SC Install resulted in 50 more HP...suggestions needed
 

Past summer drove a friends 5.0 Mustang with an after market super charger and it was raw power. After that I was determined to get an SC for my Z.
So in the fall I bought a Stillen super charger, oil cooler, and PLX boost gauge. Finally finished the install with my mechanic and got some drive time.
The results were not the raw power like the Mustang but I was told that was due to large displacement of american. Anyway, I don't know what I should expect as I don't know what 400 hp in a Z SHOULD feel like.
I last week I put it on the road in 3rd gear and took it up to almost 7k RPM and boost gauge read around 7.4...so I think it would be pretty close to Stillen's 7.8 to 8.4 boost at 7k RPM.
So yesterday I took it to a dyno to get an official HP/Torque measurement. The guy did 1st pull in 4th (albeit 5th is 1:1) with a load of 10%...result was 337 HP / 286.4 Torque and the dash boost gauge only read around 5.8. So he tried different load, tried different gear, etc. Here are the results:
Run 1: Gear=4, Load=10%, HP=337, TQ=286.4, Boost read ~6.3
Run 2: Gear=4, Load=7%, HP=336.9, TQ=284.6, Boost read ~5.8
Run 3: Gear=5, Load=5%, HP=328.8, TQ=273.1, Boost read ~5.5
Run 4: Gear=3, Load=5%, HP=327.1, TQ=274.3, Boost read ~6.1
Dyno guy said something was not right and didn't think the super charger was really spinning up. He mentioned a smoke test.

That night after getting depressed about the dyno, I decided to try it out on the street again in 3rd gear up to 7k...and I read 7.6 on the boost gauge. So twice running on the street it seemed to get pretty close to Stillens boost range, but not on the dyno...and since I don't really know what to expect I don't know what is right and what is wrong.

So today I called Stillen, they said it might have a Boost leak too. I talked to the mechanic and he said if it had a leak you would hear it leaking air and idle wouldn't be correct...but idle is correct and I don't hear any leaks.

I did use cypher to get successful data logs for two of the runs, I also grabbed a data log from my street test that night. i looked through the data but I don't really know what I can look for.

I would appreciate if anyone would like to provide helpful commentary.
Thanks for your help in advance,
/Z/

Have you checked out this thread? http://www.the370z.com/forced-induct...r-upgrade.html

Stillen is OK for what it does, but there have been many discussions here about its shortcomings -- the main one being the flow restriction and poor heat exchange of the supplied intercooler.

If I understand correctly, even if you don't increase boost, you'll notice substantial improvement by going A2A.

In addition, Stillen's tune is apparently terrible. A better tune would most likely give you higher numbers.

Silly question, but has this been properly tuned or are you using the tune that came from Stillen with the kit?

Ditch the canned Stillen tune. Ecutek if that's feasible.

Beyond there there are many ways to improve on the shortcomings of the Stillen setup. Spend some time reading through the forced induction thread and builds.

All that said, you are still well below Stillen's 400+ claims. What kind of dyno was it? That's too far off to just dismiss as a low reading dyno though, something has to be up. I didn't use much more than the manifold, blower and coolant pump from the Stillen kit so can't help diagnose the other bits too much.

Really wondering if you were expecting the same power of a SC 5.0 V8 out of your SC 3.7 v6... If that is the case you need to learn a lot more things...
That aside It definitely seems like you could Definitely be making more power...

Can you provide the details as to who did the install of the super charger . Did the shop know what they were doing etc. What tune?

@bcfromfl...yes i read that thread and look like a future addition, but I want to make sure the curren t set up is working as expected before i add more unknowns to the equation.

@MoulaZ...I paid for the canned tune, but accordin to the dyno I have 50 out of the 110 to 120 HP they say i should get with the canned tune.

@ChaseZ...not sure the type of dyno, i could fi nd out but i dyno'd the car just before install on same dyno and same guy and it showed 290whp which is right in line with Nismo numbers. It is way too low, I agree something is up. Just not sure how to tell if it was bad dyno, install issue, or tune issue.

@king...honestly, i was expecting to feel more, especially given a smaller car compared to a stang...but i know larger displacment engines produce different effects...i just never had the opportunity to witness the two differences given equivalent hp numbers.

Heck I'm not saying the tune isnt right or the install has problems because i did see the boost gauge hit 7.6 on the road...but the dyno pulls didnt give expected results nn d dont know why. I could oo another dyno run somewhere else for another $180 or a smoke test for ?. I looked through data and i can tell when i go wot...i can see my afr values at 10 the whole time from 2500 to 7000 rpm...among other data items, but i dont know if those numbers are appropriate and what else I can determine from all the logged data. Was hoping to come to conclusion of do another dyno or do smoke test based on numbers. What can I check?

Anyway, thanks for you concern and comments.

