Stillen or gtm supercharger?
 

I am looking into getting a supercharger but cannot make up my mind. Both brands are well respected. Please help me out from your knowledge and experience. Thanks

Oh boy... be ready for the "Use the Search" assault...

I think it is safe to say that the GTM kit is more used and respected HOWEVER a few folks have had great success with the Stillen kit... notably RCZ.

GTM uses the Rotrex kit which, in my opinion, has more potential than the other centrifugal and roots style kits.

There is an interesting read regarding someone who switched from Stillen to GTM floating around and I think their opinions are valuable considering they experienced both.

And one more thing... tuning, tuning, tuning!

If you like a really clean looking engine bay go with the GTM kit. The GTM kit is a proven performer, And with the stage 2 finally becoming available there is really no other kit to look at

Right now the GTM stage 2 SC kit is a really good deal for 500WHP...

You might want to order it before he raises the price.

If I ever feel the need I will upgrade to the stage2 kit.

Search button is ur friend. But go in the forced induction thread.. You will see more gtm them stillen. Interesting I haven't seen stillen on here in a while

Ibtl

GTM seems to get good reviews from everyone...stillen seems to get good reviews mostly from people they sponsor.

What about performance between stillen and gtm stage 2?

err... uhh... why would this be locked..

How long and how much are these installations ?

Because every gtm vs stillen thread turns bad. There's atleast ten of them

i just wish i had half the money i would need for either kit!

If you are interested in making more power, the Stillen kit uses a Vortech supercharger which is capable of flowing more than even the stage 2 Rotrex unit that comes with GTM. However, people have had hit or miss experiences with Stillen kits while everyone with a GTM kit is extremely happy. Most of the praise that the GTM kit receives is the smooth and easy driveability, linear power and torque output, and a very clean install.

I would say that the GTM stage 2 supercharger is the best FI option out there for the Z as it retains linear and instant power delivery which I feel suits the precise and balanced handling of the car. Turbos can't deliver that experience in my opinion.

In regards to the Vortech supercharger's flow capabilities vs. the Rotrex, there was a discussion in this thread: http://www.the370z.com/forced-induct...ailable-5.html regarding that.

The result of that discussion was that while the compressor that the Vortech uses may in fact flow about 2% more air than the Rotrex, the rotating assembly of the Vortech cannot spin fast enough to actually achieve what the compressor is rated at.

About 5 years ago, before we started even developing a supercharger kit, we had a customer with a G35 and a Vortech supercharger kit. As far as I know, we are the only company to achieve over 500whp with the Vortech, and that was using their biggest supercharger (T-Trim). When I say that the rotating assembly just can't handle spinning high rpm, that comes from experience...that supercharger failed 3x trying to push 500whp. When we tried to get the unit warrantied, Vortech came back and said that we were over-spinning the blower...keep in mind that this was on a DE car with a 6500prm redline. The customer finally gave up on the Vortech and went Twin Turbo instead.

The thing about the way the Vortech is rated that people are forgetting is that those blowers were designed specifically for V8 engines with low volumetric efficiency. What this means is that they produce more boost at lower rpm on an inefficient motor. Remember that boost is nothing more than a measurement of restriction. On the VQ motor, the Vortech has to spin higher than it is capable of spinning in order to produce enough boost to make it's rated power.

The Rotrex blower on the other hand was designed specifically for high efficiency engines and is capable of spinning to high rpms with very little parasitic losses. So in essence, you'll never see that extra 2% flow the Vortech is rated at.

I also want to point out that our stage 2 supercharger kit is using a fairly large pulley and isn't even maxed out yet. There was a member who pretty much did every modification under the sun you could possibly do to a Vortech and still doesn't quite make what our Stage 2 kit does out of the box.

There are a few people that have gotten more than 500whp on VQ35DE.Here is one guy with a SC Trim with a 928 impeller built motor.

