im cross-posting this from G35driver since it may help some of you 350z guys

i thought id make this thread to document the issues ive had with my APS TT kit since i installed it about a year ago. The APS kit is known for smoking and ive used this forum a lot to help diagnose my issues and hopefully this info will help those who are experiencing similar problems.

so i had a shop named Precision Autosports in Dayton, OH install my APS Tuner TT kit last august. they did the TT kit, APS test pipes and full catback, HKS EVC6, autometer nexus guages, 255lph walbo fuel pump, 600cc DW injectors, and a UTEC to control everything. we initially had problems with the UTEC holding idle so i switched to Osiris and it fixed everything. they made 395rwhp/369rwtq @ 7.5psi.

i noticed after about 300 miles the car would smoke (light blue, definitely oil) a little bit on decel and when i would come to a stop after driving it a bit, but only rarely and only on hotter days. i brought it back after reading about the oil pan drain fix that APS issued. my tuner recommended going with braided nylon hoses instead of the normal rubber ones. they installed those and cut the length to what APS recommended and i didnt really experience the smoke issue too much after that. it would come and go but was rare.

fast forward to about a month and a half ago. it started smoking a lot more often and then i noticed the a/f gauge would spike at 16 when going 40 in 4th or 60 in 6th, basically anytime the RPMs hovered around 2k. then the car would sputter until i gave it some kind of load. under WOT it was perfect. i talked to the UpRev guys and they said it sounded like i had a crappy tune and to get it retuned ASAP.

i found out that the tuner i got to install the kit apparently went bankrupt (which, honestly, was a good thing since they charged me way more than we agreed upon basically by strong arming me :/ ). the closest UpRev tuner was SlowMotion Motorsports in Columbus, about an hour away. i took it to them to get it retuned and we ran into some issues.

he noticed the tune was FULL of timing. he said it was a very aggressive tune and was surprised the motor hadnt popped already. he retuned it and made 400rwhp/365rwtq at 5.5psi. but it was smoking HEAVILY on decel and at idle. like WAY more than before. he gave it back to me and on the way back i went WOT at around 60 in 6th and noticed detonation. it NEVER detonated before. i also noticed it was smoking WAY more than before. i took it back and told him to fix it. he said it seems like by tuning it we exacerbated a previous issue the car may have had. so i told him to do some diagnostics and see why it was smoking/detonating.

that was about 3 weeks ago. they did a compression check and the compression was within 2psi difference. pretty much perfect. then they did a leakdown. the numbers were 1%, 1%, 2%, 2%, 4%, and 9%. he was worried about the 9% and said that could be a real issue and said i might need an engine rebuild. he said the smoke issue could be the ring seals. that or the turbo seals.

now i know the APS kit is extremely sensitive to oil levels and it is also known to blow turbo seals. so i had them work that issue first while i did more research about the possible ring issue. i called Forged and spoke to Decker. he said the 9% was nothing to worry about unless there was oil on the plugs, which there wasnt. it just means the motor is a little tired but its DEFINITELY not necessary to rebuild it. he said it sounds like turbo seals to him. if they werent 600 miles away thats the place i would take my car and there only. i am seriously jealous of you guys near Ga. but i digress.

so i had them remove the turbos to see if they needed a rebuild. they did so and said they looked perfect. however they did say the passenger side turbo oil line to the pan, the one APS did the fix for, was kinked. he said it was almost closed and it seemed to him that it would cause blowback and oil seepage through the turbo seals, but the turbos were COMPLETELY DRY. no sign of oil anywhere.

i read on here that a lot of guys with smoking issues put restrictors on the turbos and that seems to help. so i had them do so and also replace those nylon drains hoses with stainless braided so they wouldnt kink. i hopefully get the car back today and will update on whether the issue has been fixed. in the meantime, any advice anyone reading this has would be awesome. its really embarrassing to drop $15k into your car and have it smoke like a chimney.

 

awesome. just got off the phone with SlowMotion Motorsports....its still smoking. im seriously at a loss as to what the issue may be.

