Hi guys and gals,

I have been a member here for a while, however I did not post much, I was mostly "lurking" in the last year or so. I see quite a few posts asking about turbo and SC kits and the differences, so I thought I'd pop in my 2c...

I have an 03 Enthusiast Z (blue) which I purchased with intention of modifying it (esp when I realized it was not all that fast stock :-) at least for my taste). I've so far experienced Stillen SC on the car, and I am now running a Greddy TT.

Before I get into details with regards to my feel on these two kits, I want to mention that my goal was not to be the best, strongest, biggest, and baddest ***** out there. I just wanted to have a relatively fast daily driver, with good HP and torque all over.

That said, obviously when I got the car, I did some research based on dyno charts of people that had installed aftermarket F/I kits (at the time there were only Stillen, ATI, Vortech, Greddy, and APS, if I recall). My conclusion, after doing the research, was that Stillen was the most gratifying daily driver of them all and had the potential to deliver the power gains I was looking for.

However, I made few mistakes in my selection at that time:
* I did not consider how my other modifications (intake, exhaust, etc.) would affect my chosen kit.
* I did investigate problems with the kit, but I did not actively ask in forums (I mainly looked for others complaining, if any).
* I did not consider the changes to weight distribution in my car, and how it would affect my overall driving experience.
* I did not check if the installing shop was comfortable with installing this kit (it was still relatively new at the time).
* I did not consider the kit's performance in local weather conditions (namely, in Houston heat for most of the year).

 

(continued)

Onto Stillen SC...

Overall, I purchased Stillen stage 2 kit, their warranty, and few other components...
* Blitz LM radiator (there was no Koyo at the time)
* Borla TD exhaust
* RT cats
* AEM intake
* SAFC2 airflow controller
* Greddy boost and A/F gauges
...and had them all installed at SGP Racing.

Things to note:
- Greddy gauges measure in metric values, keep that in mind.
- AEM intake uses aluminum tube, with no insulation from engine (and SC) heat. Insulate it, if you can, with some heat wrap or similar.
- Borla TD is composed of many little parts, and is fairly difficult to get simmetrically correct. Also, after a while, mine developed creaking sounds which are still present on the car.
- Water wetter added to engine coolant tends to build up solids. Probably not good, I discontinued using it.

We took the car to dyno... and it dynoed about 250-260whp, and around 245wtq.



SGP could not figure out the problem as to why the car was not making 300ish whp, as advertised. My baseline dyno was 230whp/230wtq, so there obviously was an issue. After some tuning, they got me to 267whp and we called it a day.

What followed was several months on phone with Stillen, which can be summed up as:
* pulling teeth to fulfill warranty I purchased
* them (Stillen) finding that my SC blower was "seizing" and sending me a new one
* them (Stillen) sending me 3 (three) SC belts (the small ones on top) until last one stopped slipping
* me, getting upset with SGP for not being able to give me an answer and taking the car to Lightspeed to get a second opinion
* Tom and I @ Lightspeed, finding out that alternator belt was slipping too and was also causing power loss and belt dust clogging the alternator and causing some major slipping noises
* Tom and I @ Lightspeed, finding out that installing the Stillen-recommended "shim" did not do squat
* me, finding out that RT cats reduce boost from this kit
* me, finding out that open intakes (AEM, Pop charger, etc.) make this car sound like a moving siren -- !!go with K&N filter in stock airbox!!
* me, finding out just how small the intercooler core of this kit is -- VERY very very small and thin, and not really something I think would help cool the intake air if outside temperature climbs to over 85
* me, finding out that there is no way to properly tune timing, etc., on this kit, since it is blackbox design (SAFC2 did help a bit tho)
* many other small thingamajigs...

Ultimately, best I got Stillen to work was in winter, with new belt. We dynoed 300whp and 281wtq (which lasted about a week) and here are my impressions with those numbers only...

Car felt good in low RPMs, torquey. You wanted to accelerate with this car, and it was stock quiet (with stock airbox for intake only!) doing so. As the car approached redline, it was very much same feel as stock, as far as power delivery, but stronger -- e.g., it would taper off towards redline, same way stock would. There was, however, a sizeable jump in torque in midrange and low. My butt dyno felt as though I was driving a V8, but even more jumpy. My MPG suffered only a few miles less. There was less power in hot weather, and even less with A/C on. Having a hot day and A/C on, in other words, meant you'd notice a significant power drop. Additionally, the weight of the SC up front kept my rear end slipping even at mild throttle applications on corners. This was not only due to more torque -- it was also due to weight ditribution changes, with more weight up front (about 80lbs). Car felt front-heavy, and hard cornering, even with no throttle, felt like it was a rainy day, and slippery.

