[iwitarsa]

hey guys i need some opinion... i think i'm changing my turbo plan

right now i have this


i wanted this:


but after seeing this:


i changed my mind...

here's why...

I overlaid the 3 graph


confusing huh??

so to make it clearer i did some photoshop:


you see???

I love torque, especially when it peaks at 4000 rpm. Dom 3 doesn't get me close to the torque of the TD06-20G + meth

380+ wtq on mustang i think its pretty crazy... so i think I'm not going to do the bigger turbo

The thing is i only want to fill up with 91... once and a while if i have to add meth + water is no big deal for me.

what do you guys think? I think you'll feel torque way more than hp, especially on the street.

I kinda worry running 23psi though... stock is 14.5 psi, that's 8.5 psi over stock, even with a great tune do you think the stock STI block should

be ok?? Don't want the engine to break.

I know I'm just being anal... but think about it the STI engine is designed for 300hp/300wtq crank and 14.5psi. Now 332whp/382wtq on mustang,

which is about a freaking 450hp/500tq crank (assuming about 25% AWD drivetrain loss) @ 23psi. THAT'S 150HP AND 200LB-FT OF TORQUE OVER STOCK, IN THIS CASE THE EJ257 IS RUNNING OVER 150% OF ITS DESIGNED POWER OUTPUT.

considering physics, and plain common sense... the engine life must be greatly shortened!!!

if it is shortened, i just want to know by how much is its life shortened. My STI is now at about 35,000miles... been running Stage 2 since

15,000. If i do this turbo + meth upgrade now, the engine life will not pass 50,000 miles right?? Then i'll have to get an upgraded block.

What do you think????

thanks to Stames_wiltz and POPOFF from NASIOC for their dyno graphs.

[ebo03]

Why have a Dominator 3 that is only pushing 19psi? Look at STI-LOS member journal and you'll see what you need. He's over 400 whp and ft/lbs of torque with a Dominator 3 and meth. He was also able to stay with a TMIC and the stock block. Pretty impressive if you ask me

[LSE]

330whp is fine for the stock block. I wouldn't sweat it. Remember subaru knows people tune these cars so it isn't that weak that will blow up after a mere 330whp. With the proper mods and a good tune it shouldn't break easily.

Now if you beat up on it daily, yeah it will break, but so will the stock.

yet for a 20G plus meth, that's kind of a low figure. I'd expect around 350+whp from that setup.

[Flycaster]

First, you cannot compare one dyno to another (trust me, they all use different calibration and load factors, even on the same dyno type). Secondly, unusually big, lumpy, mid-range torque peaks are often the result of initial boost spikes and/or big timing: beware. Third, no one here, or anywhere else, can tell you how long your motor will last at any given power level, period. If you cannot afford the big $$$ to rebuild the motor when and if it dies, do NOT modify it any further; otoh, if money isn't an issue, go for it.

Last, you're already a customer of PDXT, so why aren't you asking them this question? Those guys know more about this than anyone on this board, with the exception of other tuners - give them a call.

[13onesti]

Originally Posted by ebo03

Why have a Dominator 3 that is only pushing 19psi? Look at STI-LOS member journal and you'll see what you need. He's over 400 whp and ft/lbs of torque with a Dominator 3 and meth. He was also able to stay with a TMIC and the stock block. Pretty impressive if you ask me

you cannot compare dyno numbers

hell even on the same dyno on a different day it will read differently


peak dyno numbers are worthless......

[ebo03]

Originally Posted by 13onesti

you cannot compare dyno numbers

hell even on the same dyno on a different day it will read differently


peak dyno numbers are worthless......

Totally agreed. But we also know the sweet spot of the Dominator 3 is not at 19psi

[reid-o]

Although very similar in principle, it's not just the horsepower that's the issue for the stock internals; rather it's the cylinder pressures and the heat created created by such high outputs. Most will tell you that properly tuned you can run reliably at high hp levels on a daily basis, and they're right. The issue is the proximity to knock threshold at the high cylinder pressures.

What most people are alluding to with borrowed time is the likelihood of a freak detonation event at high load--which if you're a betting man, you'll know your chances become better as more time passes. Tuning at these high boost levels and high outputs is irony in action. You could tune air and fuel conservatively to ensure reliability and lower your proximity to the knock threshold with the weak cast parts. But then there's a point where you may as well just lower the boost pressure altogether. But it's USUALLY not the fatigue that kills the block or the mileage that ensues. It's just the chance of a freak occurrence increases as time passes rather than decreases. And when it happens the ring lands probably wont survive.


I havent really heard of fatigue failures on the EJ block, but I've experienced on other cars. Stuff like rod bearings going at high rpm over time, or in my case, the rod itself letting go can be associated more with fatigue and sheer hp levels, regardless of whether the combustion events were knock free.

