14b

How much boost can a 14b turbo put out and still be efficent and safe? also what happens when you drive a car with no boost control, and on a 95 tsi with a 14b would it be better to get an intake or exhaust first?

around 25psi. if you have no boost controller but hook up the line from wastegate actuator to boost source (manifold, turbo) you will run the wastegate spring pressure... 7psi I believe on t25 and 14b. If you disconnect it totally, it will run to it's max. Intake is cheaper of course, I'd do that first.

around 25psi. if you have no boost controller but hook up the line from wastegate actuator to boost source (manifold, turbo) you will run the wastegate spring pressure... 7psi I believe on t25 and 14b. If you disconnect it totally, it will run to it's max. Intake is cheaper of course, I'd do that first.


Wont the turbo eventually overrun the engine with no mbc? But hey if you are looking for cheap just custom make yourself a 3" turboback exhaust and throw on some cheap filter and bam there you go. Quick question though. I was considering the 14b also and was wondering if it's a bolt on application(to the manifold, the oil lines, the intercooler piping,etc.) Also would a fuel injector and fuel pump upgrade be necissary when only running say 17 or so psi. Thanks :cool:

that depends on what you would consider effecent! there is a veary long answer to that fairly short question. Effency is dependent on boost, and how your cooling the charged air. the higher your effency the more dence your charge will be. the higher your boost the less dence your charge will be. there is a trade off. 25psi is about max i'd run on a 14b, after that your effency will be at 65-70% at best with rpms well into the 160,000+, thats just asking for somthing to break.

intakes do nothing for turbos. the filter is the most important. opening up your exhaust to decrease backpressure and increase exhaust speed will be more benificial.

i've never done a 14b install so i can't help you out their, but i can tell you that your airflow limiter wont let you get to 20psi on a 14b. so unless your willing to buypass it i would have to say no to the extra fuel mods at a "MAX" of 17psi. the airflow wont be enough to out flow your stock fuel system.

actually, without fuel mods, about 14 or 15psi max without getting fuel cut. 17-18max on a 14b but you need an safc and bigger injectors along with a bigger fuel pump(walbro 190 will do) nething bigger then that fuel pump and youll need an afpr

Wont the turbo eventually overrun the engine with no mbc?

What does overrun mean?

actually, without fuel mods, about 14 or 15psi max without getting fuel cut. 17-18max on a 14b but you need an safc and bigger injectors along with a bigger fuel pump(walbro 190 will do) nething bigger then that fuel pump and youll need an afpr
actually no fuel mods are required for a 14b. after all it is a stock 1g turbo and the 450s can cover the maximum efficent boost level on a 14b.
can leave the fuel pump alone too but it wouldnt hurt to rewire it. :smokin:

ok well on a totaly stock tsi AWD with only a 14b nothing else at all what is the best boost to have it at

ok well on a totaly stock tsi AWD with only a 14b nothing else at all what is the best boost to have it at
cant get much higher than 13-14psi with the stock BOV....but with a MBC and some intake work...i would have it at 16psi.

ok i forgot it also has a greddy type s bov with the 14b and it has a new engine and tranny

quick off topic question. whats bigger/better 16b or t3/t04?

You will only be able to run 15psi or so without fuel cut. If you didn't have that, you could run maybe 17psi on pump gas before knock. If you don't want to buy a datalogging and tuning setup, you will only want to run 14-15psi before you need to start watching the logger.

Short answer because you can search and read for days: 16g (i think this is what you meant) is USUALLY smaller than a t3/t4. t3/t4 only means t3 exhaust side and t4 compressor side. That can range in size from 300 to 700 horsepower.

You guys kicked ass in this thread, I'll just add a couple details. :)

The 14b can only hold 25 psi to redline. Like a T25 dropping boost over 5k rpm. At this point efficiency becomes a non-issue, you are not even on the map at this point. And this is regardless of actualy pressure ratio. You are off the map to the right, at whatever boost you are at (dropping as rpm goes up). On pump gas and a sidemount, the most I could get away with was ~18 psi. On race gas I ran one into the 12s on the stock pump and injectors.

A required 2g pump will suffice. A 1g pump will not. A 190 would be recomended though ;) 450s in a 2g will result in 90% IDC. Something that I rarely bring up though is that on 1Gs, base fuel pressure is lower, so the injectors flow less than what they are rated at. Injectors are almost always rated at 43 psi, a 2g has 42-43 psi base pressure, right on. A 1g however is ~38 psi. So 450s behave more like 417s. IDC in this case will go up to 97%. Still sufficient however. By the way, if anyone else is using the spreadsheet on my site, I have added this fuel pressure thing to the calculations, its now a user defineable field. Both base pressure, and rated injector pressure. ;)

Keeping boost (therefore airflow) lower will allow you to run smaller fuel parts, but I like to have the pump and injectors be able to cover the MAX a turbo can put out, to protect the motor in the event of an overboost condition. More on that on my site too.

The spring pressure on the Mitsu turbos is 9-10 psi. So running a vac line from a boost source to the WG actuator will result in this boost pressure. It will only go higher if you get boost creep. And you will, with a larger exhaust, and no porting of the turbo. More on that on my site as well.

A boost controller shouldn't even be called a boost controller. The WGA is really what "controls" boost. We should be calling the MBC a Manual Boost Raiser :D All it does is prevent the boost signal from reaching the WGA until a certain pressure, at which point the WGA does the actual boost control once again.

on my 91 gsx i replaced the fuel pump with a wahlbro 255 lph, had a custom exhaust built so i can run an open header at the track, uicp kit, no interior, pushing 21 psi on 110 unleaded race fuel, and the rest of the car was stock..and pulled an estimated 12.9 in the 1/4. i say estimated since the actual run was done on a 1000ft track. i tripped the lights at 93mph and had a 1.8 60 ft time as well.

with very little mods u can fly!

I'm looking at a 95 TSI AWD 5 speed white/black pewter leather interior 96xxx miles on the body and 58xxx on the engine 14B turbo upgrade greddy type-s bov invader front facia 17" exel rims invader wing sun roof, fully loaded and thats about it and the guy called me the other day and said he'd sell it to me for $4500 how cool is that? Also what could i run for numbers in that as far as boost, hp, and things like that?

well for boost that you should run , re-read the previous....about 15-16psi on 2g injectors. who know what kind of horse power you might be pushing. im guessing, more than stock. im not very good at benchmark dyno tuning.

Thanks for all of the answers it's helped alot, and I'll probably be back for more :p