Disconnecting boost tube?

[Phil99TA]

I read about free mods and stuff all the time for stock DSMs but I never see anything about disconnecting the boost tube that connects to the boost control solenoid. All of the local DSMs guys do it but I never see it on the Internet. Is this something you guys do? I'm not sure how much extra boost it gives over stock but I can definately feel a difference.

Phil
99 Trans Am, not stock
91 Talon TSi, open K&N, free mods

[BatmanGSX]

It's stupid. I have done it. Stock boost for me is about 10psi give or take 1 depending on the gear. With the tube disconnected and cut to 18 inches (the length effects the boost) I got 12psi in 1st, 15psi in second, 18psi and then I think 21.something psi in 4th. It was stupid, I wanted the increase in one and two but didn't get it, and by 5th I'm sure it would have been at a dangerous level but I stopped at 4th because because my timing was yanked and it wouldn't pull past 4000rpms in 3rd. Just spend $50 on a Joe P. MBC.

[jfa_16]

i never heard of doing that without a boost controller.

[Silver TSI]

Would it be safe to do that for one run to feel the effects of the high boost? or will it blow something?
Nick

[DSMscreamer]

You can blow something up in one run if the boost goes too high. It is absolutely crazy to run more boost without a boost gauge in the first place because you will never know how much boost your running. What if somhow the boost jumped to like 30PSI? Your car would not feel much quicker because your intake temps would skyrocket and your car would yank all the timing it could. Meanwhile your pistons would begin melting. You might come out OK or you might not. But i would do it the right way with a Boost gauge and MBC. Its cheap to do so you might as well. Or your first taste of high boost could be your last. (until you rebuild your motor which cost alot)

P.S That is a nice looking car. Nice color!

[Edited by DSMscreamer on 05-30-2001 at 05:03 PM]

[Silver TSI]

Thanks DSMScreamer on the complement. I'm to affraid to do it anyhow, I am going to wait for my Guage to come in.
Thanks,
Nick

[BatmanGSX]

Well taking the tube off didn't give me the boost level I wanted in 1st and then was too high in later gears. Most of problems came from the fact that I was running a highly experimental MAS that flows so much it demands an AFC (which I did not have). But I am guessing that in 5th gear my boost would have been about 24-25psi which is useless on a 14B and just too damn high without an AFC, among other things...

MBCs can be had cheaply and will hold 15psi or whatever in all 5 gears. There is no excuse not to have one, I know that now, learn from my stupidity.

[BatmanGSX]

Oh, and as a side note, if your ECU and fuel system is working properly it is almost impossible to do damage to your pistons with the stock turbo, it would take almost 30psi (like DSMscreamer noted, and this is possible if you pull the tube off the wastegate actuator instead of the BCS, probably 28psi) to do it. The computer still has enough control to make the necessary changes to prevent melting pistons with a 14B up to probably 26psi.

[MoBoost]

Well you don't have to melt you pistons - lifting the head can be done with 25psi just fine! Don't forget about detonation - it can break off your valves!

[BatmanGSX]

Originally posted by MoBoost
Well you don't have to melt you pistons - lifting the head can be done with 25psi just fine! Don't forget about detonation - it can break off your valves!

Yup, this is true. Forgot to mention that stuff. But are you sure the head lifts at 25psi? I figured it would be just a little higher... not much higher but like 27-28psi. I could be wrong. Now that I have painted my car I don't toy with death so much (what's the point of modding an ugly car and what's the point of breaking a pretty one?). 23 psi with water injection and FMIC is what I am shooting for.