Safe boost level for stock turbo with PW TMIC

[fahr_side]

One thing you're not understanding is that it's the stock downpipe that limits the boost you can run safely.

The turbine spins and drives the compressor when there is a pressure drop across it's blades. The more backpressure there is in the downpipe, the higher the pressure has to be in the up-pipe to get to any given boost pressure. There's a limit to how high pre-turbo backpressure can get before you get into reversion, high exhaust gas temperatures and detonation.

For these reasons, stage 1 tunes are sensibly limited to 16~16.5psi while stage 2 can go to 18psi or even higher.

 

Get yourself a downpipe and a pro stage 2 tune. Stage 3 is great, and you have the intercooler for it, but you will need to beef up your transmission.

[DerekDaniel]

Ok yeah the down pipe is gonna have to wait. well you think I can run 17-17.5 psi with stock turbo and downpipe with tmic upgrade and be good?

some people said I could go up to 18 I don't know about that.

[DerekDaniel]

Why not an Invidia DP with Invidia CBE?

 

I had a cobb before and had good results plus I am a "brand ho"

[famaya26]

Ah your a brand guy. Well good luck with your car man, hope you have a blast with it.

[fahr_side]

Ok yeah the down pipe is gonna have to wait. well you think I can run 17-17.5 psi with stock turbo and downpipe with tmic upgrade and be good?

some people said I could go up to 18 I don't know about that.

 

*sigh* I just told you why that's a bad idea. Don't get so hung up on boost pressure, it's just a number. When your EGBP climbs too high, you'll have to reduce timing to avoid det. As Sprankle mentions, you get to a point where your timing is so low you'll make less torque than with lower boost and more timing.

More boost doesn't always equal more torque or power!

 

Also vote for Invidia DP. Very high quality, widely copied.

[DerekDaniel]

I am not trying to squeeze out max boost by doing this I think my post got misinterpreted and misconstrued.

 

I want to know max boost levels to achieve them but to know what is safe psi, or what would be max acceptable range be for that setup. I dont care about price or other mods. this is what I am working with at the moment. I was just trying to establish a baseline off of other peoples experience with similar setup or with stock tmic and what boost levels were they running.

 

But this dang post took a wrong turn when some ppl got wrapped up in price and thought I was doing this too hit 20 psi lol

NO I am not, its because my stock tmic cant handle 17 psi and I dont trust it to either, so I upgraded, maybe a little over kill but oh well thats just me. I want to hopefully achieve and maintain at least 17 psi boost. So i asked for advice because I didn't want to short change myself if more could be safely squeeze out 1 more psi with this setup.

[fahr_side]

We see people get fixated on the wrong things all the time, or miss the big picture. Gotta have 20psi mang = psi-head. Gotta have 320g/s airflow bro = cfm-head... and so-on. While there are no hard and fast limits, many cars behave in the same way and some baselines can be established. Let your tuner decide which is better for your hardware setup, more boost or more timing, richer or leaner, for best performance with reliability. If you don't trust your tuner to make those choices find another, or learn to tune yourself.

 

FWIW the PW is a really nice part. Yes, it's overkill for a stage1 setup, and for most stage2 setups too, but the fact is you have already. There's probably some jealousy at play here too.

[DerekDaniel]

We see people get fixated on the wrong things all the time, or miss the big picture. Gotta have 20psi mang = psi-head. Gotta have 320g/s airflow bro = cfm-head... and so-on. While there are no hard and fast limits, many cars behave in the same way and some baselines can be established. Let your tuner decide which is better for your hardware setup, more boost or more timing, richer or leaner, for best performance with reliability. If you don't trust your tuner to make those choices find another, or learn to tune yourself.

 

FWIW the PW is a really nice part. Yes, it's overkill for a stage1 setup, and for most stage2 setups too, but the fact is you have already. There's probably some jealousy at play here too.

 

Thank you thats why I rarely get on nasioc because people get strung up on irrelevant matters and offer no real contribution other than confusion. I like this forums lol now it feels like an interrogation.

 

I am new to the tuning process and I buy expensive parts. I do not like the cheap route as prior experience I have learned it gets you no where. So please offer advise on what can be done, not what I should have done based on projected and displaced emotions or subjective opinion. Be a contributor.

 

Thank you fahrside and yes I will go by my tuners advice. I just cant overload my tuner with every question. So i post here trying to learn. I was just trying to gather data to educate myself during this process. So I can have a good tuning experience and have a better understanding of the mechanical/tuning process. Thanks gents.