Overall impression (subjective): excellent daily driver, not good for too much heat, BEWARE of problems with belts, drive this type of kit if you like torquey cars, as opposed to 'zingers' , BEWARE of your weight distribution when cornering (learn it, don't lose control!), and this kit is also not the kind you can easily tack on more HP to... it does not respond well to most mid-exhaust modifications (headers, cats), nor open intakes. Lastly, there is no plenum, so depend on Stillen's design to deliver even power to all 6 cylinders. Seeing their intercooler core piece, I'm not sure I believe in their R&D anymore.

After about a year and a half of problems with Stillen (I even installed a custom 8psi pulley, to no avail) I removed the kit and drove the car for several months N/A, to make sure there were no belt (or other) issues stock, before I'd proceed with Turbo installation.

Short on N/A...

N/A, after F/I, feels anemic, let me tell ya . You're wondering, for a while, where's the clog hehe. It feels like engine is bogged down and torqueless, when in fact it is running fine.

 

(continued)

Oh well, onto Greddy TT...

So, to install a turbo, my initial selection was APS TT, due to the completeness of the kit. I also went back to SGP, since I started seeing them more and more as turbo experts, and I believe they tried their best on my Stillen kit but, at the time (2004), in my opinion, did not have enough experience with it to fully troubleshoot it. In fact, if you go to them and ask Mark whether you should go with Stillen or Greddy/APS, I'm fairly certain he'll tell you not to go with Stillen, and may describe the problems I've had as a reference .

When I came to Mark for the turbo kit this time, I asked him what he thought was the best choice and I mentioned my selections so far. He pointed out that Greddy, with few additions, is just as complete as APS, and he also recommended FCON engine management, as opposed to what Greddy/APS came with.

I went along with their suggestions, and made emphasis on the daily driveability of the car, the fact that I'm not looking for huge numbers, and that I'm most concerned with good tuning and solid build, so I avoid problems I had in the past. We also agreed to install my RT cats, additional water temp gauge, plenum spacer, and JWT clutch/flywheel combo. I also noted that there is no longer foam at my front bumper, so I have to be careful now when parking, not to bump into things.

Here is my impression of the turbo...

First of all, Greddy is much (MUCH much!) louder than Stillen. Not in daily driving, but when you press the pedal and get to over 4500rpm, it gets very loud. However, my opinion may be skewed, since SGP installed custom wastegate exhaust short pipes (which I don't understand much) to route exhaust from wastegate, instead of towards the back (apparently, on default greddy install, it goes back into exhaust system, I could be wrong). Again, I don't understand this setup, but it is quite loud. I may revert to stock greddy setup if I don't like it in a few months of driving.

Turbo feels less torquey in lower RPMs, but it is not too much less... as soon as you hit 2500-3000rpm, you start feeling almost the same pull as Stillen. Now, mind you... I'm comparing Greddy TT that dynoed at 400whp to Stillen SC that dynoed at 300whp. That said, difference seems minimal at 2500-3000 range. Below it, Stillen feels nice 1500-2500rpm, but at that range stock N/A feels ok too, and so does Greddy (just like stock). Overall, in low and mid range, turbo does not lag as much as some think it does. At least, not Greddy TT.

However, after you're past about 3500-4000rpm, Stillen will start evening out, whereas Greddy goes nuts. Some may like this, others may not, but the fact is that Turbo just goes nuts after about 4000-4500rpm. Last part of your tach in lower gears is a moment. You have to be careful and fast not to bounce off redline. With Stillen, you got plenty of time to react.

As an example, driving on dry pavement and WOT-ing in 2nd at 4500rpm with Stillen would produce some nice acceleration. Doing the same with Greddy would make my car slip sideways, like on ice. Drift, anyone?

Turbo also "growls" when it starts opening up, even moreso than your exhaust will growl. If you liken stock Z exhaust to a soprano vrooom, and Borla to a tenor/base vrooom, what this turbo adds is a growl that turns into a roar, in addition to the exhaust note. It is as though something starts growling and slowly opens its mouth for more of a "roar" feel, as you're reaching redline. At the same time, driving off boost keeps the car nice and stock quiet (well, stock + Borla quiet, actually ).