[STI-LOS]

As was said I made 427/433 with a DOM 3 and Meth with the APS TMIC but it was on a DYNOJET so ofcourse its gonna read higher then a Heartbreaker. For me the DYNO is just a tool I dont put any stock in dyno #'s its cool to get the dyno sheet but thats it.. With that said I would get the actuall numbers thing out of your head, with the right tune you can run the high boost and have the high HP and TQ and the stock block is capable of handling the power.. But like was said there is no telling when something can go wrong and that goes for a built motor aswell, I know my tune is safe and I got tuned at 24psi which is not even the sweet spot of the DOM 3 when I retune this Tuesday with the new HKS controller I will run 25 psi and it will just be a road tune cause like I said I could careless about the dyno.. I know my tuner is very conservative with the timing and the Meth is helping me aswell. If your only looking to run 21psi I would not suggest the DOM 3 it needs higher boost, you can try the GT52 which makes more power on lower boost but I dont see you having a issue with running 24-25psi on your stock block considering your motor is healthy to begin with.. Its a question for your tuner to see what he thinks but to see those #'s on a mustang your gonna have to run higher boost then 19-21psi..

But even though I did a comp test and was 145 straight across, and I am anal on the oil changes and use very high quality oil... I am running high boost and running Meth I am playing the game so if you play you kind of have to be willing to pay.. And even though I dont want to do the motor right now I am saving up for it and by the winter I will sleeve it out and do pistons and rings etc etc, for my Q16 race gas map and 100% Meth and hopefully 500+WHP with a TMIC..

[FlyingPerformance]

What turbo are you running? What turbo do you want to run?

two turbos at the same PSI are NOT going to yield the same power. Why? Because every turbo puts out a different CFM of air flow. 20 PSI on a VF39 and 20 PSI on a GT30R is a way different CFM. You cant compare PSI on one turbo to PSI on another. You also cant compare dyno plots from one dyno to another because to much stuff changes from day to day/hour to hour.

If you want torque, you dont necessarily want a Dom3 because it is slightly laggy because it is a larger turbo. If you like the power the TD06-20g makes, look at a TD05-20G, it will spool faster(because of the small hotside) and make more torque than a TD06, but it will limit your high end power because of the small hotside. There is always a trade-off in spool vs. top end power.

[Flycaster]

If we're talking about great torque, terrific spool up, and good top end, the GT30R with the smaller hotside (.63 a/r) has to be considered. I know, i know...all the tuners say that hotside chokes flow, but I drove one for over a year before I was finally talked into swapping out for the larger hotside, and I miss the mid range performance envelope. In fact, I'm probably going to switch back - the mid range hit is friggin unbelievable.

[ninjaboy76]

Like Flycaster already said, its hard to know how long your block will last. Any upgrades beyond stock are a risk and generally push the car beyond its intended design. The most important factors to longevity are the tune, maintenance, and driving characteristics.

[STI-LOS]

Originally Posted by FlyingPerformance

What turbo are you running? What turbo do you want to run?

two turbos at the same PSI are NOT going to yield the same power. Why? Because every turbo puts out a different CFM of air flow. 20 PSI on a VF39 and 20 PSI on a GT30R is a way different CFM. You cant compare PSI on one turbo to PSI on another. You also cant compare dyno plots from one dyno to another because to much stuff changes from day to day/hour to hour.

If you want torque, you dont necessarily want a Dom3 because it is slightly laggy because it is a larger turbo. If you like the power the TD06-20g makes, look at a TD05-20G, it will spool faster(because of the small hotside) and make more torque than a TD06, but it will limit your high end power because of the small hotside. There is always a trade-off in spool vs. top end power.

The DOM 3.0R is pretty fast spooling, I am hitting full boost at 3800rpm and it should be quicker when I get it re-tuned probably around 3500rpm my VF39 was hitting full boost @ 3200rpm so its not laggy at all, also if he wants TQ why would the DOM 3 or a GT52 or any 52lb turbo not be his choice.

As for the TD05 its a waste you will make no power with it and the diff in spool up is about 200rpm which is not worth the power loss. All in all the OP is looking to make 380 on a Mustang the 20G is not gonna get him there.

[FlyingPerformance]

It is not always about top end power. With the TD05 his power band would be pretty far left on the dyno plot, but would not be that high. He said he wants crazy torque not necessarily crazy HP. He said he wants 380 WTQ, not HP. I am making 300 WHP and 340WTQ on the VF39 without meth, with meth I would be right at 330 WHP and 380 WTQ if not a bit more, with a really fast spool. He would be probably best off sticking with the stock turbo and doing Meth and seeing how he likes that.

[iwitarsa]

Originally Posted by FlyingPerformance

It is not always about top end power. With the TD05 his power band would be pretty far left on the dyno plot, but would not be that high. He said he wants crazy torque not necessarily crazy HP. He said he wants 380 WTQ, not HP. I am making 300 WHP and 340WTQ on the VF39 without meth, with meth I would be right at 330 WHP and 380 WTQ if not a bit more, with a really fast spool. He would be probably best off sticking with the stock turbo and doing Meth and seeing how he likes that.

I think i might just go VF39 + meth first and see how i like it.

Thanks everyone for all the info, again i like torque more than hp, so top end for me is not as important.

I want to break about at least 320whp on mustang, but torgue, I want it more than 350.

I think VF39 with meth might get me close to there, if it's not enough then i'll get the 20G, but definitely no more bigger than that turbo.