Today was the first day I could really get on the car, and something surprised me....according to the Defi BF boost gauge, boost is peaking at 0.69-0.7 bar which is roughly 10+ PSI.....From what I noticed (and not positive), under load the boost is peaking at around 0.6 bar (8.5-9 PSI). Not sure if the peak 0.7 is coming after I let off the gas or what...

But either way I thought the base map was tuned somewhere between 6-8 PSI, no?

What are you others getting out of the box? Is the gauge maybe off?

If it matters, I have the APS TT, APS test pipes, and Injen true dual exhaust.

 

surprised your making so much boost with that tiny exhaust... i measured the pipes on the Injen dual and they were 1.9"

the APS setup is tuned for 11-12 psi so I wouldnt worry about it, just get it on a dyno to make sure its all good.

there has apparently been issues with the o-ring on the nipple for the fuel pressure regulator getting torn when inserting it in the gold anodized housing they make for it... the hole it slips into is not very nicely machined or deburred so on a car I put together the o-ring was finely cut into 2 pieces all the wya around and i couldnt get all my pressure and the car was going a tad lean on top... i discovered this problem when an APS dealer I spoke with told me he has seen this problem several times and he was correct on his guess what the problem was.

 

Thanks for the response Charles.

I thought the Injen was supposed to be 2.5"??

I actually wanted to play it safe and run conservatively, since everything boost is controlled by the Unichip, is there anything I can do to bump the max boost down to say 8.5psi?

At the boost it seems that I am making now, should I feel safe with the motor not blowing?

I'm not sure if there any Unichip shops around here that are capable of strapping me on the dyno and tuning...

 

So you think this could be a problem with mine?

I don't have my wideband on yet (just need to install the 02 bung, but everything else is installed and ready to go on that).....so I'm not sure if I'm runnig rich or lean...but I do know there is a lot of black residue on the exhaust, so I'm assuming I'm running pretty rich...?

 

Maybe there is more than one dual Injen? I just know there was one here on a customer car we built and I told him it HAD to go if we were going to hit his goals of a fairly conservative 500+ rwhp.

Unfortunatly to turn down the boost you have to go to a APS dealer, its controled by the unichip... how nice, eh? The other way you can do this is to disconnect their solenoid all together and then it will go down to around 5 psi, and you can use a real boost controller to turn it up to where you want it.

Even if you cannot find someone that can tune it (might want to consider an E-Manage) you still need to get it on a dyno ASAP to make sure everything is OK. The kit is plug and play tuned perfectly, but thats assuming everything went perfect on the installl... which it PROBABLY did, but only one way to know for certain.

 

I am not suggesting that your having any problems at all, but its just somethign I wanted to give you a heads up on. Since it appears to be a fairly common issue, I figured you should know it existed since it is something that could heavily effect if your car is running how APS tuned it to run or not. If all the fuel pressure isnt there, then of course it would not be. Get your wideband gauge installed ASAP!!! any boosted 350z should have one, especially if it hasnt been on or doesnt frequently visit a chassis dyno.

As for the black residue, you definatly dont want to rely on this is your tuning gauge. A turbo 350z on stock engine needs to run extremely rich the second its in boost, beyond that only a wideband can tell you how rich it is. The residue could also been burning oil... i have spoke with several APS kit installers who have had issues with the kit burning oil on heavy engine decel, and i have also experienced this.

 

Ok I'll see what I can do...I believe that Altered Atmosphere can tune unichip....

What should I be looking for on the dyno?

There are actually two version, the straight-tip and the angled-tip. The straight-tip is the second version. It is SUPPOSED to either be 2.25" or 2.5"....do you remember if the tips were angled or straight? The angled version was 1.96" for sure...

 

I'm also having some black smoke on decel....I thought it was maybe the turbos, manifolds or test pipes burning in.

I also have a nice little (big) water leak which appears to be coming from the drivers side steel water pipe where it enters the engine towards the front of the car, from the lower bolt. I can't get in there to really check it because of all the piping, I'm praying there's a way to fix it without ripping out all the piping on the left side of the car.

 

Ive read the APS instructions and its says somthing about filling with too much oil might cause black smoke when decelarating. Also about that nipple leaking this might be a stupid question but will such a leak cause the fuel pressure to drop?

