You guys are really giving a good demonstration of why you should talk to a tuner BEFORE you start choosing parts. Two tuning sessions and you’re still throwing more parts at it.
Wish you hadn't changed the intercooler (at least for this dyno session). I was specifically looking for a comparison of the G25-660 .72 vs .92 AR which this is not since other variables changed.
Guys about the overheating issue, the bigger intercooler may helps a little bit, but the best solution for subarus for long track sessions will be a hood with heat extractors especially in the radiator fans area.
As a fellow Subaru member I would recommend being conservative and not doing the turbo. It wont make for a great daily. However as a viewer of your channel I want to see a Bigger Turbo. MORE POWER!!!!!!!!!
Have you guys even driven the car with .72 housing? I have the exact same setup on my car and on the street is amazing making 7psi at 3100rpm and 14.5psi by 3900rpm. I hope you guys dont lose too much low end power with the .92. I just hate when people are so hung up on peak numbers and lose on the low-mid range power.
7psi at 3100rpm and 14.5psi by 3900 sounds awesome especially out of 2.1L. When do you start making boost? That .72 sounds alot more fun on the street for that engine size!
GDT or IAG cylinder 4 combustion chamber cooling fix. helps lower the temps on cyl 4 by increasing coolant flow. Did it on my STI build, really helps keeps temps down, and doesn't overload the cooling system.
isnt this supposed to be a nice daily driver. boost at 4500 doesn't make for a great daily so putting on a GT35 sized turbo and pushing the boost rpm out to 5000-5500 is only going to make it worse as a daily.
I have a GTX3076 on my STI, on a fairly conservative tune it made 410 wheel (20psi) on pump and 500 wheel (24 psi) on E85. Comes on at 4k but makes peak power at 7300. Could be a good option for them, its a not too large where the lag is a noticeable issue but its for sure big enough to make power all through the rev range.
Borgworner's are big and bulky, as they have all the waste gate, boost control and blow off valve all incorporated - which is an advantage, but a disadvantage at the same time. Don't forget that all these YT channels use Garrett turbos cos it seems to be the "it" thing. I personally think they're an OK turbo, as they're small, but hefty on price. Myself, I'd probably go for a Steve Murch Holset - NZ guy who ports turbos.
Killer b Equal length headers are the best! Also upgraded fuel pump, fuel rails, and bigger injectors to help with that IDC. Maybe a Grimmspeed or Cobb Electronic boost control solenoid.
If back pressure is opening valves then the exhaust valve springs are week. It’s not the turbos fault. Clearly it seems to be limited to an exact pressure. That’s turbo flows 58 lbs a min. That’s as much as efr7163. They easily make 500 plus. The fk8 civic type r using a g25-660 which has a.72 AR with same turbine wheel doesn’t have this issue on a stock engine. This is a built motor. It’s more likely Intake valve float not exhaust. Unless your exhaust springs are so week the pressure doesn’t stay in the exhaust and then you’ll get a rapid increase in boost pressure with an immediate drop in powered at that point. Looking at the graph power drop off is rather abrupt. Turbo fall off doesn’t look like that valve float does. Going to bigger turbo isn’t gong to fix valve springs.
Here's another SR20 on E85 with the smaller g25-550. Does 485-500 whp. E85 will make about 75hp more over pump gas. I think this EJ20 is having fueling issues. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1s-zMy2x_n0.html
What’s the change in IAT temperatures? Old intercooler: New intercooler: 25 degrees increase per pull. But I didn’t hear the baseline number. Solid numbers, though.
He said the run last time there was a 25 degree increase but on the new intercooler on the preliminary tune there was no increase in charge air temperatures.
the lag may be more obvious down low, but the enlargement of the turbo will ultimately give you more powerband if you can really rev it out to 9k. the operating range would be moved up. id say turbo and headers.