 

Best way with the APS kit is to blank off the aps oil pan returns and drill and tap new returns in the upper oil pan. This means the turbo returns tie in above the oil level.

Hope you get your problem sorted.

Post up some vids so we can see how much smoke your making.

 

how many miles are on the kit? it could be the turbos

 

i dont get it...is it a flawed design? why didnt APS make the kit like that in the first place?

btw how much oil do you run? we have 5.5qts of 5w30 Royal Purple in there now

 

not even 7k

they removed the turbos and there is no sign of wear.

 

I run my car with the oil level between 3/4 and FULL on the OEM dip stick. The block tapping is a little more involved than just putting the turbo returns back intothe oil pan. May be aps was going for an Easyer install?

Also I run a 15w-50 motul 300v comp oil. Try a heavy oil as this should not pass through the turbo seals so easy.

Also make sure your breathing the crank case properly. The oem system does not work while on boost.

 

even with different dynos, this doesnt make much sense... The only way to make more power with less boost is MORE timing.... not much surprise you are knocking.


Like mentioned about crankcase pressure, try putting breather filters on your PCV system to bypass the stock setup. See if that helps 1st.

 

from what ive read, and what APS recommends, is to fill it up slightly passed the L mark on the dipstick which is 5-5.5 quarts.

what does breathing the crankcase entail?
is breather filters an easy install or should i have my shop do it?

about the dynos....one was a roller dyno and the other was a dynojet...if that makes any difference

 

i mean like i said it cant be the turbos cause they inspected them and they were dry as a bone and thee seals were fine. we put restrictors on the lines as well and still smoke.

 

get that rp crap out of your motor too. that oil is way too thin for a TT setup. if you wanna stick with a 30 weight oil go with Castrol 0w30 from autozone if you want to setup up to a bit thicker weight oil go with Rotella T-Syn T6 5w40 from walmart, autozone or pepboys. this wont fix your problem but those two oils will protect your engine a lot better than RP will.

 

i want to go with whatever doesnt smoke

 

If restrictions (on the feed sides) didn't reduce the smoking then the oil lines probably aren't the issue...my guess is either PVC valve or bad turbo seals.

 

I agree with the previous posters in regard to crankcase pressure.

 

Look in your plenum for oil. +1 on crankcase pressure. Read the threads on it... or just put breather filters on the valve covers and see if it all goes away - then read up on it.

 

got the car back tonight...its still smoking. almost nothing on a cold motor or on idle but a SHITLOAD if youve driven it hard and let it idle. like an obscene amount. ill try to get a vid up. its pretty ridiculous.

restrictors are on as are braided drain lines. he also retuned it so its not detonating. i got the compression numbers and they are kind of weird...190 in #1 then the rest are 180. i have a feeling he did the test wrong. they didnt want to do it in the first place until i insited after the leakdown test.

 

also details on PVC valve?

 

is oil in the plenum the smoking gun on crankcase pressure?

 

That is correct...keep it at 5 1/2

 

I had very simular issues and slowmotion built my car. They were right in that the motor needed rebuilding. It took three leakdown test to find a difference in a cylinder...once we had the motor apart, i had two cracked pistons...very minor, right along the rings. Just enough to have blowby under pressure. My first issue was the turbo (turbonectics crappy model) then I swapped it out with a Garrett and didnt have any issues with the turbo anymore.

Corey knows what his is talking about as he has tuned several Gs and Zs...including building a 750whp built motor TT G.

and to address the issues about boost. I am only running 5.5lbs and I have simular numbers. My turbo is larger and with the stage 5 lightweight internals, its spools faster than the old one creating more responsive boost faster.

I went through 6 months of thinking it was the turbo (which part of the problem was) and then finally finding the cracked pistons. Mine smoked a little, then a lot simular to how you described. I hate to say, but it is possible that you have a cracked piston as well causing blowby under pressure only...

Hope you find out your issues. good luck