hp gain on bpu's

[liazon]

if you know your stuff, please take the time for the new generation of supra enthusiasts by helping me (as one of them) out by verifying my research (below) and answering some questions. if your new, like me, this thread may prove most beneficial by educating you.

i have just bought a bone stock 94 tt. i wish to upgrade it as smartly and efficiently as possible. i am not loaded.

1.Downpipe: offers 30-60 hp increase based upon the air moving more thoroughly

2. Exhaust System: a 2psi gain in the turbo (sorry, i'm confused, but is the downpipe a separate thing from the exhaust system? is the exhaust system basically a muffler? is the hp gain listed in #1 separate from any hp gained for #2 or does it include it?)

3. BCC: this eliminates the engines computer shut off limit of 14psi of turbo boost, which one can expect to achieve w/ the addition of #4. (supposedly, the 94 and 95 don’t have the computer shut off and therefore don't need this device, is this true?)

4. Electronic Boost Controller: (apx $325+labor) uses vacuum pressure to hold open the turbo longer for higher boost; stock is around 11psi, w/ this upgrade expect 15-17 psi which is equal to a 60-70 hp gain (this is my #1 priority, how much should i pay for installation of this device and what accessories to it are required other than #5?)

5. 52mm Greddy Boost Gauge: (apx $150+labor) critical to show the upgraded turbo psi, as one should never run more than 18psi (w/o major mods). (how much should i pay for installation of this device?)

6. Performance Springs: (apx $280+labor) make the car more stable in cornering situations and cosmetically make the car more appealing by lowering the car 1-2", especially important when upgrading to bigger wheels. (how much is installation on these and is there a downside? would i notice a difference if i don't upgrade the 17" wheels)

7. Air intake system: (apx $250+labor) super ez to install this device which raises the amount of air sucked into the engine, more air=better performance. (how much horsepower will this add? is the filtering rating mor important than the performance rating? ie, apex and k&n have best ratings for air filtration)

2. Blow off valve (apx $300+labor) protects the engine when backing off the throttle when pushing very high psi boost. (do i need one of these if i'm limiting my psi to 17 and below?)

Your comments and expertise are greatly appreciated. Cya out there!

[DakaDan]

www.mkiv.com will have all the answers u need under the FAQ... Better then me writing it all out. If u need more help, post questions!!



DakaDan
12.2 @ 118

[liazon]

thks for the reply, unfortunately, 'fax' on mkiv hasn't worked (for me at least) since they uptdated the site a few months back.....if you get it to work, plz. copy and paste it too an email to me: [email protected], although i have to admit i'm skeptical as this was one of the majore sources of my research thus far.

[Fried Rice]

Im hoping to pick up a supra relatively soon.
I drive a corolla now, cuz Im 17 and I am a flat broke bastard.

First thing I would do if I had one... take that godforsaken spoiler off.

[badger]

Liazon,

Congrats & welcome to the MKIV Supra family!
Quick answers are:

1. Yes, roughly 30-50ish hp increase due to downpipe (aka DP). Increase is due to reduction in backpressure to the turbos by elimination of the two catalytic convertors. This results in the turbos being able to build more boost.

2. Exhaust - also known as a cat back exhaust. This is separate from (and after) the down pipe. Cat back refers to the exhaust system from the catalytic convertors on back. Performance increase is again due to reduction in turbo back pressure and corresponding ability to build more boost. Hp increases from DP and exhaust are separate and additive. In other words, you get both - to the extent that they both will allow an increase in boost.

3. Boost Cut Controller - this eliminates fuel cut off which would otherwise occur if boost exceeds stock levels. A FCD (fuel Cut Defensor) or BCC (and the BCC is recommended over the FCD), is needed to increase boost levels above stock. On a Supra TT, this can be done by simply pulling a few hoses and costs virtually nothing. A BCC is not mandated by installation of an electronic boost controller. A BCC is mandated by wanting to exceed stock boost levels - which can be accomplished by various means. If you put on a DP and cat back exhaust, you'll likely hit fuel cut on hard runs in the cold weather.

4. An EBC is NOT a priority. Priorities should be: Turbo timer, boost gauge, intake or drop in filter, DP, Cat Back exhaust, then boost controller - either manual or electric. Oh yea, then you'll also need new tires - especially the rears! The above mods will run under $2K and are known as BPU - Basic Performance Upgrades in Supra parlance. BPU level performance is 400rwhp. All of the above mods are easy do it yourselfers - especially with mkiv.com as a guide. You can learn A LOT from mkiv.com, although I appreciate your comment about the FAQ section being down - great info there.

5. Yes, you need a boost gauge. Suggest you get an electric one with peak hold function. 18 psi is a typical max boost level for BPU mods. Boost gauge is another easy DIY - many put in the clock position. I put it in the A pillar mount along with an EGT gauge.

6. Don't know about lowering springs - cosmetic as far as I'm concerned.

7. Air intake - careful here. Depending on how you do this, you may not see much if any performance gain if you end up sucking hot air. A K&N drop in filter in the existing air box is the cheapest and easiest way to reduce inlet pressure loss on thhe turbos and increase performance.

8. After market Blow off valves - not needed, no real performance benefit, but sound really cool.

Email me at [email protected] if you have any further questions. I check it almost every day. I've owned a 97TT for just over a year now and have taken it from bone stock to a little past BPU in that time. Have learned a lot - mostly from MKIV.com and supraforums, but still have a lot to learn.

Jim
97TT BPU
12.6 @ 113

[liazon]

thanks for the great information!