 

Some people claim to not have oil burning issues, some say they have fixed it merely by playing around with the oil return lines. Some said they have had to restrict the oil feed lines to the turbos to get the problem to stop. The car that was doing it to us we had gone down to .040" restrictors and still had the problem, but Garret recommends I believe a .032" orifice to the feeds... so we will try that... we adjusted the return hoses the best we could and that didnt seem to help at all. APS did tell us that regardless of the oil pans extra capacity we should still only put in 5 quarts, which is what i put in turbo Z's running stock oil pans. So we went from 5.5-5.75 quarts down to the 5 and that didnt help either. Regardless of the fact the car had absolutely perfect leakdown and compression numbers, since at the time this happened there were not many people who were speaking up about the problem, I was concerned it was a problem with the engine. Since we couldnt make more than 10 psi of boost on the car that also took away a little of my confidence in the engine I had built as well... turns out that was just the now well known problem of the wastegate actuator springs being too light to hold the manifold backpressure. It actually had me convinced that something must be wrong with the engine, we tore it down and inspected everything and found that it was perfection and everything had broken in mint... somewhat of a big waste of time but it didnt bother me to be able to reinspect what was at the time the first VQ35 we had built after puting about 1000 miles on it. So whatever, I considered it the price of my R&D and ensuring that the product of our engine builds are nothing short of perfect. Ill let you guys know when I have the oil burning on decel fixed. The car is just sitting around collecting dust until we get some actuators to run some real boost. Engine is just sitting on a stand ready to go back in the car after swapping actuators.

As for the fuel pressure thing, basically what was happening was that on the very top end the car was going just a little bit lean, not unsafe, but not where i wanted it. So the APS dealer who had seen the problem a few times suggested that I look into it and sure enough that O-Ring was complete cut into an inner and outter section but the un-deburred and very sharp edge of the oriface... I deburred it and smooth it out and put a new o-ring on. Not sure if problem is solved yet havent had it on the dyno.

 

Hey Dave,
Which map did they ship you installed on the Unichip? I saw about 7lbs on the base 91 map and have since tuned it to 9lbs on 93.... Also, make sure your vaccum lines are routed corectly... If you don't have the lines routed to the boost soleniod correctly, then it isn't controlling boost... We actually disconnected ours on purpose to max out the actuattors(springs) and I see about .70 under load on the street... Also, it is common to see more boost on the street than the dyno....
Jason
"MRC"

 

Hey Jason, long time no talk...thanks for chiming in!

I've been speaking with APS regarding my concerns in the background...basically they are saying that removing the cats increases the boost by about 1-1.5 PSI. On top of that, the better the exhaust system, the higher the boost will be.

I should have the base 91 map. All of the vacuum lines should be correct, everything was double checked multiple times.

I think what I'll be doing now is installing the stock cats until I can get the car tuned with the test pipes...

 

Dave I'm not surprised that the boost pressure is around 10 PSI with test pipes, if you remove the stock cats the boost will increase for sure.


The boost pressure for the APS twin turbo with a good low restriction exhaust system will be approx 8 to 8.5 PSI out of the box.

Regards

Peter

 

Peter,

Would you recommend someone running the APS TT with the out of the box tune to keep their stock cats on if they don't plan on having the kit retuned?

 

According to what I've been talking about with Peter in PM, I believe this is the case. He recommended to me to put the stock cats on until I can get the car tuned with the test pipes.

 

D@ActiveTuning you can contact them directly at http://www.unichip.us/ for locations of dealers/tuners. When I had asked them, they replied quickly.

 

Yeah I know, I'll be doing the tuning most likely at CARV2 in Delaware.

 

Cool. Unfortunately if I buy the APS TT, I am going to be stuck with the stock tune......unless I ship my car 3,000 miles to Cali.

Good luck, keep us posted.

 

Trust me, it's still awesome! While I guess my car has a bit more power than stock tune because of the test pipes, I have taken a ride in Jason's car from MRC Motorsports right after they installed the first kit on the stock tune, and it was purely awesome as well.

 

That would certainly be the best approach for safe engine operation as that is the combination we used when developing the tuning maps fore the APS twin turbo system.

If guys do intend on fitting test pipes to the twin turbo system then at a minimum the air fuel ratio and boost pressure should be data logged to verify safe engine operation.

If there's any question in regard to safe engine operation then the car should tuned by a competent engine/dyno tuner to ensure safe ignition timing, AFR, and boost pressure.

Thanks

Peter