would appreciate some well known guidance to help upgrade my bone stock '97 MKIV auto

[jzzrs180]

Ok cool So talking stock MKIV TT here for a sec, I mentioned air:fuel ratio because for example, if a sports car uses increased air (the twins) to increase the cylinder pressure, you would need a high octane gas like 93 to be able to ignite it at the right time, and burn that off efficiently. But I guess what you are saying is, (if I have you right), that if I were to manage a good bpu I wouldn't have to worry about air:fule ratio because your the ecu reads your increased air automatically and auto corrects your fuel consumption? (Please bare with me LOL) So then, can you explain how and where do I get this mixture of higher octane fuel, and is it stored in the main fuel cell together? What is that ratio lol? sounds like a pain in the ass to fill up..ha. I always thought 93 was good enough..(BTW I collected all my questions for ya at the bottom)



Do you mind diving into the adjustable cam gear thing a little more for me if you don't mid. My understanding was controlling the cam gears with opening n closing of the valves in relation to TDC is basically how to improve hp, but why? Because you're allowing more fuel and air in longer before TDC? If so why is the exhaust gear more important to adjust, and what are the popular degree(s) for a bpu, with say.. 15psi?

As for the Paxton system, saw it on this guys youtube upgrade vid I believe and again somewhere else..BUT, I will take your word for it!! LOL, what are your top 3 favorite systems or the 3 most popular?

And to clarify the thermometer thing, sorry I was saying I thought if you increase your hp past say 500hp that you would have to upgrade your cooling system, which includes radiator, water pump, piping, probably your fmic, and the thermometer, along with the fuel system, fuel lines, pump, filter, injectors..Since the stock system has trouble keeping up with the added power. Am I correct?

Yes it's intelligence (ECTi), that I knew, and my guess is that it just means better response with your throttle at low and high rpms.. I just wanted a more clear understanding if you could clarify better.

Again:
2) What kind of fuel do you plan to run? If you limit yourself to 93 octane ((R+M)/2), then you'll be limiting yourself to about 15psi of boost with the oem twins and the oem ecu.

Well since today I was not aware that 500hp, 600hp, etc. upgrades required higher than 93 octane fuel..naive me!! This is what I pulled off of Wikipedia--"Racing fuels, avgas, liquefied petroleum gas (LPG), and alcohol fuels such as methanol, may have octane ratings of 110 or significantly higher. Typical "octane booster" gasoline additives include MTBE, ETBE, isooctane and toluene". So again how, and where, and at what ratio do I make this fuel work for me?


8) What is your horsepower goal? 800rwhp? If so, that ain't happenin' on pump gas lol.

I saw somewhere that a guy was running high horsepower on a flex fuel mix, know anything about that? He had a youtube vid and all, him at the gas pump filling up 85 with a gauge, and then filling the rest with another fuel..And yes I eventually wanted to reach the 7's or 8's in hp, or until I'm satisfied with where I'm at. Listening and learning from pros like you will help me get a better understanding of my goals. I must say though, it is a craft I want to someday master!

9) Do you intend to stay with the oem twins or go to a single turbo? About 450rwhp is max (6spd) with the stock twins, so I guess they're out. Right?

For a bpu, idk... i guess see as I go? Eventually I'd like to hit those higher horse numbers like I already mentioned, but do I have to then switch to a single? I have seen most nutty 1000hp Sup's (or some with a little less) possess single turbos, but also heard/seen a few that maintained upgraded twins as well, is that unnecessary because of cost to stay with twins? One of my ultimate goals is a strong, quickly responsive powerband all the way through with as little lag as possible starting at low rpm, yet still able to drive it like a regular stock toyota Somehow that still screams twins to me..! And I heard you can achieve these goals in the 700's still when talking horsepower.. So to answer your last question, it's definitely not drifting or drag racing, or autocross I desire. I'd say between weekend driving, and road racing, kinda like a "cheetah", bursts of insanity when I want, but mostly daily lounging around like if I was driving a KIA lol, so smooth.. With road racing upgrades where does that get me in top speed, because I do miss 155mph! LOL used to have a street bike..ha, and boy did I test that thing..Oh and btw I have to have an auto not a six speed, not because I couldn't find one or preference. Because I had a serious motorcycle accident when I was 23, i'm 28 now, that it put me in a manuel wheel chair..whack I know! Yet kinda ironic considering the manuel thing, ha ha.. But I would install a simple hand control for the Sup like i have now in my current car. I Could always dive anything, "just give me a day", I'd say lol. Used to drive stick shift in my sleep, that was the only way to go but now it's not an option....Anyway, I read that the oem auto tran can handle up to 500hp and no more, true?

