Safe amount of boost on stock engine?
 

Anyone know what might be a safe amount to boost on a stock engine before having to build the internals?

Just weighing the option and prices for now.

I dont think anyone knows. if you boost at the levels the tunes come in i would say thats safe.

All depends on your tune , kit and the way you intend to drive it

My estimates from hours of lurking around here

10~ on 91
14~ on 93 thanks to king tut
16sh on 9X + WMI
20+ on e85

Obviously this is the amount of boost, you have to consider fuel issues , drivetrain and cooling

My 1 cent :mad0259:

Thanks. At least this can get me in the ball park on what to aim for. I think I'm going to aim at 8psi for now to be safe. Later on probably higher if I want to change the internals I can always crank it up.

I think on 91 ( your location says CA) you'd be fine with 7sh 8sh

I'm going boosted On 91 and e85 soon hopefully, i'll stay low for a month or two until I throw some low cr rods and pistons.

I heard via the ecutek and haltech networks of a few cars throwing rods around 300 whp! :eyebulge:

Apparently it's just a load limit on the rod when it sees bursts of extreme accel.

There's a lot of big number charts on here but how many of them saw extended, high load use outside of a dyno room?

If I'm not mistaken a fair number of them have seen a decent amount track and Drag use at 250+ whp

Water/Meth injection seems like a good option if you have limited access to E85 or want to wait on building the motor. Ptuning is pulling 400whp on 93 and meth injection on the stock block. More than enough to get you in all sorts of trouble

While many people on the forum or the internet may throw this out and around. Personally, I do not enjoy the idea of E85 neither do Meth injections. If I was to do this with my VR4, she would break 550 AWHP.

Meth Injections = Rusty part + 70% more for catastrophic failure (Not practical for every armatures )

E85 = Very few fuel stations, and the Fuel consumption is 2-3x times more of the traditional 93. Your full tank of gas may just serve you 1/3 of the original mileage range

The best possible is to build a car running on 93, with conservative tune.

The good news is that with 93, and running around 10 PSI will have you in the range of 300-350 RWHP already. This already makes this car into a beast

True, speaking for my self Im aiming for the 300 mark on e85 before I build my motor with a simple rod piston setup.
Aren't you pushing 3xx whp on a stock block @nix ?

Yeah with about 40% DI to port, over rich map and extra squirts of fuel at points for cooling. I wouldn't expect them to last at this power. I don't really want to go with a flat top head and lose the swirl atomisation of DI so waiting on options.

im on 93 and 5.3 psi at 286hp and with exhaust close to 300 if not 300 so its very safe because i beat it up. next week or two ill be on 10 psi pump and e85 so hopefully ill be around the 400++ so ill beat that up and tell you if its safe also but it should be lol

It is really more of a three variable equation with two primary variables. The two primary variables are boost and timing and the third is your air/fuel ratio. For a given boost/timing/afr there is a maximum brake torque your car can achieve. For most turbo cars this is a few degrees of timing before knock occurs although it can also be past the knock threshold and be unachieveable at a given boost level. So in reality you can either run more boost and pull more timing or run less boost and run more timing. The fact is that knock becomes the limiting factor. Running a richer afr can help move this knock threshold a little bit as well which is why it is a lesser variable in the equation.

It seems most people on this site are not really that interested in the timing that cars are running as compared to the boost that they are running. The cars making good horsepower numbers on lower boost levels are going to be running considerably more timing. You throw in some E85 or meth and again you are going to be running considerably more timing. To get the total picture of how a kit is running you would need to see dyno plots with horespower, torque, afr, boost, and ignition timing.

TL;DR: There is no correct answer to your question.

who ever has the better tuner lol pretty much ^^

This is a good example. Somehow FA20Club has found a way to make 22hp per psi. You can bet that he is running considerably more timing than I am at 14 psi, but he didn't say I am on 93 at 5.3 psi and 25 degrees of timing.

my goal is 400 didnt say i would reach it but i would love to hahhaha

When tuning a boosted car there are the two different mindsets I mentioned. The fact is that with our 12.5:1 compression and 93 octane, we are severly knock limited and the only question is how does your tuner choose to approach that limit either through more boost or more timing.

but dont you think with the compression we have more boost is not really the BEST solution it works fine as your driving with 14psi but lets say i push 10 and make what you make what you think would be the safer option ?

thats part of the reason we chose the t3t4 route for our base kit. small turbos ramp in boost very early with big torque spikes. this is typically the same point any small turbo car will generate allot of knock and spit rods in comparison to the more progressive power found in a supercharger like vortech or a larger frame turbo like our kit. we didnt choose the turbo based on power it was based on minimizing stress on the engine. for a small turbo to make big power its going to have to ramp hard and create that initial spike in torque to do it.

