chris308

I will be adding a SC to my LS1 car in the next week or two...

What is the average increase in PSI seen going from plastic dongle from an A&A kit to a 4in pipe?
Its stock with the exception of LS6 intake mani, TSP headers, full exhaust no cats and I'll be using a 3.4" pulley on a V3-Si blower and adding 243 heads.

Would adding the 4" pipe put me at an unsafe boost pressure for my stock engine?

I have a 4" Intake pipe collecting dust; I got it from a friend who used it an his Supra many moons ago. Wouldn't mind using it as long as its not going to rocket my ls1's guts into orbit...

Turpid porpoise

I think I picked up around 1psi going from the A&A dongle to a 4" aluminum tube on my old Ti trim setup. Don't focus so much on manifold pressure, it is simply a measure of restriction. Your engine's limits are more in line with power/torque levels and most will say that 550-600whp is the most you should push on an OEM shortblock.

darsondriss

I have a stock bottom end ls1 with heads, cam, exhaust and a d1sc on a 4" pulley . I swapped up from a 3" tube (round not dongle) to a 4" and think I gained about 1-2 psi to put me up from 14psi to 15.5-16psi. It made 695whp before the intake upgrade so I am pretty sure I am over 700whp now.

silver408z

The biggest problem is probably going to be getting it to fit. I know a 4" intake wont fit with the radiator is the stock position. It might with the way the blower kits lower the radiator some but it might not still.

chris308

I bought the cutdown dewitts rad and spal fan setup, also have the A&A cradle spacers that comes with the kits. I should be ok fit wise, just need to find a reducer coupling for the 4" pipe to headunit.

Thanks for the replies, 1-2psi doesn't seem too bad...