Vortech tuned with Motordyne XYZ pipe and ART Pipes...interesting results - MY350Z.COM Forums


Here is another build done on a dyno dynamics with a T Trim.This car made a max of 530WHP. http://http://my350z.com/forum/force...ake-power.html

Now I get where you are going when you say Vortech's are designed specifically for V8 engines with low VE.However there are plenty of E90/E92 M3 with kits from ESS and Gintani making well over 500whp.Those motor's are not inefficient low rpm motors,they rev all the way to 8500 Rpm's with Vortech Blowers.

Now as far as the way the GTM kit is designed compared to Stillen's kit :tiphat:to you guys at GTM.You guys Stage 2 looks promising.

Considering that the Stillen Kit does not come with the 928 Impeller or a T-Trim it's comparing apples to oranges.

I was specifically addressing the comment regarding the base Vortech blower in the Stillen kit being bigger than the base C38-91 Rotrex blower in our Stage 2 kit.

In fact, my comparison of the Vortech T-trim we did in this thread: GT Motorsports: 500rwhp/455rwtq Vortech T-Trim, FCon VPro, GTM Built Engine - Page 2 - MY350Z.COM Forums is apples to oranges as well. The main point of me mentioning that particular build was to illustrate that the Vortech simply cannot handle spinning that high for very long. Remember, that car ended up going through 3 blower failures.

As far as the 928 impeller being better, that is an additional cost to the base Stillen kit and causes you to lose the warranty that Stillen offers. Even with the 928 impeller, the graphs speak for themselves:

GTM Stage 2 Supercharger Kit


Here's your graph from your thread.


Please don't take this the wrong way as I really commend you for pushing the envelope with the Stillen setup. :tiphat: Since you are the only person with the 928 impeller on a 370Z, I have couple questions.

1) Do you think it was worth going this route? Would you recommend it to other guys with the Stillen kit?

2) Are you maxed out with your setup or do you think there's more in it? The reason I ask, is I don't know what your impeller speed is at redline. How much more can you spin that blower?

The expansion of power using the SC still requires cracking and tuning VVEL, any progress on that?

Lol don't hold your breath. I think Uprev will crack it first.

Really? Because last time I talked to them they were not interested in working on VVEL.

Having the ability to tune the VVEL and have full control over the ECU will always bring advantages to the table. But at what price will it be worth it?

Let's say for example, we threw a Motec on this engine and had full control over it. Is the cost worth the extra control?

Looking at the dyno graph this is a Picasso. Can more control make it better? That remains to be seen.

As for the VVEL progress, we did run into a little snag with the hardware we are using. Our intention was to be very cost conscious of the system we offer. Unfortunately, the company that was supplying the hardware folded up shop so we are working on Plan B.

Plan B involves a lot more than just a VVEL controller. Long term, we will be developing a universal full standalone EMS option similar to the HKS FCon V-Pro. A system like that does require a lot of time to develop so please be patient while we get this going.

As far as Uprev working on VVEL control, I really hope they do because it would be the most affordable option. However, like theDreamer said, they aren't interested in working on it at this point.

Figure, with the stage 2 you're probably at the stock block's safe limits as it is. You're probably going to want to build the block before exceeding the aforementioned posted results, thus you're probably going to run a stand alone like the F-Con anyway. How does the F-Con match up with VVEL right now? Does it allow for additional tuning capabilities?

For long term reliability, I'd say the Stage 2 is right where you want it to be as it is.

The F-Con has no control over VVEL.

@OP - buy my Stillen SC so i can buy a GTM TT. :tup:

I heard the F-Con isn't as advanced as our ECUs are and I was told to stay away from it.

Ok to answer your questions

1.I dont think it was worth it because the piston in cylinder #2 took a dump on me I am building my motor now. All other were fine showed no signs of detonation in any other cylinder. Also the price and out the box performance is another reason, my kit was used thats the only reason I have it now.

2.No I am not maxed out my impeller speed is 56000 rpms at red line. I can go to 60k with the impeller, the ABEC 7 bearings in the unit are rated to 59k. What may limit me is the design like it did on my first set up.