LOL, well naturally i would be running more timing than your 14 psi map but nowhere near your guesstimate. my timing curve is still pretty conservative infact its almost identical to my vortech map. the issue is i can yield more power from a multitude of variables. first my turbo choice moves my power band in a different direction from yours. when tip-in occurs my setup requires less accell pump increases because my turbo didnt ramp up as fast. the timing map can be progressively ramped back in for a smaller turbo whereas retarded a bit more through the band for the larger turbo since it doesnt take as much energy to keep making power through the curve. if i were @14psi with my setup honestly i would be running even less timing than what you would be at with your GT28. for a gt28 to pump out 20+ hp/psi on low boost would be almost unheard of even with the rpm range and compression of this motor.

Thanks for the information. What size turbo is @lexusb3 running again? I know that power per psi is also largely determined by the size of the turbo.

Ouch! That's scary as that's pretty much my goal :bonk:

I'll keep an eye out as I don't baby my car at all. I drive her nuts off, and also plan on going to the track quite often...

How do you get in the "ecutek and haltech" networks? Is that a secret club for ecutek dealers?

T3/4 60

I think you have to be Australian because Haltech is an Australian standalone ECU company that competes with EcuTek. I have ZERO fear of the motor not lasting on 300 whp by the way.

Because boost numbers don't mean much. Might as well be an arbitrary number when you're talking about turbos.
This thread, several posters in it, hell the entire internet make it sound as if there's a magic boost threshold for any given engine where if you stay below that line, you're safe.
It's not that easy. Ever. For any engine. Even for two identical engines made on the same day in the same factory.

Equal powerbands are equally safe for the engine internals, whether you're at low boost and high timing or high boost and low timing. Torque breaks things, fuel washes down cylinder walls, bad tanks of gas blow engines, etc. The boost pressure in the intake manifold is not what determines "safe".

So what kind of timing(in terms of degrees BTDC) are these cars running boosted versus N/A? I always thought you run the least amount of total timing possible to insure a complete burn. Too much timing on an efficient chamber design actually works against you. From what I've read, you want maximum cylinder pressure to occur ~6-10 degrees ATDC.

stock for stocks, 11 psi at 15.5 degrees.

Do i fear for my motor ? no, i keep up the maintenance and it keeps me happy.

this exactly...

the basics...

Your engine can only flow a certain volume of air.
Changing the density doesn't change the volume of air entering the engine.
The density that the air is at, decreases, if you shrink the tubing along the path and increases visa versa.
http://upload.wikimedia.org/wikipedi...enturiFlow.png
Turbine spool rate: faster is always better depending on the flow rate of that turbo and its threshold. high spool rates signify the efficiency of the turbo. aka needs less exhaust pressure to spool. this in turns lets air leave the engine faster. This decreases the amount of energy the engine has to exert to remove the ignited air and fuel out of the engine.

There are 3 places where energy is used in a natturally asparated combustion engine.
1 to turn the drive shaft
2 to evacuate exhaust gasses
3 pulling in air

this is where turbos help/hurt...
1 air is now being pushed into the combustion chamber
2 more air is available for combustion
but
3 they create more internal heat = loss in power
4 the turbine on the exhaust side creates lots of back pressure and when the air heats up from combustion, the volume of which the air wants to occupy increases dramatically making lots of pressure with the turbo holding it back like a damn behind the turbo. this is why a fast spooling turbo is recommended. air moves out faster and the engine has to do less work to achieve it.

gtx3076R is great turbo for this. Quick spool, high flow rate, and a high threshold

http://www.himni-racing.com/images/GTX3076R_comp1.JPG

Now that we have the basics done.

