i dont want the car to be any more powerful than 500HP)...
Performance:
  1. Do you mean 500hp or 500rwhp?
  2. If you're talking about 500hp at the crank, then you won't need $20k in mods...you'll just need a full set of 'bpu' modifications, a front mount intercooler, a fuel controller, cam gears, and some race fuel.
  3. If you're talking about 500rwhp reliably, then you'll need a single turbo system. If you want to run it on pump gas, I'd recommend a meth+water injection system as well. For 500rwhp you'll also need a new clutch (or transmission upgrades if it's an auto).
Handling:
Actually, the oem coilovers are excellent. The oem suspension actually roadraces just fine, and has done VERY well in circuits such as OLOA. 'Keepin' it real' here, most guys put coilovers or springs on their Supras because they think it looks 'cool' to have the car lowered. If you want to look cool, then that's fine. If you want the car to perform, the un-lowered mkiv tt oem suspension can outperform a lowered mkiv tt in many roadrace driving conditions. Of course, the oem suspension will handle most street driving situations (eg potholes & speed bumps) much better too.

If, after aggressively roadracing your Mkiv Supra TT on a real roadrace track, you find the suspension a bit mushy, all you need to do is replace the shocks (not the springs) with a set of KYB/AGXs. Again, I'd recommend you drive the oem suspension first, before you decide to make that change, because (again) the oem jza80 tt suspension is actually a great setup.

If you are extremely serious about competing at roadracing, then of course a full set of integrated, adjustable coilovers and sway bars can be beneficial. Also note that this type of extreme suspension upgrade can make your Supra MUCH less friendly for street driving. In short, if you want your girlfriend's fillings to fall out of her teeth on the way to the movie theater, then go ahead and install a full set of race coilovers the same day you purchase your Supra.

General Tip:
Lastly, be sure to set aside a good chunk of that $20K you mentioned for upgrades...in order to do full, proper maintenance on the car. Who knows what might be wrong with it if you purchase it used, especially if it has higher mileage. It might need a full 60K maintenance, including a new timing belt. It might need new coilpacks or a new harmonic dampener. Hell, a full set of good z-rated tires can run over $1K usd. This car is much more like a Porsche/Z06/Ferrari/Viper to maintain properly (i.e. don't budget your maintenance $ for the car like it's a Camry/Corolla/Celica/etc.)
Quote:
Originally Posted by chuan01
...one question though, the stock turbos can handle the 500hp right?
500hp yes, but not 500rwhp.

Quote:
Originally Posted by chuan01
...roughly how much more does it cost to do the modifications to a non-turbo? because i find that the cost of a non-turbo 2JZ is a lot cheaper than the turboed 2JZ...
There are many, many, many differences between the turbo and non-turbo Mkiv Supra. Not only is the engine completely different (head is completely different, and so is the ignition system, the intake & throttle body, injectors, ecu, compression ratio, pistons, oil squirters in the block, etc., etc.)...so is the entire braking system/abs, ecu, transmission, suspension (shocks, springs, sway bars), differential, etc. etc. Most people I know that have done a detailed cost comparison have concluded that it's MUCH cheaper to purchase a TT Mkiv to begin with, rather than start with a normally-aspirated (non-turbo, a.k.a. "N/A") and then do the conversion. In other words, if all you do is add a turbo, you'll end up a lot of horsepower but an overall vehicle with no driveline components or brakes to handle that increased horsepower level.

Quote:
Originally Posted by chuan01
...what's required to put turbos on a non-turbo? new pipes?...
Rofl. You'd need a >>>complete<<< N/A-T conversion kit, like this one:
http://www.boostlogic.com/parts/supr...oKitStage2.htm

Quote:
Originally Posted by chuan01
...and IF i have made the modifications, will the 5-speed gearbox make much difference compared to the RZ's 6-speed?...
Generally yes. The 6spd is a much stronger gearbox...at least 50% tougher than the 5spd. The unmodified oem 6spd has held over 1400rwhp on the dyno, and has been drag raced into the 8s in the 1/4!!! ...compare this with an estimated 575rwhp or so as the generally accepted estimated reliable hp max for the 5spd.

Quote:
Originally Posted by chuan01
...and another thing, i want to put a decent sound system in the car, but having looked at the boot space, i'm not exactly sure how i can fit a sub and amp in. any ideas?...
If you permanently remove the spare tire, fitting a nice sub & amp is no problem at all. Alternatively, one company I know of sells a drop-in sub box replacement:
http://www.wickedcas.com/gallery/mai...gicboxes/mkiv/
__________________
Phil '94 Supra Turbo, 6spd, 'APU'+
Displacement is no replacement for boost.
Life begins at 30psi.


NB: Please consider posting any help requests in a new thread instead of asking me for help privately. About 99.9+% of the time, private help requests end up covering great information that could be very valuable to other forum members. If you have a good reason for needing the help request to be private, I'll consider it. If not, then why not give everyone else the opportunity to pitch in too, and/or learn from the information? Remember, there's no such thing as a dumb question. We're all here to help within this family of Supra owners.

Last edited by pwpanas; 04-05-2007 at 03:01 PM.
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