My MPG with Stillen suffered more in daily driving then the turbo. This is due to the fact daily driving for me is off boost, or with minimal boost. Very few spurts of acceleration, due to traffic congestion on commute and no space to accelerate. Also, no willingness to be loud and invoke interest of police from half a mile away .

I'll also note that JWT clutch/flywheel combo feels very close to stock, with exception that it catches slightly more abruptly and it is quite opposite of stock clutch + Stillen, which actually kept engine pulling even from low RPMs. With my new combo, I can kill the engine if I'm not thinking when starting. It is, therefore, a bit harder to launch nice and slow, but nothing significant. Pedal pressure feels slightly more, but not more than 10-20% gain in pressure, IMHO. I only notice it in stop and go traffic, as my legs gets a bit more tired after an hour of it .

With turbo recently broken in, this is all I have for now. No problems yet and hopefully none in the future (knock on wood). I hope my description helps some of you, when deciding what to get.

Cheers and best of luck!
-Stan

 

thtas alot of power you are putting out with just 6.5 PSI.. must be the supporting mods

 

I'm guessing those would be the custom setup by Mark (which, if I understood, alleviates backpressure when WOT-ing), as well as clutch change, plenum spacer, etc. Overall, my dyno shows about 375wtq and around 380whp until very last 600-700rpm (so, just about 6K and up) when it jumps last 20-25whp. So, effective whp (or, what I can use mostly) seems 380ish.

 

thanks for the write up.. good read.. I've considered stillen til I've read about all the unhappy people about their service and product.

 

thanks for posting your story

What the stillen kit primarily improves is the tq below 4000 rpms. It makes some power up high, but not anything huge

adding HF cats WILL reduce boost, but increase power. SC's are not constantly presurized by a wastegate like on a turbo. There's a finite amount of boost. If you make it easier to flow out, the pressure will go down, but the power will increase because you're increasing the speed of air flowing out the exhaust

 

Indeed, but this can be deceptive. My experience was that the reduction of boost robbed me of any possible power increases from more exhaust flow.

E.g., I may have gained 10hp from exhaust modifications, but I lost 20hp from losing a pound of boost, thus giving me a net -10hp. These are not my real gains/loses, they're just for illustration purposes, as to what I've experienced.

 

dyno sheet?

nice writeup

 

thanks for the great write up

 

Stan, I appreciate your unbiased opinion of these two set-ups. I'm like you, I do a lot of reading, but not too much posting. I don't ask a lot of questions, so it's nice to read a post that actually addresses everyday concerns when going FI. I'm seriously thinking of the Greddy TT setup in the future. My only problem is, I've never even ridden in a 350Z that's TT so I have no idea what's like. Maybe we can meet up for a beer sometime..

Ross

 

hopefully you take that ride before you have that beer

 

Ha, good idea!

 

Since some wanted to see dyno sheets, here are all three... Baseline from when car was new, my best SC dyno, and now my latest TT dyno. As my disclaimer below says, don't compare numbers so much as curvature of torque and HP curves. I think relative comparison should be so-so ok .

BIG DISCLAIMER: These are just numbers from several DIFFERENT dyno machines. Don't compare them, although we tried to keep conditions similar, numbers mean very little unless done on same machine, with same operator, and with same conditions replicated.

 

Good read!

 

Sure Ross, we can do that. Send me a PM, we'll have to wait few weeks, mainly because I'm sick with cold at this time, and I don't want to give virii to people, and also because I'm about to install whole new stereo in the car (start of next week). So, my best time may be weekend of 20-21st, weather permitting. In any case, PM me and we can set it up.

Forewarning: I'm a granny driver, I push it a bit here and there, so you'll get the feel of it, but I'm nowhere near accustomed to it as some on these forums . Hence, I tend to go towards caution, until I learn the powerband.

 

I had the same problems with breathing mods on a Gcoupe that I installed the stage 2 stillen on. I did I,H,E and the stage 2 kit and he made 263whp. The stillen kit is great for off the line fun. But not so great for high numbers

 

right, Stillen is always saying not to go nuts with a flowing exhaust with their SC, so it makes sense what you say when I think about it


great descriptions BTW. Few people have had the opportunity to actually drive different FI setups for extended periods of time and then write about it - or write as nice of a description as you did. I like the greddy kit, no BS power and sounds mean as hell

was the greddy dyno done on a Dyna-Pak dyno?

 

Glad to see you are finally making the power you wanted Stan. That Stillen SC was a huge nightmare.

 

Thanks for sharing your experience, nice write-up. Enjoy TT.