Also I read that all systems are controlled by an integrated engine management system (ems), consisting of a main engine control module (ecm) and several peripheral electronic control units (ecu) for the ancillary systems. How does the obdII play into that system, and if I were to upgrade to a AEM ems, how does that work with the rest of the system, i.e. ecu, ecm? Thanks for the response and the help so far btw!

1.can you explain how and where do I get this mixture of higher octane fuel, and is it stored in the main fuel cell together? What is that ratio?

2.why is the exhaust gear more important to adjust, and what is the popular degree(s) for a bpu, say.. 15psi?

3.what are your top 3 favorite fuel systems or the 3 most popular?

4. Complete upgraded coolant and fuel systems past 500hp, but with lower horses I'm ok with oem? flex fuel mix (85)?

5. How does the obdII (on-board dia.) play a role into that Sup's ems system, and if I were to upgrade to a AEM ems, how does that work with the rest of the system, i.e. ecu, ecm?

6. Say I make a bpu where I maintain about 15psi for now, where does the equate in relation to hp?

7. Pros n cons of single turbo and/or twins?

8. Stock auto tran can handle no more than 500hp?

[jzzrs180]

Was looking into a '97, but was also looking at a '94 TT with a great price, the only turn off really was the miles..What do you think?

Current miles: 88,929
1994 TOYOTA SUPRA TWIN TURBO.. BONE STOCK.. ALL ORIGINAL.. NO PAINT WORK.. CLARION CD PLAYER.. LEATHER.. LOW MILEAGE.. FULLY SERVICED.. HANDFUL OF SERVICED RECORDS.. ADULT OWNED.. FLORIDA CAR..

A few little dislikes, one that it has that aftermarket cd player, that it's not a T-top, and I love the '97 front and back ends..minuscule details but would like to hear some feedback. Also any extra recommendations to ask about/look for when buying a car like a Sup? I know test drive and compression test of course.

[Codyjamesuno]

Originally Posted by jzzrs180

Was looking into a '97, but was also looking at a '94 TT with a great price, the only turn off really was the miles..What do you think?

Current miles: 88,929
1994 TOYOTA SUPRA TWIN TURBO.. BONE STOCK.. ALL ORIGINAL.. NO PAINT WORK.. CLARION CD PLAYER.. LEATHER.. LOW MILEAGE.. FULLY SERVICED.. HANDFUL OF SERVICED RECORDS.. ADULT OWNED.. FLORIDA CAR..

A few little dislikes, one that it has that aftermarket cd player, that it's not a T-top, and I love the '97 front and back ends..minuscule details but would like to hear some feedback. Also any extra recommendations to ask about/look for when buying a car like a Sup? I know test drive and compression test of course.

thats low miles if you ask me as long as its been maintained. Looks like a nice find, but the TARGA is an awesome option that I would not go without.

Good Luck!

[jzzrs180]

I hear ya! The targa model ironically weighs a little more too lol, but that's no real matter, definitely would help me make that decision a little easier.. The only real doubt i have though is telling myself that I just put down over $20k on a car that has just under 90,000 miles, and being ok with it.. If I'm patient, I can justify waiting longer, saving up and putting $30k down for one that has 30-40,000 miles, which would make me feel like I'm still buying a new car..But that's where I'm torn, it does look in great shape and it is a good price for the TT..sooo are the miles really that big a deal!? it's an 7 hour drive north if I wanna check it out..

[jzzrs180]

It has a car fax, so that's a plus too, I'm basically jumping all over it, I offered $11k down and have been working on getting everything squared away. I've been busy trying to figure out the best way of going about it, but great advice!! And thank you much for the help. I am going to try to find a local dealership there or import shop possibly that can give me a full inspection! I keep ya informed, and I still want to follow up on our bpu discussion.

[pwpanas]

Originally Posted by jzzrs180

...Somehow that still screams twins to me..!...

The stock twins do spool up fast, but only because 1) they're small and 2) because they operate sequentially. Read more about it here:
http://www.mkiv.com/specifications/ncf/ncf93/ncf088.jpg
http://www.mkiv.com/specifications/ncf/ncf93/ncf089.jpg
http://www.mkiv.com/specifications/ncf/ncf93/ncf086.jpg
etc...

Originally Posted by jzzrs180

...And I heard you can achieve these goals in the 700's still when talking horsepower....

No, the stock twins can't produce 700rwhp. Whomever told you that is 'smoking crack'. If you're talking about aftermarket twins that run in parallel, then sure 800rwhp+ is no problem, but it'll lag just like a big 800rwhp+ single turbo.

Originally Posted by jzzrs180

...With road racing upgrades where does that get me in top speed, because I do miss 155mph!...

The oem Mkiv Turbo is electronically limited to 155mph. With a US-spec Mkiv Supra Turbo, removing that electronic limitation is as easy as pulling the trac fuse.

