[GXPinGNV]

Just got a Solo high-flow cat and DDM charge pipes. What's the generally accepted limit for boost? I have heard 25 PSI but I don't necessarily want to push the risk of damage to the limit.

What consensus can the group provide? Thank you in advance.

 

[rob the elder]

The car is designed to make 260 ft pounds of torque. Unless you have a tune, it will always work to produce 260 ft pounds. The high flow cat can add 16 to 18 HP but with the factory tune, it will adjust to get back "down" to 260 ft pounds. The maximum boost level is a function of air density, humidity etc. A car that is at sea level will "need" less boost to achieve 260 ft pounds at sea level and more at altitude. For example, 12 pounds at sea level and 18 pounds at 6000 feet.

If you have a tune, generally they will change the target torque value to allow the car to produce the added HP resulting from the high flow cat. With the GMPP tune, we have seen 16-18 pounds of boost at sea level and the same car 24-25 pounds of boost at altitude.

Unless you have a failure, or the tune is bad, the car should not produce enough boost to damage itself.

Look for the Flashes Owner post on the GMPP tune which does a good job of explaining how the tune works

 

[The_Ghost]

The OE Intercooler (IC) are a weak point. They can split at anything over 20psi. Many have had this issue. If the IC does hold to 24psi, then the turbo is too small and just becomes a heat pump after 24psi with a factory IC. And then that introduces knock which the LNF does not like, nor does it last too long with knock. Also the turbo can usually only push no more then 24psi as the seals just won't hold. I'm dyno tuned and pushing 24psi with the OE IC. The tuner programmed my fan to come on 100% at 190 degrees so that it would cool the IC because running it on a dyno produced too much knock with all the heat.

If you want to produce the most hp out of the LNF, a HFC, IC, CAI and IC piping (and 3BAR MAPs) along with a dyno will net you about 375hp. While the stock components breathe enough for the K04 turbo, it's about the heat that those stock components breathe. The latest edition of the LNF (LTG, found in ATS, CTS, Camaro, Envision, Regal, Equinox, Terrain, Malibu...) is capable of over to 400hp with those mods and a dyno tune.

 

[wspohn]

If you want to produce the most hp out of the LNF, a HFC, IC, CAI and IC piping (and 3BAR MAPs) along with a dyno will net you about 375hp. While the stock components breathe enough for the K04 turbo, it's about the heat that those stock components breathe. The latest edition of the LNF (LTG, found in ATS, CTS, Camaro, Envision, Regal, Equinox, Terrain, Malibu...) is capable of over to 400hp with those mods and a dyno tune.

I doubt that you can get to 375 bhp with a stock K04 turbo, no matter what tune you use. Think it requires a change in turbo or at least a changed (larger) impeller on the K04.

 

[The_Ghost]

I'm at ~335hp right now, which is the 286hp at the wheels with 23psi (sorry I said 24 earlier). Another 2psi of boost would get me well over 350hp. And then add a HFC and an IC and i think I would have been close to 370hp. He had me over 350hp and backed me down because of heat.

 

[rob the elder]

With the GMPP tune many cars produce /5 pounds of boost reliably. In the early GXP production there was a batch of charge air coolers that were not manufactured correctly and the fin to tune mechanical connections were weak. They would balloon and fail. I believe the number of failures was very small. A few intercooler cans cracked as well but I have not heard of any boost related failures in several years