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

imazman

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/

bcfromfl

Have you checked out this thread? Topgunz - air to air upgrade

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.

MoulaZ

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

ChaseZ

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.

King

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...

Presto

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?

imazman

@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.

imazman

@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.

Chuck33079

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.

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theDreamer

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.

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imazman

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

theDreamer

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.

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imazman

@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.

imazman

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.

theDreamer

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.

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