My first set up had issue's my MAF's maxed out way before red line 6700 rpm's. My boost was all over the place I know this killed my power.

Take a look at the boost log from my dyno graph as a example. As you can see it's up and down,had it been leiner without dips and maxed out maf's. I have no doubt that it would have made way more power.



http://img843.imageshack.us/img843/8476/dyno1.jpg


http://img841.imageshack.us/img841/9709/dyno2.jpg


The reason I made my first post in response to what you said about the blower.




For another apples to oranges comparison here is a Gintani the S65 engine has a very high volumetric efficiency.This proves that you can make power on a engine with high VE,what is holding th Stillen kit back is design.

Vortech. Gintani Stage 2+ "New" Dyno Results... - BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3)

Also Mike when you say the blower failed 3 times what failed impeller bearing? Because on a DE non rev-up with 6600 redline your not over spinning a T Trim with a 2.87 pulley.


With the volumetric efficiency of this engine it would make a way more power with larger
displacement. The 3.7 would do wonders if it was strong the same can be said for the DE.

At that point though better of going with a set of Turbo's witch is what i plan to do once I max this set up out.

First off, I'm very sorry to hear about your motor. Odd that it was only cylinder number 2 that failed. Any theories as to why?

As far as the blower failure, yes, it was the bearings. We didn't think we were overspinning it either and our math showed that. However, Vortech was adamant that we were overspinning it and refused the warranty (the blower wasn't even 3 months old at the last failure). The biggest problem was that it was a V-2 unit and of course when it took a crap, it took the motor with it. When Vortech denied the warranty, the customer was done and washed his hands of the whole supercharger business and went with our Twin Turbo system that he is enjoying to this day.

I wish you luck with your build!

One of injector's for that faild a flow test, the day my motor started smoking I got a misfire code.After looking at some log's with uprev and doing to calulations. I dont like where my duty cycle is so I am going with a bigger set this time around.As the days went the car started smoking more and ,we yanked the motor out in about 5-6 hours.The engine is being assembled now took forever to get all the parts.I am tempted to do a Turbo set up now but I am curios to see the end result.

I remember a while back Vortech had a bunch of bad blower's that was going around that sucks for the customers car you worked on.

Wow that's crazy

interesting...

We are currently working on support for VHR cams

fingers crossed, champagne shall pour from the heavens the day someone has a cost effective crack to VVEL

I'm glad to be wrong, I did not know that . Uprev will be the most cost effective option hands down .

Sam

Not many threads on their forum, but hopefully that will change with time.

can someone please explain why cracking the VVEL is important, and what does it do. Sorry for the noob question ive just been reading a lot of FI threads lately and VVEL is brought up in all of them.

I'll take a shot at this, and I might be off. Right now tuners aren't able to control the vvel, this you know. VVEL is simaliar to cam phasing. So currently tuners are adjusting timing, ignition, and fuel. Possibly others. But since they cant adjust the VVEL people are believeing were possibly getting blow through. So the way I see it is lets say me being FI i am running 7 psi but in all reality my car is only seeing 5 psi because the other 2 psi is just being blown through and out the valves. If they can control this they can leave the valves open or clased longer there can be more power to be made. Now there comes risk though. Alot of the tuners didnt want anything to do with this because they felt that the risk is way more then the benefit. risk being by controling the valves we can bend one and damage pistons, and they didn't want to be held liable for the damages. Another conpany just gave up on trying to crack it after alot of people bought there access port. Here recently sam anounced he is trying to crack. I don't know where he is at with it or if he already got control of it through the F-CON and is trying to make a smaller cheaper component that we can buy instead of a whole F-CON. Also as far as I knew SAM was the only one working on this. I remember uprev saying they weren't getting into this because the cost is greater then the benefit, but apperantly they changed there mind because they said they were working it. Most likely they are persueing it because sam showed there was a market for it and that it could be done. I don't know if I explained everything right but I am pretty sure I got the main parts off it. If I have anything wrong these guys will jump in and correct me

That was really helpful toner, thanks