reliability
1. measure the air density and flow rate as close to the intake valves as possible, preferably after the throttle body.
2 find a turbo that flows the best vs the amount of hp you want to achieve
too small and your engine/turbo will have to work harder, too big and you will increase lag and back pressure lower in the rpm band
the gtx3076R or comparable turbo is a great mid point, spools fast with lots of room to grow if you need it and you can rev high with it without running our of breath. also with less back pressure you have less heat and your turbo will run cooler during daily driving doing less damage to itself and all components around it.
3 larger intake inlet before the turbo the turbo will be able to flow more with less work = less heat/faster spool times (this is why the PTuning kit works so well with low boost, notice how large that intake pipe is!)
http://i50.tinypic.com/dg70hv.jpg
4 a high flow/efficient intercooler. This allows the air to move slower through the intercooler allowing more time for the compressed air to cool. and remember above picture, the larger path compressed air has to move through the denser it is = more power
5 think about getting a larger throttle body as an upgrade at some point to relieve the bottle neck effect of air that reduces air density but not too large that it hurts the flow rate a few mm larger can yield some pretty good gains on a turbo set up. also with a larger opening the air is cooler by the awesome means of physics. when you accelerate air through a confined space it heats up.
6 watch those air fuel ratios, keep them conservative. with the set up above you should be able to make the same power as someone with a less efficient kit that is running more boost and timing and be more reliable than them
7 Turbo placement, is the turbo placed where it can do the least amount of damage as it radiates heat, and is it near a place that has a flow of air to cool it?
8 Oil coolers for the engine/turbo oil and transimission
9 use better oils that have the correct additives for your application and last longer. I personally like 15k mile extended performance M1, track days i like motul.

more reliability!
1 have custom pistons made with the same tolerances in mind as the factory (pretty strict) that are made specifically for your engine's measurements.
2 have water sprayers installed to cool your intercooler for hotter days. (just like STI's :D)
3 Titanium valves, springs, and retainers (more heat resistant than stock, but from what I've read the stock valve train is pretty good as is)
4 proper fueling: make sure your running equipment that can exceed what you need so you aren't running your pumps at 100% at redline wearing them out. I've always gone by the rule that the pumps/injectors should be around 60%-75% of their threshold at fuel cut
5 change oil more frequently, like every 2k - 3k miles.( for dd's that never see track time just a bunch of hooning)

even more reliability! (lots more money)
1 get a baffled pan and a dry sump to cure oil starvation
2 sump system in the fuel tank so you don't have fuel starvation issues, if you lean out you could blow up your engine! (accelerated performance is developing a kit!)
3 if you want more power, run e85 and get a flex fuel kit in case you get shit E85 like we do in Texas that not always E85 plus you can just pour 93 when ever you don't feel like running E85 and not have to switch any maps

there's more you can do and there's a million different factors i could go over but i don't feel like typing any more

I hope this clears some things up

so reliably isn't measured in whp

its measured in tq, intake and exhaust temperatures, how efficient the engine flows from the intake to exhaust tips, timing, and are all parts up to the job?

if you build your engine, make it as efficient as possible, and keep up with standard maintenance. I don't see why the engine couldn't last for over 100k miles of daily driving at 400 whp and 200k miles at 280 whp. of course track hours are completely different but it should reflect in the same way.

and to answer the OP question
as long as the kit is efficient, sensors are in their correct place for accurate readings, running a conservative tune and low boost (under 9 psi) your turbo frs/brz/gt86 should last you 100k miles

my last car i modified it to run up to a 9800 rpm redline, beat it for 74k miles putting a grand total of 152k miles on a 12 year old car. and never once had an issue. i raced to work on a bone cold engine ever day during the winter and bounced off that almost 10k fuel cut every day. if you want to turbo. do it right the first time and you'll never regret it.

I'm not turbo yet... why? the parts i want to build my kit with don't exist yet. until the fuel fix with accelerated performance is finished i wont even consider doing my build. good thing flex fuel is though! thanks visconti!

Like for example there's a silver frs in north texas that was turbo'd, it was build, tuned by the right people. and because a catalytic converter wasn't up to the task, it melted and shit itself into the turbo. 1 small part like that that could have been replaced with a much better part and that failure would have never happened.

EDIT: also a water-meth injection kit can also be added, these kits clean the inside of the engine's combustion chamber. ive seen photos of cars that ran water/meth for 70k miles and the insides of them look brand new

i have high hopes for the FA20. with a solid tune i think 8-10psi, 300-350whp on pump gas will last a long while with proper maintenance. considering fbm has countless dyno pulls at 600whp+, daily driving half that, with a good tune (that's the key part), should be plenty reliable. with a shitty tune nothing is safe.