@Presto...install was done by a 30yr certified mechanic from family business. Used them for 30 yrs myself, he has great knowledge and is very meticulous. Albeit, he told me he never installed an after market super charger but he has worked on factory turbo and super charger vehicles. Actually, he and I did the install together...well I read the manual and watched over his shoulder as a set of second eyes. He would allow me to do some things and when I was done he would inspect my work. It was much like a mentor/student...and then a beer to 3 after we called it a day :-)
Honestly, the manual along eith his knowledge and tools...the install went extremely well. Hardest two parts were lowering and positioning of the heavy SC into place with that boot...and getting the charge pipe in all three connector places at the same time.

You need a custom tune. The stillen kit is critically flawed, but you can get a safer, more powerful setup with a custom tune until you can ditch the garbage intercooler setup sometime down the line.

It doesn't feel like the sc mustang since that's most likely a positive displacement blower, and the stillen is a centrifugal.

I agree with Chuck and others...get rid of the canned tune it will just cause problems.
Also, the 110-120 "they" say you should get, is this coming from Stillen themselves? No offense but do not trust the ad they throw around, also their final numbers are under perfect dyno conditions. This means no heat soak on the tiny heat extractor OR water, properly tuned for your car, and running in cool weather with zero humidity.

From reading various threads...should i be able to get an idea of boost by looking at MAP from Cypher data log?

Unfortunately no, OBD2 out of our cars were never wired for boost since from factory we are a NA car. You will either need to run an independent gauge for this, along with for AFR which I highly suggest also.

@chuck yes mustang was a wipple sc...i was an awsome throw back! But I am a z-man ;-)

@dreamer Yes, guy from Stillen said that his tune will delive the 402 to 420 HP. He was absolutely confident of that. I dont know what the humidity was on wednesday morning but im on east coast and outside temp was in mid 40s and my oil temp was started at 190 and ended at 217...nice temps and the cool outside temp should have made nice numbers.
I will change tunes in the future when i go with a2a and drop the cats...but for nowI need to make sure it is running as designed.

The cypher data log shows me AFR. How is it getting that number...it looks reasonable i think...well at least it is changing, it isnt garbage numbers, and seems to make sense with respect to lean and rich conditions.

Did you ever do a perform SC dyno run, you cannot take the 402-420HP from their results as a comparison, you would need to compare your pre-SC dyno to post-SC dyno. For example, my true original dyno run when my car was 100% stock was 240HP versus others getting 260-270HP, I went to a dyno that read super low.

Contact Sbastian at Specialty Z in Chatsworth in Ca
Stillen claimed my car was at 419 but also like you my car felt flat
after Seb did a custom Air 2 air set up and ECUTek tune the car feels good

Uprev pulls AFR but I remember a forum member stating it was not 100% representative of what the actual AFR is, it is close but the best way to know your AFR is to run directly to it.

yes, a pre install dyno was done on same machin with same operator. Three pulls averaged to 290 HP on my stock nismo. So my post install gave me a delta of ~47 HP. I plan on doing dyno after each upgrade.

The statements about hearing and feeling a boost leak is incorrect. I couldnt hear or feel a thing when I was installing my kit but knew something was off. I pressurized my system and found a bad leak at only 3psi from the MAF sensor, the gasket was crimped.

As others have said, its that garbage stillen tune. This is their ultra safe tune that they use for warranty purposes. Getting a custom tune will make the car a whole lot better (pending no boost leak).

Have you confirmed the water system is operating properly? There are numerous guys here that have had the pump not hooked up or something and then you are basically blowing such hot air that it is robbing you of a lot of power. Just something else to consider.

When you get that all figured out and make some decent power...let me know when you are ready to make some big power and Ill get you the Air to Air. It will also help with that "throw back" feeling as it increasing responsiveness 10 fold.

Do you have any of the graphs available that you can post so we can see how far he took the car each time?
With the Stillen being centrifugal it does not make max boost until redline (7500), and I have seen even with my own car they did not take it to redline and it looked off until I realized they only went to 6800-7200.

@topgunz...thanks for the info about not hearing leaks! As far as the water system, I believe it is working properly. We had a little trouble getting the pump started as it was air locked, but was quickly corrected (with a little bit of a mess). The whole install took a while as we worked on it sporadically over time when we both could get together. Took so long the battery died and we had to jump the car for it's first fire up after the install (first turn after install and it doesn't turn over scared the crap out of me...in the back of my head I heard my wife telling me I wasted my...our...money). So when we jumped the car it blew the 4A fuse of the pump. Mechanic noticed it wasn't running so we shut it down and found the blown fuse.
I now periodically check the reservoir. The reservoir has quite the turbulence and I often listen for pump running prior to starting the car.
I will look you up for the A2A!

@dreamer...tonight I will try to get you the data. I will chop out the parts that are just leading up to the pulls and the parts that are after throttle is let out. I do a quick check and you are right about the MAP...at 2500RPM is is at 3.02 and when WOT start and RPMs start to ramp up it slowly starts increasing and by around 3500 it is at 4.88 and stays there up through 6800 RPM and doens't go any higher...Im guess it is at the max voltage by then and goes with what your saying that I need an after market sensor that has a higher dynamic range. I assume previously it only needed to measure "negative" pressure and now it needs to measure both "negative" and "positive" pressures.

