Do you have issues of Boost creep on the Vortech system. I know that boost creep is very common on any turbocharged system due to the wastegate, possible leaks, etc.

 

Define "Boost Creep"

I have not heard that term yet...

 

Turbo does not have a linear power curve like Vortech which need to hit the High RPM just to hit full boost. Look at the Dyno chart of a Votech/Stillen/ST/TT you'll see the differences were the power starts.
--Wrong. Look at the APS Twin Turbo kit. also, having a linear responce isnt dictaed by parts in the kit, but by the turbos and tuning themselves.

honeslty, TT kit puts out moer torque then a SC which is why i prefer and am going TT. If you do it properly and use good parts, it can be just as safe as a SC.

 

i'm reposting a post i made on another forum last week:




i really don't think one setup is better than the other, but just different. I think turbos are great, and have a lot of definite advantages especially if you're trying to turn the car into a rocket with a million hp, but there's also some disadvantages that for the rest of us mortals are worth considering

turbos produce a LOT more heat. Heat is bad. Building up heat can heat the engine up especially if the turbos are right next to the engine in a compact engine bay. The turbos get red hot. They spin 2-3x as fast as superchargers to create more boost than what's needed and then send the extra wasted power out the wastegate. So you're creating more heat for something you're not really using. For some people that live in hotter climates, maybe they don't want that extra heat in their engine bay during the hot summer.

Compared to most superchargers, turbos produce full boost earlier where the engine's peak torque band is which means at around 4500 rpms the torque is MUCH higher than on a SC. Torque can break parts - which we know is a half truth cause boosting at high rpms can break things too which both SC's and turbos are going to do. If a car could be setup to run 800 tq and 400 hp, it'd blow much sooner than a car with 400 tq and 400 hp. Turbos actually produce a little more boost at 4000-4500 rpms than they do at redline from the graphs I've seen. Combine that with the engine naturally making more torque in that rpm range and it's no wonder turbos have so much more torque - and torque is how much force the engine is outputing without the frequency (rpms) factored in

But bottom line is we all know turbos produce more power across the entire power band and thus it's safe to say that stresses the engine more. We know superchargers have parasitic losses, but not enough to make up for a 70 ft/lb of torque advantage

An engine will be able to pump more air thru it at higher rpms. A turbo produces full boost early then pretty much holds it to redline though it does drop as rpms rise. So if the turbo spools up throwing full boost into the engine at 4000 rpms, it will stress the engine a LOT more than throwing that amount of boost into it when the engine is working at 6600 rpms and can deal with the load better. A centrifugal SC IMO is matched up perfectly with what the engine can handle because the boost is linked directly to the rpms, not exhaust gas velocity. Shoving 10 psi into the engine at 2000 rpms when it isn't breathing very fast can stress the engine, but at redline that's no sweat. That's why cams work so well with FI - they let the air in and out of the engine a better way

Another thing is that boost isn't always boost. All a boost gauge can read is pressure, not how much total volume of air is actually moving thru the engine. Think about it, you could punch a pin hole into a coke can that shoots out liquid at a higher pressure than if you turned a bucket of water upside down despite the bucket outputting a LOT more water. A guy with a supercharger only running 8 psi of boost is completely capable of making a LOT more power than a guy with turbo running 12 lbs of boost - it all depends on how good the breathing is.

turbos NEED bigger intercoolers. Turbos spin so fast and compress the air so much that the air is hotter as it approaches the intercooler than on a supercharger. The bigger intercooler means more velocity is lost, though the air ends up being cooler by the time it reaches the engine than on a supercharger. You could put a larger intercooler on a supercharger, but wouldn't be worth it for a centrifugal SC because you'd loose too much air velocity at lower rpms. Then at higher rpms, the tradeoff in less velocity for cooler air usually isn't worth it until you're blowing a lot more power than normal.

about maintenance:
as if tightening the belt is sooooo hard - just do it when you change your oil, a couple quick turns of a wrench
as if changing the pulley is something you do often, and when you do, it's not like it's a big deal.
turbo people scoff at maintenance on SC's until they gotta do the ultimate maintenance - which is to replace/fix their blown engine because I see a lot of turbos breaking rods, but see SC's usually break piston rings which isn't as catastrophic or expensive - you still have a working block. Seems like turbos are generally less maintenance until something goes wrong. And when it does, it goes really wrong


you see SC people swapping to turbo setups because they decide they want MORE power than the average SC person wants and doesn't want to spend the money to upgrade their SC or in the case of the Stillen or HKS - isn't that upgradeable. A lot of turbo guys went SC back before ST's were out because they didn't want to shell out for a greddy TT that was poping motors left and right. It also isn't hard to remove a SC. SC's are completely easy to remove, but removing a TT isn't so easy.


