18 psi BOOST

[rodpaslow]

I've been reading, a bit of time at work today on the TDI website.  I'm a bit concerned as they suggest that cylinder pressure is too great if you boost more that 18 psi at sea level.  They have several warnings about this for a TDI.  I will have a intercooler (water to air) before my car is running.  Is this an issue for IDI cars as well, or because of the precombustion chamber we can handle more boost?

[smoken u]

im no expert on this but 18 psi seems low to be concerned about cylinder pressure in a TDI. TDI's have lower compression than IDI's so should be able to handle more boost than an IDI which has insane compression, as long as your intercooled i cant see why you couldnt run a bit over 20 psi on a TDI with possibly an upgraded turbo seeing as those little vnt17's cant handle much lol. 

[GEE-BEE]

Iam running 17 psi, 1325 temp on Egt....

No problem's

GB

[RabbitJockey]

maybe on a stock tdi

[carrizog60]

used to run above 30psi max boost and the engine was ok...

[OM617]

18psi is too much for the turbo. The engine can easily handle more pressure.
Above that it will be spinning too fast, the same concept as running your engine at 6000rpm.

[Rabbit on Roids]

what turbo is on your engine? i used to run 30+ out of my VNT..

[OM617]

i used to run 30+ out of my VNT.

I doubt it was the factory VNT15.

[Rabbit on Roids]

it most definitely was not a stock VNT 15.. it was a VNT17.. and yea, it made 30 psi just fine. really starts screaming about 25 psi..

[OM617]

really starts screaming about 25 psi..

They usually do when oversped.

[dts67]

Read that too but lets be under no illusion, any tuning is going to increase the pcps but most seem to get away with it.

[Rabbit on Roids]

really starts screaming about 25 psi..

They usually do when oversped.

it was oversped because of extremely retarded timing.. it doesnt scream or make 30+ psi anymore..

[rodpaslow]

I don't have a TDI, but I was reading the faq in the form that said 18 psi max.  Mine is a 1.6 TD with a air to water intercooler with a T3 turbo (supposed to be a 92 engine) that has been fully rebuilt engine with arp fasteners for the important bits, metal hd gasket, etc.  I was wondering for longevity if 18 psi was the max.  It sounds like from the replies it can handle much more.  If the T3 will do it, I'd like to run about 25 most of the time - no special reason.

[8v-of-fury]

25 most of the time will mean you are pumping in a significant amount of fuel, your EGT's will go up and your wallet size go down..

too much fuel and heat is deathly to these engines and is what causes damage, not boost. However boost is relevant to amount of heat, which is relevant to amount of fuel.. 20psi is wayy more than enough to have loads of fun while maintaining longevity.