Originally Posted by jzzrs180

...LOL used to have a street bike..ha, and boy did I test that thing...

Bikes are about as aerodynamic as a brick at 150mph+. You'll find an upgraded Supra exceeding that easily because of the much lower drag coefficient.

Originally Posted by jzzrs180

...Anyway, I read that the oem auto tran can handle up to 500hp and no more, true?...

Depends, but I'd say about 525rwhp reliably. There are upgrades available that will take you to about 675rwhp with the oem TT auto, but to go past that you'll need to swap it out for a TH400 or the like.

Originally Posted by jzzrs180

...Also I read that all systems are controlled by an integrated engine management system (ems), consisting of a main engine control module (ecm) and several peripheral electronic control units (ecu) for the ancillary systems. How does the obdII play into that system, and if I were to upgrade to a AEM ems, how does that work with the rest of the system, i.e. ecu, ecm?...

An AEM ems works fine with ODBI. With ODBII it's a bit trickier - I've heard of some folks leaving the oem ecu in there for emissions, and using the AEM to control the engine.

Originally Posted by jzzrs180

...1.can you explain how and where do I get this mixture of higher octane fuel...

Everything you saw in that wikipedia article is accurate.

Originally Posted by jzzrs180

..., and is it stored in the main fuel cell together?...

Sure. Either that, or you can inject it separately. Your choice.

Originally Posted by jzzrs180

...What is that ratio?...

Depends how much boost you want to run.

Originally Posted by jzzrs180

...why is the exhaust gear more important to adjust...

um, because that's what you need to do to increase the peak hp at higher rpms? The information we've accumulated over the years in this community is thanks to dozens of early pioneers that experimented with the Mkiv Supra Turbo in the mid '90s. Lots of things were tried, and only some worked. The ones that worked were published so it's easy for the rest of us to take advantage of. Again, here's the link:
http://www.mkiv.com/techarticles/cam_gear/install/index.html

Originally Posted by jzzrs180

...Complete upgraded coolant and fuel systems past 500hp,...

No, only the fuel system.

Originally Posted by jzzrs180

...but with lower horses I'm ok with oem? flex fuel mix (85)?...

No, again it depends on boost. More boost, more octane. Forget hp.

Originally Posted by jzzrs180

...Say I make a bpu where I maintain about 15psi for now, where does the equate in relation to hp?...

I'd guess about 350rwhp max through a 6spd. Possibly 325rwhp-ish through an auto.

Originally Posted by jzzrs180

...Pros n cons of single turbo and/or twins?...

Do you mean stock (sequential) twins, or aftermarket parallel twins?

[pwpanas]

Originally Posted by jzzrs180

I hear ya! The targa model ironically weighs a little more too lol, but that's no real matter, definitely would help me make that decision a little easier.. The only real doubt i have though is telling myself that I just put down over $20k on a car that has just under 90,000 miles, and being ok with it.. If I'm patient, I can justify waiting longer, saving up and putting $30k down for one that has 30-40,000 miles, which would make me feel like I'm still buying a new car..But that's where I'm torn, it does look in great shape and it is a good price for the TT..sooo are the miles really that big a deal!? it's an 7 hour drive north if I wanna check it out..

For a '94, 89K miles is LOW. I've seen more than one well-maintained Mkiv Supra Turbo go single-turbo at higher mileage than that, and put out 700rwhp reliably with no issues whatsoever.

That car won't be around long. If it's still available, put cash (not a check!) in a briefcase, get on a plane, and buy it if it checks out. You may already be far too late if it's legit.

Oh, and a hard-top is more desireable: it's more rare, and as you said the lower curb weight makes it a better (GT) sportscar.

Best case, find a local Mkiv Supra Turbo owner that can take it for a test-drive. That way, you'll have an objective, well-informed opinion about the performance, handling, and all of the specific the sounds it makes during the test drive (turbos, transmission, etc.). If possible, find a local shop with extensive Mkiv Supra Turbo experience, and pay them to give it a complete once-over. At the very least, pay your choice of a local Toyota dealership to check it out. It's critical that you get an qualified, objective third party to provide input.

[pwpanas]

Originally Posted by jzzrs180

if a sports car uses increased air (the twins) to increase the cylinder pressure, you would need a high octane gas like 93...

Sorry gotta stop you right there. 93 octane (r+m)/2 pump gas is only 88 motor octane. Rather pathetic, actually. High octane fuel is something like this:
http://www.vpracingfuels.com/page499588.html

Originally Posted by jzzrs180

...to be able to ignite it at the right time, and burn that off efficiently.
But I guess what you are saying is, (if I have you right), that if I were to manage a good bpu I wouldn't have to worry about air:fule ratio because your the ecu reads your increased air automatically and auto corrects your fuel consumption?...

