F1nd3r05

Today I thought I might have had an issue with my manual boost controller or wastegate so I decided to clamp my boost line and make sure everything is working. After trying to clamp the line, the car would only go to 15psi. No hesitations, no hiccups, no nothing. Perfect smooth sailing up to 15psi where it just held. Any ideas anyone? Also with the manual boost controller it was at the same psi when opened all the way.

I was under the impression that if you clamped the boost line from the intercooler piping that it should boost way past that if not indefinitely. Here are my modifications.

M44/51
Cross drilled & knifed Forged Crankshaft
Forged Connecting Rods
Forged Pistons
Gates timing and balance shaft belts
Victor Reinz gaskets
Cometic head gasket
Lindsey Super 75 Turbo
Lindsey racing custom J boot
Bosch AFM
Bosch rotor and distributor cap
Bosch spark plug wires
NGK-R spark plugs
Bosch diverter valve
Stage 1 intercooler
SPEC 6 puck clutch
SPEC pressure plate
K&N air filter and custom AFM adaptor
Seimens injectors
Atomic Manual Boost Controller
Lindsey chips to match products above

F1nd3r05

I forgot to add that it also has a turbo back exhaust no cat just a muffler

Paulyy

What brand is your wastegate?
Did you change it or is it stock?

F1nd3r05

It is stock shimmed

F1nd3r05

regardless of what type or shimmed, if i clamp the boost line wouldnt the wastegate have no affect?

rlm328

Only if you crushed the line.

SirLapsalot

What was it doing before when you thought you may have issue with your mbc?

F1nd3r05

It acclerated perfectly at 10 so i kept increasing it gradually and the whole time it accelerated fine. then i got to a point where the more i continued to turn the mbc it stayed at the same 15psi. I then thought maybe the controller was broken so i clamped the charge line with a vice grip and tried to see if it would go past. I assumed that not only by doing this method but that I have a Lindsey Super 75 turbo, that it would boost way over 15psi but instead just maxed out at the same place

F1nd3r05

no fuel cut no hesitations or hiccups still perfect acceleration just no boost increase

SirLapsalot

Maybe the spring in the wastegate is weak enough that boost pressure forces it fully open at 15psi and no more boost can be generated.

F1nd3r05

I guess I'm not understanding. Even with the charge line clamped the wastegate spring can/would still open at the same point?

rlm328

What does your vacuum look like?

F1nd3r05

about 18in/hg

lart951

once the line is clamped the wastegate would open to whatever is the spring capacity, if this is a shimmed stock 15psi is probably right with a tired wastegate the valve is probably opening and bleeding boost, with all the mods you have why would you use a shimmed wastegate, been there done that.

here

https://rennlist.com/forums/944-turb...yno-chart.html


Opppsss, I guess lart was right

https://rennlist.com/forums/11215019-post114.html

all that clarks quoting for nothing, hey tommy boy so who was right after all, lol

F1nd3r05

Thank you for that last post. I honestly am not educated enough to have realized that was the problem. I thought it might be but I just wanted to try and rule anything else out. I read so many post about how with a Lindsey Super 75 turbo that clamped it can produce so much boost that i thought it would go higher regardless but clearly that is not the case. Is there any test I can do to 100% prove that that is the problem? I just want to do something that can make absolutely sure that is the problem before i order a new wastegate. Thank you for your help!