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RoastBeefCurtain Commando
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Discussion Starter · #1 ·
Just curious is anyone here is pushing the limits with stock fuel?
I have a LEX AFM and stock 440's and thats it and running 14-15psi on the stocker and still a little rich under full boost. 11.7-11.8 or so.
I know I will need to upgrade fuel very soon, but I am curious how much leaner i will go by dumping a 60-1 ct-upgrade in for now. If I can just run a little lower boost and still make some decent power without getting too dangerous.

Anyone out there running upgrades on stock fuel?

Just curious.
Discuss. . . . .
 

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TheFastCoonAss
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One would think the logical thing to do would be to spend the money on injectors instead of an upgraded turbo:dunno:

Why would you want run an the ragged edge? You definitely aren't gonna prove anything, just taking a chance of wasting another one!
 

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My dad's daily driver is a 91 MK3 with exhaust, intake, Spearco, EBC, and 57 trim CT w/ no clip. He runs it at around at 10-12 psi with no problems. The Spearco helps a lot even at that level and it does hit fuel cut every once in awhile.

11.7-11.8 is just about right. I wouldnt' call that rich. I never tuned a car leaner than 11.8 at MOST for street driving.
 

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upgraded ct's are like timebombs. they make good power, but only for a matter of months. it took me destroying 5 of them to get another turbo. my advice is keep that thing at stock boost, and get another turbo. (and sell that problem to someone else) or, keep that one for six or so months and destroy it and have to spend another 500+ oh well, its not like i know anything about breaking an upgraded ct.
 

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RoastBeefCurtain Commando
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Discussion Starter · #5 ·
This isnt a CT timebomb thread. I run 14-15 psi everyday and no probs. So dont tell me to run stock boost or it will break. Just like LEX AFM and stock injectors couldnt be done. Well guess what I am doing it now fine.
I am not concerned with that.
Iam concerned with fueling with the upgrades.

11.8 is on the rich side, but not too rich. I could still run a little leaner though and be safe.
I am not saying i wanna push it. I am just curious if anyone has gotten a little ballsy and saw how much leaner it will go. I will be upgrading atleast an SAFC real soon, but was prob gonna get the turbo now and I have an SS elbow coming in today.
If it goes leaner, I can always run a little less boost on the upgrade until i get the fueling done.

I just wanted to get an idea here. It seems like there is alot of heresay here, and everyone is scared to try things. So automatically when something like this comes up , everyone says. Man this guy is crazy screw him.


Trent, Do you happen to know what kinda AFR's your dads is running at? Just to get an idea
 

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I ran my car with the upgraded CT-26 on stock fuel/stock AFM for a while while having most of the other supporting mods including frnt mount IC and pipes.. I only boosted 12psi max. Felt like a dog at that boost level.
 

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Dude, I wasn't saying don't do it and I surely wasn't trying to bash on the upgraded CT. Back in the day when I had the stocker, I ran it at 15psi for over a year before it finally went. It was just old and had been pushed too hard.

I haven't really got a clue what AF's he runs dude. I know he's on stock fuel and AFM though.

But truthfully, if you do want to try it, I might at least try to get the 440's cleaned and flow tested first. That's why so many people have problems with doing things a little on the "crazy" side. The parts they are using aren't setup right or aren't running right and thus problems occur. Give it a shot and see though! I'm all for being experimental and seeing what happens.
 

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RoastBeefCurtain Commando
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Discussion Starter · #9 ·
Sorry I shoulda clarified . I was talking to Rajunz and Juhanis.

I dont like to be forced into cookiecutter setups as much as possible.
I like to try new things sometimes. Just curious on certain things.

Like everyone says you cant do an atmospheric BOV becuase it runs too rich between shifts. . . .How rich ?
Guess what I know how rich becuase I was curious and tested it.

Everyone says you cant do a LEX AFM with 440's, will go too lean. . . .How Lean?
Guess What,I know how supposedly lean. And guess what, its not lean.

So I just wanted to get a concesus of Ideas of who has done what with this just for reference.
I will likely replace the injectors and put an SAFC on just for safety, but curious on if anyone tested exactly how needed it was right off the bat.

Trent as always you are a great help and I always appreciate your words of wisdom. That comment was more for the people who always jump on my threads when I post something to get an idea on something that doesnt seem to be discussed.
 

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Certified Supra Nut :P
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WARNING

The stock fuel pump can only supply enough fuel to support about 300rwhp. If you're near that level or plan to go over it, upgrade the pump. I saw fuel pressure drop while using 550s on the stock pump at full load. took me a while to figure out what was going on. Play it safe, get a fuel pump. It's easy to tell when your injectors can't flow enough becasue you can measure duty cycle and afr, it's not so easy to tell when your pump runs out of steam.