Actually, I'm saying that and a whole lot more. Too much boost using lower octane fuel explodes (i.e. detonates), it doesn't burn...which blows holes in your pistons.

Originally Posted by jzzrs180

...So then, can you explain how and where do I get this mixture of higher octane fuel, and is it stored in the main fuel cell together?...

Yep, or you can inject it separately - your choice.

Originally Posted by jzzrs180

...What is that ratio lol?...

Lol? Tell me the boost you want to run and I'll tell you what ratio to use. Not sure what the Lol is about...it's pretty simple.

Originally Posted by jzzrs180

...sounds like a pain in the ass to fill up..ha....

Not nearly as big a pain in the ass as swapping your pistons out after blowing holes in them. HA!

Originally Posted by jzzrs180

...controlling the cam gears with opening n closing of the valves in relation to TDC is basically how to improve hp, but why?...

Again, you don't improve hp, you just move the peak efficiency curve of the engine so you can make more max hp. You give up a bit of bottom end hp and torque, but that's easily corrected by a downshift.

Originally Posted by jzzrs180

...what are the popular degree(s) for a bpu, with say.. 15psi?...

http://www.mkiv.com/techarticles/cam...all/index.html
"On exhaust gear, retard -3 (deg.), on intake gear, advance 1 (deg.)."

Originally Posted by jzzrs180

...what are your top 3 favorite systems or the 3 most popular?...

To be honest, my favorite was the one I designed and sold, but don't anymore. Sadly, the higher-end components I used didn't allow it to be sold at a competitive price. Regardless, here's one that I'd be comfortable recommending:
http://www.spracingonline.com/store/..._MKIV_Supra/17

Originally Posted by jzzrs180

...And to clarify the thermometer thing, sorry I was saying I thought if you increase your hp past say 500hp that you would have to upgrade your cooling system, which includes radiator, water pump, piping, probably your fmic, and the thermometer, along with the fuel system, fuel lines, pump, filter, injectors..Since the stock system has trouble keeping up with the added power. Am I correct?...

No, I didn't say that at all. Actually, I'm pretty confused about how you could have possibly misread that into any of my posts. Weird. Perhaps you were thinking that a better cooling system would make low octane fuel burn cooler under high boost? If that's the case, then sorry it won't. The cooling system pulls heat out of the metal in the head and the block - which only has a minimal indirect impact on the combustion temperature. Think about it this way - let's say I'm running a Supra in Alaska in the wintertime. The Supra has a single turbo and is configured to push 30psi+ of boost. The ambient temperature is 75 degrees below zero. I fill 'er up with 93 octane (88mon) pump gas and within a few seconds I hit my 30psi of boost. What happens? Of course, this is a bad idea with a cold engine because I'll probably throw a bearing, but putting that problem aside for the moment, I'll still blow holes through the pistons because of detonation. The cooling system is completely irrelevant in this situation, because the metal in the engine is still bone cold. So even with a crazy-cold motor the combustion temperature and pressure and the low octane of the fuel are the important pieces of the puzzle. Get it?

Summary:
Either way, the entire oem cooling system (including the "thermometer" aka temp sensors) is just fine to well over 750rwhp.
The oem fuel system is an entirely different story - the US-spec Mkiv Supra Turbo's oem fuel system can only handle about 550rwhp max - if all of the components are in brand-new condition.

Originally Posted by jzzrs180

...my guess is that it just means better response with your throttle at low and high rpms.. I just wanted a more clear understanding if you could clarify better....

Sorry don't know much about the oem Mkiv auto - hopefully another forum member can help you out here. Mine's a 6spd.

Originally Posted by jzzrs180

...how, and where, and at what ratio do I make this fuel work for me?...

Depends on how much boost you want to run.

Originally Posted by jzzrs180

...Eventually I'd like to hit those higher horse numbers like I already mentioned, but do I have to then switch to a single?...

Yep.

Originally Posted by jzzrs180

...I have seen most nutty 1000hp Sup's (or some with a little less) possess single turbos, but also heard/seen a few that maintained upgraded twins as well, is that unnecessary because of cost to stay with twins?...

You can get "upgraded twins" but they're not longer sequential - they're parallel. Most don't go with this because that kit is more expensive and provides no tangible benefit over a single.

Originally Posted by jzzrs180

...One of my ultimate goals is a strong, quickly responsive powerband all the way through with as little lag as possible starting at low rpm, yet still able to drive it like a regular stock toyota...

Sounds like you want to have your cake and to eat it too. Unfortunately big hp turbos don't spool up fast. It's just physics - a bigger turbo compressor wheel is heavier, and takes more exhaust energy via the turbine wheel to spin up. No one has figured out how to defy the laws of physics yet, so this rule always holds true.