Drive once as-is and decide on header after. It’s a good mod to do, but it’d also be good to see progression. Subaru does a great job at making most of their newer turbo cars underwhelming (they’re very smooth!)
Equal length headers, agree. I think the turbo you have on there should be sufficient. Those newer G series turbos start doing their "magic" at very high boost pressures and flow. To take advantage of that I think you need different cams, cam springs, and some light head work. I wouldn't bother with bigger valves, they weigh more than the stock ones any may encourage valve float at high RPM's. The stock cams are clearly outside of their power band when you are revving over 7.5K. If you can rev the engine up to 8.5K+ you should do that. Keep that spool zone in the 4.5K zone. I think A bigger turbo I think will just make things worse. I have driven many STI's, that have been heavily modified. They are basically on/off switches when you go with bigger turbos. It is a very frustrating driving experience especially if you cant rev very high. If you don't want to run E85 all the time a good option would be to install a water meth injection kit. Make sure you do a direct port manifold (one nozzle per runner) meth injection ONLY, any other way is to inconsistent especially if your port to port air velocities are not equal. If you are still unsatisfied with boost response a trick I have used in other builds I've done is to use a 75-100 shot of NOS until the turbos have a chance to fully spool. I single bottle used this way can last a while since it is only used to help spool.
That drop in power at top is most likely from the cam profile, more specifically the cams duration. More cam duration shifts the torque curve higher in the rpm band. A naturally aspirated engines power curve should amplified under boost.
what i did for fog light holes in the past was open the light take the lens , paint it black and use contact adhesive to stick it to the bumper and cover the hole
3:45 This isn't called rebar. Rebar is the steel lattice structure that's used to reinforce concrete. This is either a box section structure, or something more specific around its usage, like a cross-mount.
Go with the ELH, tune again then check out some lap times before spending more money. I think at this point driver skill and "no fear" additude will have a bigger impact on lap times than HP with a larger turbo. Remember usabe torque wins races.
I have a precision 6262 with an upgraded turbin built by Treadstone that was only used for their dyno testing. Its available for sale along with the rotated turbo assembly from Treadstone.
shanes Matson thank you so much for your answer! 🤩 Based on this I‘m going for the 550 with .72. I have a lot of mountains and tight corners, and for this is my build.
I need to show this to people that doubt my claims of getting ambient temps on my 2.8T Saab 9-3. I have re-routed pipes that dont hug the motor anymore and a very efficient DO88 big intercooler. On long hey pulls its barely increases 10 degrees F
+1 for Killer B ELH if you don't mind staying at the power level but want improved spool and reliability. I think for warranty reasons, you have to get it coated. No wraps allowed, might ask Chris at KB. If you're going full send, then KillerB ELH + big turbo! I wouldn't worry about "turbo lag" or daily drivability because STIs have never been known for low end power. Gotta rev it out, that's why they're manual trans only!
2.1 stroker carrying power to almost 9k? Good luck with that. Should have stayed with a 2L or a 2.34L. You're also going to need larger cams and a GTX3076R. The g25 has such a tiny turbine wheel.
What sort of headwork was done on the car? It almost reads like a head flow issue. A larger turbo may still be a good answer, but perhaps the exhaust side just isn't flowing enough air?
@speedacademy i think you should look into the intake manifold not many subaru intakes are designed to be efficient at high rpm they all flow better in the midrange to increase torque numbers, my suggestion is get more high rpm specific manifold
@@Mortalomena yes turbo is tiny but you are not familiar with g25 line up? they are even using 660 version, those things are capable up to 600 hp (name 660 refers to max hp output, of course there are variables). But i have to agree that this subaru is still just lightly modded
@@ERK77VI Keep in mind that's the crank number not the wheel number, crank hp at 660 would be about 530 wheel on a Subaru, so they are still falling short of the maximum potential, but not as much as it seems at face value.