[fahr_side]

Fair play. I don't think you're an idiot but you were starting to do a good impression of one type of idiot that shows up here on a recurring basis. A lot of n00bs show up here either wanting information fed to them on a silver spoon or demanding validation for their incorrect beliefs / bad decisions. A lot of the heckling those people get is actually in their best interests, even they don't see that. Glad we're over that now.

 

Recommend you go over to romraider.com and read some of the stickies there to educate yourself about the tuning process, strategies and gotchas. Most people here are happy to answer questions from people actually reading and learning, so if there is more stuff you're confused about just ask again in this, your very own tune / mod thread.

[seabass07]

Just stick with 16-17psi until you do the downpipe. As has already been mentioned, the intercooler was never the limiting factor. It was the downpipe that kept you from hitting the targets the tuner was going for. If your tuner told you to get a new intercooler because you couldn't go over 17psi with a stock downpipe, you should be looking for a new tuner.

[bmx045]

subscribed

[DerekDaniel]

Just stick with 16-17psi until you do the downpipe. As has already been mentioned, the intercooler was never the limiting factor. It was the downpipe that kept you from hitting the targets the tuner was going for. If your tuner told you to get a new intercooler because you couldn't go over 17psi with a stock downpipe, you should be looking for a new tuner.

 

Yes I have since switched tuners:) Thank God. But I like the PW set up and it will serve a bigger purpose hopefully sooner then later lol.

Yes my old tuner is long gone I am filing a better business report on his A@@ he told me I couldnt go higher psi also, because I did not have a 3 inch mid pipe on my cat back (it is 2.5inch) so that restricted back pressure and blah blah blah. Well he never tuned a legacy before so I told him to please stop I am not stupid and he is not experimenting on my car. So I left his shop with an unsafe tune took a few datalogs and parked the car. Got the infamous tune and so far I am happy with it. I popped the bpv hose at 17psi. So I got It back on with clamp and I decided to just get a top mount since everything was removed and my oem unit was crap. So I am trying to get my ride back up to par. I am waiting on the retune for the tmic and hoping all goes well. thanks for the support.

 

I have printed off fom raider info cobb info and google stuff all day trying to learn more it was kinda hard earlier I just finished 3 summer classes now I can work on my supplemental tuning/car education.

[Pako]

So far (it's only been a week), I have ran with a Stage 2 tune from Infamous1 and haven't popped anything off. Currently set at 17.5 Peak boost on my stock TMIC. I have plans to "Bullet Proof" it as soon as I can as a precaution. Not too long ago, I was thinking the same as you and almost pulled the trigger on a PW myself. I am still toying with the idea and go back and forth between that and a FMIC. I really need to decided how far I want to mod "my baby" that is also my daily driver. With a busy schedule, I can't afford to be constantly working on the car. A "project car" isn't something I am looking for, but safe and reliable performance is appealing.

 

Best of luck with your PW IC. I still might go that route, a FMIC is just so damn sexy, it's hard not wanting to go that route.

[DerekDaniel]

here is a log from my previous protune done by chad at modified by KC. This is why I am trying to learn because had I driven on this and not had a little education from all you good people on here I probably would still be driving with that tune and have a jacked up car. My new logs look nothing like this erratic mess

23July log4 sport sharp pull.csv

[paintpollz]

Best of luck with your PW IC. I still might go that route, a FMIC is just so damn sexy, it's hard not wanting to go that route.

 

i have an FMIC, yes they look nice, but they can be a PITA. I have constant fmic woes. I will say the performance is very impressive.

[bmx045]

not good

[DerekDaniel]

here is a log from my previous protune done by chad at modified by KC. This is why I am trying to learn because had I driven on this and not had a little education from all you good people on here I probably would still be driving with that tune and have a jacked up car. My new logs look nothing like that erratic mess

 

Yes fahr side i understand what you say about reducing the timing to run more boost this is a perfect example lol. I told the guy that my car felt like it had less torque and like the boost was carrying the car more he continued to give me some more fairy tales.

[DerekDaniel]

i have an FMIC, yes they look nice, but they can be a PITA. I have constant fmic woes. I will say the performance is very impressive.