I do have a boost sensor but I didn't log that data as the gauge supposedly does the logging and didnt figure out how to do that. Just getting the Cypher to log was my main task while dyno'ing. Didn't want to hold up the operator to figure out how to log using the gauge (PLX).

I think these guys are onto something ...

:rolleyes: I think you have just experienced exactly how 'good' the Stillen canned tune is :ugh2:

Seb with Specialty Z gets rave reviews for remote tuning - he's an extremely experienced tuner with excellent customer service and response time :twocents:

I don't have any personal experience with the stillen kit - but something is definitely wrong here outside of the poor stillen tune solution. He really should be making a lot more than +50whp.

There very well could be something wrong, but he wouldn't be the first guy to make far less than stillen claims for power. The really sad thing is, even though the tune is conservative and makes no power, it's still not particularly safe when compared to a custom tune.

I know one guy here in Texas who got a 62 hp increase at the dyno over stock using the canned Stillen tune. Custom tune was more than double that. FWIW.

From all that I've read and heard, the Stillen canned tune is barely sufficient to drive to a nearby tuner for a custom tune :eekdance:

But hey - it's CARB legal =)

AND you get a 36K warranty...but at cheap breathing mod power levels.

With Stillen tune my car did 320 , after Seb im at 420 at the wheels

That does seem pretty definitive.

You have an air to air conversion and are only at 420whp? Dont get me wrong, gaining 100whp is nice from that plus tune but why so low? Did you just want safety?

We call Vortech and asked about the smaller pulley for more boost and they didnt recommend it as they said Stillen supercharger is pretty much at the max RPM they recommend , also its on crap Ca 91 octane

I was thinking about doing the exchange plan Vortech has but i dont know how much longer im gonna keep the car

So to answer the question , yes safety

Yeah, they didn't design it to take more heat than the 8psi so I can see that. You can get the9psi from concept z for half the price anyway fyi.

Got a link or part number?

Also will it need a tensioner or how does it cover the belt slack ?

conceptzperformance.com/stillen-407737-13-supercharger-system-pulley-9lb-nissan-370z-09

It doesn't "need" an extra tensioner. However, there will be some belt slip in higher range. Nothing terrible but you can eliminate it and pick up an extra psi from adding the extra pulley. See mod in my thread starting around page 66 or something.

Ok sorry it took so long to post my data, but was busy with family events. Anyway, after extensive searching of information on the internet and some quick post-processing and comparing my "Street" run and the "Dyno" runs I believe the issue is the Dyno operator didn't load the rollers with enough resistance to allow the SC to kick in to it's full potential.

Can someone confirm or second my hypothesis?

Attached you should find links to a street run and a dyno run along with some pics of the post-processing and data comparisons. A few words about the data...
- All the "Dyno" runs showed the same trends and characteristics among them, so which one I used to compare is irrelevant.
- The one "Dyno" run was on a 0-60 log so it stopped logging around 63mph
- I removed data before the starting (2500rpm) and after letting off WOT.
- The data is not my post-processed, so it's raw dump values.

Pic Info:
- I post-processed data so all the graphs, the X-AXIS IS RPM...not sample! So all graphs data element is function of RPM.
- The graph titles tell you the Cypher data elements, the graph legend will tell you which color is street and which is dyno.
- The side-by-side AFR and Base Fuel Schd plots are comparing Street vs Dyno within each graph and comparing the two side-by-side graphs shows consistency among different (bad) Dyno runs.
- The pic of four shows various data elements comparisons of Street vs Dyno.

https://drive.google.com/open?id=0B1...zltQnVaRDBmRm8
https://drive.google.com/open?id=0B1...EtzMzFtYkp4cU0
https://drive.google.com/open?id=0B1...E0yT195WkhCWHc

Ugg...forgot how to get pics in...and my attached files didn't seem to show up anywhere...trying again...

Pics:
https://drive.google.com/open?id=0B1...zltQnVaRDBmRm8
https://drive.google.com/open?id=0B1...EtzMzFtYkp4cU0
https://drive.google.com/open?id=0B1...E0yT195WkhCWHc

Data Files (csv):
https://drive.google.com/open?id=0B1...UJqTmRKUlQ1M3M
https://drive.google.com/open?id=0B1...XdRUUNIZkc0aFE

Does anyone with dyno experience know what happens if a SC car is run without tension on the dyno pulleys? How much tension is necessary for SC'd pulls? Does anyone know what cpuld cause the graphs to produce drastically different response? e.g. AFR delays to increase and doesnt increase as high.

/Z/

Any belt slip, clutch slip, that sort of thing?

An eddy current dyno should balance the load automatically so that itself shouldn't be an issue.

No clutch slip, but I'm not sure what SC belt slip feels like. I did not change the SC belt tension as stillen ships it tensioned appropriately. I checked the tension of the SC belt and it seems faily taught.