Cheap insurance
 

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RoastBeefCurtain Commando
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Discussion Starter · #11 ·
really the pumps will only supply 300whp?
No biggie its only an $80 upgrade. Just a pain in the ass to get to

But yea I was planning on doing that with the SAFC at the same time prob.
 

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well, afr's um, the only time i ever really measured mine was with a cracked piston (i found out later) on the dyno. they were about 11.8:1 and i was making 335hp 364tq with a 60trim upgraded ct with no clip @ 16psi. the problem piston during that run only had 70psi of compression at the time of that dyno. the boost was at 20psi when it was running on all six. i had 550's and an safc (@ -24% at the highest), and a walbro pump. those were the only major fuel mods i had. i also was running ngk copper's that were one step colder. do fuel mods... its not worth boosting without them. i should have ran race gas... thats probably why my pistons are cracking. i've cracked 1 and 6 both on the intake side, and both on the ring lands. point is, its better being safe. pulling the motor to fix crap like that isnt fun.
 

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RoastBeefCurtain Commando
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Discussion Starter · #13 ·
obviously I would have done it in steps and closely watched everything. I was just curious as to really how much leaner the turbo would make it.
I might end up buying a new IC and SAFC and fuel pump before the week is over instead of buying the turbo.
I guess Ill see what I can do with my setup now
 

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I have a 57-1 ct-26 controlled to 10-11 lbs of boost. I wasnt aware there could be any problems with doing this. Next thing i plan on doing is 550s and lex afm tho, and getting it tuned, but then i also wasnt aware that that is pushing the stock fuel pump limit. damn.
 

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TheFastCoonAss
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Juhanis said:
................point is, its better being safe. pulling the motor to fix crap like that isnt fun.
This is the only point I was trying to make. Not to rag on you, but what you currently have is a half assed setup, you have no way of controlling air/fuel ratios, you don't have any way of controlling fuel pressues, and basically what you have done is jury rigged your own FCD to get past fuel cut.

So why don't we add just a little bit more velocity to the mix until we totaly max it out? And the question you ask of us is how much more can you push it, sorry if I fail to see any logical thinking here..........................and the purpose of all this is so that you won't be called "Cookie Cutter" :dunno:

Perhaps what you are viewing as "Cookie Cutter" are the results of lots of logical thinking, safeguards and previous owners trials and errors.
 

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RoastBeefCurtain Commando
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Discussion Starter · #16 ·
But is is really trial and error. Or someone coming on here saying you cant do it this way, so everyone do it my way.

Yes I agree my setup might not be optimal, but for the mods it has it is safe by all means and it moves extremely well considering.
My next move was fueling, but I really dont need it yet. I keep an eye on my AFR's and they are perfect. I couldnt ask for better. Matter of fact, id prob lean it out a hair.
I just ordered an IC and doing hardpipes.
After that I will be getting a fuel pump and prob an SAFC and cleaning and balancing my stock injectors. We will see how it all goes.
 

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all a ct upgrade with stock fuel will get you is increased lag with a little more pull before you hit fco/boost control limit. It just starts to pull hard around 11psi, so stock fuel isnt really sufficient. As for how long they last, ive had a ct upgrade for the past 2 years running 12-15 psi with no issues.

adam
 

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i dont know, maybe i just pushed mine too hard. i drive my car real hard, but i do maintain it. oil is changed every 1k miles or so, at least once a month. and i dont drive it THAT much. i agree on the it pulls after 11psi... it gets real fun around 18, over 20psi is just pointless unless you got some wide tires on there. i had mine at 22psi and it was smoking the tires all the way through 3rd. from a roll at around in 3rd @ around 60mph, it would spin the tires. oh well, i've destroyed too many of those to keep em. i went with something with beefy internals.
 

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I don't want an MK4!
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That cookiecutter shit you referred to has also been tested and proven.

Is it the only way? Aboslutley not.

Is it a safe and conservative way? Absolutley.

Reinvent the wheel if you want, but don't complain about folks that go with the tried and true.

My cookiecutter mods have yielded me a car that makes over 100 more RWHP than when I got it a year ago. I am only running 12 PSI on the stock CT-26.

The car runs just like stock in everyway until I climb on the gas.

Don't whine about people using proven methods to increase power on the Supra just cause you want to save a buck or two.

If you can come up with something inovative that works, then more power to you!

Dan

Edit-To clarify. These cars are old. Most ideas have been thought about, tried, and though they have worked for some, are not the best way to go. Folks like JBL are an exception. I could have went the route as well for my goals, but said "fuck it" and had the proper parts installed to be safe.

Most of the people looking to get the extra power out of their cars need to first put them in excellent operating condition.

They are old cars and standard parts will need to be replaced.

I am interested to see how you end up going your way. You sound like you understand the basic maintence thing which so many on here don't.
 
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