Where's the cliffs? :thumbsup:

:party0030: 10psi soon wooooo!!! Lol

yeah i base my calculations on what has been done so far, a shop that can do 400 dyno pulls at over 400 whp (which has been done i think) holds high hopes for us DD guys who only want 260-300 whp and want it to run for a long time.

cliffs?

The fa20club kit will get you 300 at only 5psi pump so you will be ok long term well at least 6,000 miles cuz that's all I have so far on this kit lol

You sir is one of many people with much knowledge about FI system. I would look after your build to mimic. Now, I am still waiting for new FRS or BRZ to see what TOYO-BARU have to improve. If not, until you Build your, I would buy mine USED, and go the same ROUTE !

Cliff notes, the summary of your post :D


Great post BTW!!

Wow, thanks for the excellent post @carbonBLUE !!!

my build?
EDIT Garret GTX3076R
New Turbo Kit Sneak Peek(Ptuning)
http://www.ft86club.com/forums/showthread.php?t=31218
Accelerated Performance's Fuel System Fix for the BRZ/FRS/GT86
http://www.ft86club.com/forums/showthread.php?t=36231
FBM Billet High Flow Fuel Rails
http://www.ft86club.com/forums/showthread.php?p=905152
PTUNING: PnP Water/Methanol Injection System w/Optional Failsafe
http://www.ft86club.com/forums/showthread.php?t=34654
FA20CLUB Oil Cooler Kit
http://www.ft86club.com/forums/showthread.php?t=35854
racelogic traction control system
http://www.racelogic.co.uk/
B&M ATF Cooler
http://bmracing.com/?page_id=1046
KOYO Radiator
http://www.ft86club.com/forums/showthread.php?p=811571
Ferrea's Valve components
http://www.ft86club.com/forums/showthread.php?t=24283
Visconti Tuning Presents: True FlexFuel
http://www.ft86club.com/forums/showthread.php?t=35787
Custom
Air evacuation/splash guard for bottom mount turbo for PTuning kit

Mahle pistons (haven't decided the compression ratio yet, also i choose them because they like to mimic DI OEM piston design and a lot of research went into our OEM pistons, plus i had them on my last car, no issues)

there are a couple things i haven't decided on yet, like boost controllers, injectors, hpfp, lpfp, ect...

until i've decided on what i want to do 100% im not buying anything plus i need to buy a cheap car for the down time like some 1k civic or something and then keep it around in-case anything ere to go wrong

EDIT:
i will be running about 10 psi at about 310 whp with a VERY conservative tune, if i can achieve it at 8 psi even better. im at low altitude so those goals on the PTuning kit will be had very easily
also as a reminder 310whp on AWDtuning's dyno will be more than it seems (they read REALLY low) i got like 140whp base line there and on another dyno i got about 163 whp under similar conditions

even that im undecided about i may just shoot for 280 and call it a day i dont want a rocket ship but im ready for boost

EDIT EDIT:
many thanks to all the shops and people who went ahead and boosted into the unkown, without you i would not have come to an informed decision on what build i wanted to do!!! :D seriously all of yall rock!
it took 6 years of research in the 2zz-ge engine community before i was comfortable with getting the car and modifying it to my liking. as far as FI goes this community has come futher than most in 1 year than other have in 5-10 years. So much love for this car.
And many thanks goes out to toyota and subaru for giving us an awesome platform and such a strong engine. I had a convo with a few supra guys who's jaws dropped when i told them theres a 600+ whp FRS/BRZ running around with over 300 dyno pulls under its belt, and its on stock internals... that says ALOT.

Nice. You should start a placeholder build thread so I can subscribe, lol.

It's just the tuners talking to each other. Mine tunes on about half a dozen ems brands and they are all interested in the fa20.

I will when i get around to it, ill also be able to report back on reliability because i do drive a fuck ton, give avg mpgs

im at 30k miles already, 3 years after i get the kit ill do a tear down and post pics on how well the engine took boost for 100k miles

i plan on doing a few track days at mineral wells and tell you how it feels going sideways... all in good time... when the parts are ready and im ready ill start my build thread.

ill have a talk with my local shop and see which parts i can do without for those who don't want to spend the full amount but also don't want crazy hp numbers. things like pistons and valves aren't necessary but i do drive my car pretty hard for a DD

I watch and learn from others mistakes.. and ill probably make some mistakes myself... but I'm ready to shed some blood, sweat, and oil again like i did on my last car :D

EDIT: also im looking for that subaru rumble sound... I WILL FIND A WAY! lol