 

This is another reason why I didnt do fmic, its install scares me lol not to mention ripping off my front end I am not even a shade tree mechanic lol

[DerekDaniel]

So far (it's only been a week), I have ran with a Stage 2 tune from Infamous1 and haven't popped anything off. Currently set at 17.5 Peak boost on my stock TMIC. I have plans to "Bullet Proof" it as soon as I can as a precaution. Not too long ago, I was thinking the same as you and almost pulled the trigger on a PW myself. I am still toying with the idea and go back and forth between that and a FMIC. I really need to decided how far I want to mod "my baby" that is also my daily driver. With a busy schedule, I can't afford to be constantly working on the car. A "project car" isn't something I am looking for, but safe and reliable performance is appealing.

 

Best of luck with your PW IC. I still might go that route, a FMIC is just so damn sexy, it's hard not wanting to go that route.

 

Yeah that my bpv line was the only hose that did not have a clamp on it. well it has a worm clamp and ziptie now. plus my bpv was missing its gasket I have no clue when or how that happened. Former tuner neglected to catch it. The car is all prepped for the PW and I am changing out pcv valve while its opened up too, and a new bpv gasket on its way too. So after its all done in said I hope all is well.

[seabass07]

Glad it's working out!!

 

You could always gut your downpipe if you felt so inclined. You'd be able to run the range you're looking at. Should be able to do 18psi without any boost control issues on a gutted stock downpipe. It's also free, other than an afternoon of your labor if you have some tools.

[DerekDaniel]

Yeah I could but I probably wont because I just would rather get a DP designed for that. I will be getting a down pipe eventually, atleast I will have a suitable TMIC for it when the time comes:) I am debating on which one invidia seems quite popular I had a cobb before on other suby and really liked it.

[m sprank]

Seems the gent like the good stuff. If he has the money, why not? He is also planning on future upgrades, so while the PW is technically a bit early, it will get used in the end.

 

Invidia are very good quality. There are a few copies of the Invidia out there and that says something (it is good enough to want to copy). Cobb is also very high quality. I am not the biggest fan of the 2.5" step down (or the high price). I have owned and used both. For the money, Invidia.

[fahr_side]

You could always gut your downpipe if you felt so inclined. You'd be able to run the range you're looking at.

 

Been there, done that. You can run higher boost but boost control is very choppy and spool is a bit late compared to a proper bellmouth type downpipe. Despite leaving the second cat intact, my bumper was quickly stained yellow-brown. You get what you pay for.

 

Love my Invidia catted DP. Quality and fitment are great.

[.Catalyst.]

DD - I too prefer the high quality parts, and sounds like you're on the right track. Your first couple posts did confuse me, but I get where you are going now. My apologies if I misunderstood and came off condescending after reading you went PW, Inlet, EBCS, and CBE and were going for max boost on a stage 1 VF40 build.

 

I've heard really good things about the Invidia stuff, and agree with MSprank on the Cobb DP regarding the 2.5 taper (unless you plan on the stock mid/y cans for the foreseeable future). I went TurboXS full 3" catted for my DP, which has great welds and is a nice piece, (although my local Subaru performance mechanic isn't real keen on their flanges vs. Invidia or Cobb) and will mate it to their upcoming CBE and ditch my 3" to 2.5 adapter.

 

I'll probably go with the PW as well (although I'm anxious to see the Grimmspeed piece as I doubt I'll go with a Turbo that will really ever require the massive core). I spent months researching and compiling parts for my stage 2 build, and haven't skimped on quality (Grimmspeed, TurboXS, AVO throughout). I'm huge on quality/fit/finish and hope to only have to buy parts once as long as I'm doing it right!

[DerekDaniel]

Yeah I may go cobb route, because I have a straight through 2.5" mid pipe at the moment.

 

Is there a significant advantage of a 3" mid pipe over 2.5" mid pipe connected to 3in DP?

Like in Cobbs case, would it be ok to run 3" to 2.5" and staying at 2.5" for mid pipe instead of going up to 3" , and still get good performance and gains?

 

Or, would a straight through 3" DP to Mid-pipe (No 2.5" taper) be the best for performance and gains? Which I am assuming Invidia is 3" DP staright through no 2.5" taper...?

 

Is Invidia open bell mouth?

 

I had a Cobb to SPT setup before, and always wondered about the 3" DP with a 2.5" tapered connection on to a 3" mid pipe.

 

It just sounds funky. Once the air is restricted at 2.5" at the end of Cobb DP a 3" mid pipe, would seem unnecessary or ineffective to go up to 3" because of the 2.5" impeding flow.