Hey guys awesome video! May I suggest that you get a killer B header. I have one on my '05 Sti installed it couple months ago and what a difference, the motor is very responsive on each gear shift. I had a perrin equal length header for many years and it's a good header and you lose that subie rumble which is fine because it's all about performance but, the killer B you get the performance and keep the rumble. Thanks guys. 🤙
My top 3 sauces at the moment. Dirty Dicks (mildish 30k) Torchbearer Garlic Reaper (Hot 600kish) Puckerbutt The Reaper (1mil, pure Reaper sauce, no vinegar, amazing)
Change out the turbo while you’re changing out the exhaust manifold & up-pipe you will have to remove DP anyways to have access to the up-pipe which gives you easy access to the turbo. Think about going ewg also... Brake dicting for the fogs and open up the holes on the greddy lip, as it sits its useless 👍🏽 Add a Verus Engineering front splitter already!
First issue I ran into when going big power is you gotta upgrade to T bolt clamps for all the intercooler piping mine keep popping off on track and at auto cross. . I know this is an old series but just my 2 cents.
i have a Garrett GT28/60rs turbo for my ej207 subaru tmi std exhaust manifold 3inch system 565 cc injectors it will run up to 8,200 rpm but starts at 1,800 rpm and pushes all the way some times out accelerated off the line then good bye ! thank you.
I think you definitely need a bigger turbo. Heavy head work and an ELH will increase the flow . The “flat four rumble” is not even current tech. It’s just the sound of the inefficient past.
Just take it to the track. I don’t want to wait 3 more videos while you install another header/turbo, get it tuned for the third time, etc. Let it rip man!
Equal length header is the big upgrade I would want. I wouldn't want a bigger turbo because on the street this turbo is where it would be enjoyable. Yes you can make more power, but will you be able to really enjoy it day in day out like this turbo with the equal length? The equal length header will make the it sound much better as well. You can hear when it revs right now where the length is different cylinder to cylinder and that make it sound Harley like.
header forsure. I would track the car with an equal length header. If you feel the car is still underpowered, then upgrade the turbo. That’s just me but seems like the smart route
@@thomasellis7625 by "significantly less weight" do you mean lower mounted? Because the Honda K20A2 weighs 30lbs less than an ej20, and shits all over it in power and torque numbers at significantly lower boost levels.
@@thomasellis7625 a good set of equal length header weight similar to aftermarket unequal header... My syms racing header weight almost nothing to stock unequal length header
Id just throw on a decent ELH header set up from killerb or Fullrace and give the dyno another go. The car will rip with a little bit over 400whp. Going with a 3584rs would require rotation and a new fuel system. I would see if turbo parts canada could modify the housing to flow more. a 15+ sti steering rack would be another nice piece as just about everything on that car has been changed.
The thing is....Why the rally STI or Nur Challenge STI even the Nur Specail STI is top mount intercooler but not the front mount one.I think the biggest overheat issue is not all about the intercooler ，it help but not that much.Power is not every thing ，U need wide power band.
Surely it doesn't matter if the hot or cold side is next to the exhaust. The intercooler will always reduce the temperature by X amount due to it's size and the speed at which the air passes through it so if the air is 10C hotter entering it will be 10C hotter exiting. In both scenarios the ideal solution is to insulate the pipes as much as possible to prevent extra heating (as you did with the gold tape) but the fact it's the hot side next to it on the COBB kit is irrelevant.
I think turbo is good for the street. You guys should just try make the car reliable. Upgrade fuel system and equal length headers will give you back any rpm/spool lost in .92 housing. Enjoy the car and drive it.
If it were me, and I would be dailying this vehicle, and not just a track toy; I would leave the turbo alone, and throw in a equal length header. Yeah, some extra top end power with a larger turbo would be cool, but how much lag is that going to introduce? I'm curious to see how much of an improvement a EL Header will be. You might not even need the bigger turbo afterwards. Alternative Idea: EL Header + Upgraded TMIC.
