With the stock greddy kit I was seeing 5psi all the way up to redline. After installing stripes kit it starts to drop around 4500 to only 3psi by 6500. I was thinking for now I could just tee the wastegate to the manifold instead which should fix the problem.
Does anyone know why I get the drop?

 

If you had the stock greddy kit with no intercooler, just installing one will lower your boost, not sure if it will account for a drop that large, when i installed mine i lost about 1-2 psi with the intercooler. Check all your hoses and make sure they are tight the pressure might be creating a little hole at higher boost that is causing it to leak.

 

Yep. Ic's usually have a psi drop. Some will cool the air better but lose more boost, some will not lose so much boost but not be efficient in its cooling job. Like if you go to an ebay IC and scroll down, theirs a chart and usually tells you the psi drop and cooling effiencys. I think im right?

 

check for leaks.

Take a spray bottle, fill it with soapy water, hit all the connection points. Rev the motor and look for bubbles.

 

2 psi of drop over your IC sounds like a leak to me. Where is the boost gauge hooked up? Do you have the WG rod tighetned all the way?

 

I'll check the pipes with soapy water as I do have a bit of a questionable connection where I used a coupling from the stock greddy kit. Boost gauge is hooked up to the manifold directly. And the WG rod has been tightened nicely. I do get a solid 5 psi until i go WOT after 4500-5000ish then starts to drop a bit so I was thinking it wasnt a leak. But I could be wrong.

 

The WG signal line to the manifold might help with your problem, worth a try. Vac tubing is cheap enough anyway.

 

Don't laugh, but take a tennis ball and stick it where the sun don't shine (in your exhaust pipe). Plug up your intake as well and put 10PSI on the entire system. Then just put soapy water on EVERYTHING (IM where the fuel injectors connect, etc). If there is a leak you will find it.

 

Hook up your vac line to your mani for the wastegate. 1-2psi pressure drop is normal.

P.s.- I have a MBC for ya if you want it.

 

Yup, check all your coupler connections. Sounds like a leak to me.

 

Well I tried the soapy water but I cant seem to make enough positive pressure without any load to check for leaks.
I'll take a shot a tightening up all the tbolt clamps again and double check everything.

and BTW stripes, the kit was nice. Well worth the money IMHO.

 

i have the stripes kit also....but only have a 1psi drop. will hooking up my waste gate vac line to the manifold help out on the psi drop?

 

no, intercoolers cause pressure loss. That's just the way it is.

so all you have to do is compensate for it. add 1 psi of boost and wa-la, no more loss.

 

Yeah I checked and I dont see how there could possibly be any leaks. So mani to WG for now, MSnS w/ EBC when I plan to up it. Sounds good

 

manifold to wastegate isnt going to change the pressure drop. Even at stock boost levels I'd suggest a $10 MBC.

 

No? I figured the wastegate closes 5 psi. It may be hitting 5 psi in the compressor housing but by the time it gets to the manifold it's dropped a bit after 4500 rpm. If connected to the manifold then shouldnt the wastegate close again and raise boost if pressure drops below 5psi?

 

mbc would still be good to have man.

 

Yes it will. If the wastegate is set for 5psi without an intercooler, adding the stripes kit doesn't change anything, except give a pressure drop on the other side of the intercooler.....what his boost guage is seeing. Guaranteed, (leaks or no leaks) that he will be running 5psi again if he changes his vac/boost line to the intake mani. If you aren't hooked up this way, I suggest you do......because it also increases your power band. The turbo spools quicker to compensate for the pressure drop and delays the wastegate from opening too soon.

Dedoky: You'll also need a rubber cap to clamp over the turbo vac/boost port where you original "blue" line was for the wastegate.

 

correct, me have brain fart. Just trying emphazise that a pressure drop will always exist in the pipes.

as far as source line, I've heard vacuum isn't great for wastegates. a MBC will solve the wastegate from opening too soon.

 

Pressure drop will always exist after installing an intercooler, but running the wastegate actuator signal off the intake manifold will recoup your "missing" PSI, dedoky (assuming no leaks, etc.).