what happens a lot of times is someone steps up into a turbo, ups the boost, gets tuned etc
brag to SC people about how much more torque they have
blows their engine
gets depressed
sells the car or decide to build up their engine and raise the boost
goes great for awhile and hassle the SC guys about how great it is to have 550whp/tq while they're still dealing with their wimpy 370-440whp and 310-370tq
eventually get head lift or breaks a piston ring or breaks some more rods
gets depressed
sells the car or decide to plunge more into more debt but this time reduce the boost a little bit
ends up realizing the car has been in the shop or out of commission more than it's been driven
keeps telling themselves it's worth it

yeah that's overdramatic, but it's kinda at least halfway true at times. It's possible for something like that to happen with SC cars, but usually not as likely since it does take a lot more work to get more power out of SC's - which usually are breathing mods which help reduce stress on the engine by letting it breath easier



it's funny, I'm always hearing about how great it is that turbos spool up so soon, but when asked how much time at 3500 rpms at full boost do people spend in 3rd, 4th, 5th, or 6th gear, everyone always says you want to downshift so that you're higher up in the powerband cause otherwise you're just stressing the engine boosting at such a low rpm in a higher gear. So WTF is up with that? It's an important thing to get full boost early in the powerband, but you don't want to be actually going WOT while in low rpms for very long, so then who cares? At the drag strip you'll end up launching at 3000-5000rpms anyway and we all know 1st gear lasts 1 second. Sounds like no matter what FI you choose you want to obviously be in the upper rpms in the right gear if you want to go fast which is where most SC's make full boost anyway.

I was once on a ST vs TT thread with two very good 1/4 mile drivers who each had a ST and TT. I mentioned that a ST would probably be better at 1/4 mile because they tend to have more midrange power, though less low end power than an equal whp TT. The TT guy said "who cares, you're always above 5000 rpms anyway" - kinda ironic that they brag about having all that midrange power that it turns out you don't even use in the 1/4 mile

50-70mph in top gear is a common test in a lot of magazines use that turbo people should be all over to show off how awesome it is to have full boost at low rpms. But most turbo guys don't want to do that benchmark because of cramming 5-6psi into the engine at low rpms. Also the ECU freaks the hell out sometimes with a lot of boost coming on around 2500 rpms. So far it only seems to happen with the JWT TT kit, but has become common knowledge among the JWT installers that having a lot of boost really early in the rpms will send the ECU into limp mode. Ask VRT, they know.

We've all seen fairly comparable 1/4 mile times in SC and turbo cars. Usually the edge goes to the turbo cars, but then again you see more turbo guys at the drag strip putting out times than SC people. It isn't always about power if you want to go fast.

I think most people like the slingshot effect feel that turbos give them going from 0psi-full boost over the course of 1000 rpms vs a SC going from 1-2psi over that same rpm range. However, once you're going WOT and shifting, you're always in the upper boost range anyway.


A TT is a really nice daily driver. It isn't loud, it boosts early, it gives a lot of torque and power. But it's also expensive as hell and you have 2 turbos, a wastegate, more piping, more heat, etc to worry about should something go wrong that a SC doesn't have. Basically maintenance is going to be a bitch when something actually does go wrong someday. But if you can afford the $8-10k for a TT kit and install then spending the big bucks to fix stuff shouldn't be an issue either.

 

well basically i woudn't say one is more reliable then the other we could debate this for months ....

if you want over 430rwhp then you will have to go turbo below that go with the supercharger...

turbo>supercharger if you want big horsepower #'s

 

you can get over 430whp with a SC, there's guys with over 500whp on a vortech

 

I agree but look where it builds power. The TQ and Hp come on very late in the RPM band. Next thing you know its time to shift. Im not hating on Vortech. Ive owned a Vortech and APS TT. Its night and day. Im now selling my APS due to carb cert and how much drama the local PD has brought on my city. With that being said Vortech has a carb cert. But I wont be doing the Vortech. I would just rather roll stock.

 

The wastegate is there to keep your peak boost to a certain point and you can change that by opening and closing the valve, since an SC doesnt have that nor need one. Pulleys do the work for them. A turbo will boost creep in many cases. For instance, say you want to run 10lbs. You may notice on the dyno that your getting crazy surges after a certain rpm that is likely leaks in the wastegate "boost creep". There could be multiple reasons for that but, that is one.

 

so how much is a complete set of Vortech going to set me back? i think it has been out for a while now, so i would think (hope) that the price would come down a lil by now.

anyone has an idea where you can get the best price for a Vortech SC for a 05 G?

one other question..sorry little off topic; is there any difference between the SC for 03/04 and the 05 with the rev up engine (manual trans)?
im looking into getting a SC in the near future and i have a 05 6 speed.

thanks guys!

 

Youre looking at about 4500 for the kit with FMIC. I would suggest not using the SS box, as many have had problems with it. I would also suggest a better fuel system including injectors.

Hit Chad at Infiniti Specialist up!

 

Nice input there, I think I said most of that to you this morning...lol I have beaten everything I have raced against and that is not much as I do not race that much but G.Ride good luck with my setup and I will help you along the way.

 

You taught me well bro!

By the way, I found a hell of steal on an RFL bov/by-pass valve for us SC people . Anyways, Im thinking about going with it. I dont know about the HKS.