ttrank, I was just noting when the vortech kicks in not when it reaches full boost as I explained that later. Torque is relative to driving habits, I travel 140 miles a day in my car and thus not having all the boost is good for gas milage, I still get 21.4 and that is with mixed driving.

340rwhp was a number I just picked it was not what I get nor what maybe you get just an example. I don't drag race, not sure why I have never been but one day maybe one day I will.

Well I just want to say that I am glad this did not turn into a bashing thread like others I have witnessed, like I have stated, each system is good for different people.

I hope this helped the poster in some way.
P.

 

with stillen backpressure is desireable... i spoke with stillen and they tell me their td exhaust will yield more power.... but having td will take away the backpressure.... does anyone know for sure whether having td is better then non td.....?

 

I can tell you , with a Vortech . An open exhaust will yield less boost , but more power , Probably a tad bit less trq. down low . I never really compared the trq . , probably because it wasnt much for me to take notice

 

I agree with everything you said except for this. Torque is very relative to driving habits. Anyone that has ever driven a honda knows that. You need torque to get you off the line and up to speed or to get that quick push when you are trying to go from 60-100. HP alone will not do it. The HP is what keeps you there. Otherwise no one would care about how much torque an engine makes.
The honda 1.6 and 1.8L VTEC engines have lots of HP but no TQ down low and they are just crap until high rpm's. You need to drive them like you are on the track all the time to stay in the powerband.
VW figured that out a long time ago and that is why all the 1.8T and 2.8T's make full torque at ~2000rpm and stay flat from there.

 

From everything I have seen on all G's the better tuned and high-flowing your exhaust is the better it performs. If you went with a larger dual and the Stillen S/C you might run into problems but no one has seen issues with the Stillen or Borla exhausts. The other FI kits seem to like as much flow as possible since their boost is not as dependent on backpressure. I think the Stillen flows a tiny bit better but it is a little louder and raspier. That is not my opinion, I have the Borla and have done a side-by-side comparison (Sedan) and everyone agreed, the Stillen looks better, the Borla looks almost stock but sounds like a dream.

The exhaust helps both types because your manifolds and cats are creating most of the back pressure. When I got my kit the first thing Stillen did was told me to get an exhaust even if it wasn't theirs (but they did tell me theirs was the best like I was expecting )

Headers and high-flow cats will reduce back pressure and thus lower boost on the Stillen. Some people have said that Stillen has told them to get their headers with the Stage 3 but they would not tell me the same. I am ok for now but when I go up to Stage 4 I might try high-flow cats and headers. Even if it does not make any more power than the Stage 4 maybe the additional flow would make up for the loss in boost and thus be safer and easier on the engine since it is less boost...

 

Urban, Ttrank, all of this has helped. I want to thank everyone that has thrown out their opinions and facts. That was what I was looking for.

 

Urban; thanks for the info. I like the fact that everyone on these forums are able to discuss things in a civil manner. In the end it all comes down to which kit you'll be happy with! Coming from a turbocharged vehicle though I really hated the lag. Maybe a nice TT setup would change my opinion.

 

You should have a ride in my Mitsu VR4 TT, it only has 620hp crank and 500AWHP

 

Hold on. Before everyone leaves this thread happy and more knowledgeable, many people seemed to agree to the statement quoted here. But, backpressure is never desireable. You will always get more power with no exhaust than with any kind of exhaust. Don't get me wrong here. a poorly designed higher flowing (see larger diameter) exhaust can actually decrease performance, but that's not to say that having backpressure is ever wanted. The lower your backpressure, the more efficient your exhaust stroke is and therefore the more oxygen you bring into the cylinder on the intake stroke. Just wanted to clarify before anyone took that statement as true.

It's an often misunderstood subject from what I've seen on several boards. So, to answer your question luong, it depends on the tune of the exhaust and how much flow you are pushing through it. A higher flowing exhaust (whether it be td or just larger pipes) will need more air pushed through it in order to be effective. For one set volume of air flowing through, a larger exhaust will cool the air faster than a smaller one, thus making it more dense and slowing it. However, with a higher performance car (such as FI), you are pushing a higher volume of air through per stroke and thus need a freer flowing exhaust in order the clear the exhaust in the same amount of time. So, I can't say which is better for you, but since Stillen designed both components, I would tend to listen to their advice as to when the td would be beneficial for you. Hopefully I conveyed that clearly, but if not you can ask me or look it up. There's plenty of exhaust backpressure theory out on the 'net.

Matt

 

Lets see some pics of this beast!
Please tell me you have taken that one to the track. If so post a slip, I would love to see how that thing does 60', 1/8 and 1/4. With the AWD it must be a rocket.

 

Here is the slip;



and here is the car;





enjoy.

 

dayumn urban...big pimpin...first the VR-4 now the FI G coupe

 

Here are some thoughts from someone that drove a stock 6MT G for 2 years and then instantly upgraded to a Vortech S/C with Injen true dual exhaust with high flow cats...

The stock torque of the car at the wheels is about 225 lb/ft so driving the Vortech equipped G it is quite noticeable at any RPM that there is a definite increase in torque over stock. My car dyno'd at ~300 lb/ft (@5.7 psi) which by the dyno I attached you can see is reached at around 4800 RPM's and held all the way to redline. However you should notice that at 2800 RPM's there is already ~240 lb/ft so between 2800 - 4800 RPM's you are only increasing another ~60wtq.

As for the horsepower you can see how linearly it climbs to a peak of 366 whp (@5.7 psi) at around 6400 RPM's.

I also have dyno sheets from a dynapak dyno that negates any traction factors of the dynojet and gives you "chassis" power numbers. These graphs basically mirror the hp and tq curves seen in the dynojet with slightly different numbers.

In my opinion the Vortech setup has plenty of torque compared to stock and the "area under the curve" is very respectable. Additionally as others have said I can drive around with very little boost by keeping the RPM's low and therefore the car behaves like stock when considering fuel economy. The Vortech builds boost with RPM's whereas a Stillen twin-screw uses a blower with fixed displacement regardless of RPM.

My first attempt to track my Vortech G was last weekend but unfortunately Mother Nature didn't want to let that happen My rescheduled date for the track will be April 14 or 15 so I will let everyone know how this turns out.

I will be heading to the dragstrip this weekend to see how she does over the 1/4 mile (with the PIAA 19's). Hopefully within the next year I plan on getting a set of track tires/wheels and possibly some other upgrades along the way like intake and a bigger FMIC (and injectors may be a needed next step as well).

 

BeerViper-

Those are very good comments and it is nice you backed them up with the dyno too. It is one of the most smooth dyno's I have seen for the Vortech. For the money the Vortech still appears to be the best bang for the buck.

The only things I don't like about it are the lag (mostly because of my driving situation) and that you have to tap an oil line into your block to install it; that always scared me since I did the install myself. But is is a great kit and you don't have to change your hood. If the Stillen fit under the stock hood there would be a lot more of them on the road.

Let us know how your track trip turns out. When you do, please tell us the elevation since that can change things a lot. Good Luck!

 

Wow Urban - you only ran a 17 second quarter with all that power.

OK, seriously that thing is sweet. Nice work!