ca18det, hks 40mm & T518z (wont boost)

[Dan1200sss]

finally fired up the new ca today, everything seemed great until i went for a drive, drives like a non turbo almost haha. boost gauge reads 20 vac off boost and then only gets to 0-1psi on boost. got the hks wastegate plumbed in, and im running the side barb fitting back to the first section of intercooler piping with vac line. no boost controller is installed. the springs meant to be 7-8psi i was told but yeah i dunno whats going on? any ideas? turbo is a genuine greddy T518z.

[Sideways s12]

Sounds like a massive boost leak or maybe a defective wastegate i'd check for boost leak first

[boost_boy]

I'm with sideways on this one. Sounds like issues with your wastegate. I use the HKS 40mm gates and I've been down that road where they don't boost, but it's usually in the area of internal failure from the wastegate. If you mounted it wrong (flange upside down) it's not going to boost. Too many things that can go wrong with those; and if you bought it used, good luck with that. Furthermore, where did you attach the wastegate? If you attached it to you your downpipe, then you fail. I say this because I've seen this before with similar results as yours.

[float_6969]

Are u running a MAFS? If so, then a boost leak big enoug to cause these symptoms would also keep the car from idling. Even w/a MAPS setup, IDK that it would still idle well.

For these reasons I would say the more likely scenario is a bad exast leak, which you would easily hear, or a problem with the wastegate. If the diaphram in the wastegate fails, there is little to nothing the keep the valve closed in the wastegate and you'll get little to no boost.

if it were my car, I'd pull the wastegate off and dissassemble it to check for problems. i also have an HKS external wastegate, so if you take pics, I'll be able to tell you if there any problems.

[Dan1200sss]

Ok so I thought fukit I'll splash out and get a new tial MVS gate, installed it and gained only 1-2psi. Now she's hitting 3-4psi max (has a .7bar spring in it)so Shud be 10-11 psi right? It idles fine and drives smooth as! Maybe it's because I'm plumbed into the dump pipe ?

[boost_boy]

Ok so I thought fukit I'll splash out and get a new tial MVS gate, installed it and gained only 1-2psi. Now she's hitting 3-4psi max (has a .7bar spring in it)so Shud be 10-11 psi right? It idles fine and drives smooth as! Maybe it's because I'm plumbed into the dump pipe ?

Brotha man from the 15th floor, read the last sentence of my first post and re-evaluate your car. Purchasing the tial gate was a waste of $$$$$. The HKS units are very reliable under serious boost and I trust them more than any other; especially with my precious toys .

[Dan1200sss]

So why don't they work when plumbed back into the dump pipe ? I'm new to this sort of thing haha

[sjbsuperman1425]

Is your wastegate mounted before the turbo and then plumbed back into the exhaust using a dump pipe?

Post a pic of your setup.

[Dan1200sss]

Will do tonight. Yeah it's mounted to the exhaust manifold at the collector, then plumbs back in after the turbo a few inchs down the dump pipe.Other than that..maaan does she sounds good, doesn't even have any lifter tick !!

[sjbsuperman1425]

is it possible you have the wastegate mounted backwards? (ie. the flange that should be "dumping" to the dowpipe is mounted to the exhaust manifold?)

[float_6969]

that would keep it shut all the time and he'd make crazy boost. It has to be an exaust leak, or an improperly installed wastegate. Try removing the vac line from the wastegate. It should make at least 12-16psi, maybe more. If not you've got an exhaust leak, or you did somethign screwy with the wastegate.

[sjbsuperman1425]

yea Ryan's right..idk wtf I was thinking..

[float_6969]

Ofcourse I'm right [/azzhole comments]

[Dan1200sss]

somehow it seems to be fixing itself slowly getting more boost, its getting to around 8-9psi now. havent changed anything at all either haha. oh well so almost no problems now. man it pulls hard on 8psi! cant wait for 20psi after dyno tune

[float_6969]

Hmm, was the wastegate used? Maybe there was some debris on the valve stem or valve seat that wasn't allowing the valve to close fully. Regardless, I'm glad to hear you've got it worked out.

[r34 gtr]

So how do you like that turbo? I am curious because I have bought the same one for my car, whenever I get it running again.

[Dan1200sss]

So far so good, pulls like what I'd imagined it to really. Really smooth power curve. Iv got a Greddy t67 il prob put on her later this year to really get things screaming. But yeah this turbos is a good turbo for a ca.