APS TT if you have the money for it. Why even consider Vortech SC . . . .

 

yeah i dunno, it's not like the vortech can make good numbers

especially when the kit and install is 2/3 the cost

 

Decisions, Decisions, Decisions. AAhhh Yesss!!! 4.2L Stroker kit with the APS TT. Perfect.

 

aps twin turbo if it's really a hard choice!

 

people on this board love to jump on the band wagon...scrolling throughthte thread..the buy will probably stick with a stock block and is also looking at cost, whcih makes the vortech better for his goals

 

I'm glad you brought this up. I was consider the Vortech kit because they are just down the street from me and because it is CARB legal. But, I been reading all this threads, specially the sticky one titled "How to do Twins right the first time!!!". I know this is titled twins, but I was wondering if this applies to SCd cars too? I know it will be good to go that route but is it necesary? Can I keep the motor the way it is if I don't plan to run more boost than what it is set up for?

 

welll SC make power in a different way than Turbos...
SC altought it limits you down the line as far as how much power you can make compared to turbo it has better response...
twin turbo kits are about 1500$ more than superchargers and probably cost about 1000$ more to install, which you could use that money to get all you other suporting mods for a s/c setup.
I personally like turbos myself, but in my case i know i am going to builkd my block.
Again it just depends what you are looking for, but sounds like S/C is better for what you look for

 

So keeping the stock block is good with low psi (as a rule of thumb < 8 psi) on s/c or turbo'd?

 

i say this all the time, but IMO stock boost on the vortech isn't going to be very impressive. It'll be faster, but you really won't notice it until you almost redline the car

if you upgrade the vortech's pulley and other things like gearing, flywheel, exhaust, and tuning, then it'll be much more noticable and worthwhile for everyday driving that you'll notice without having to practically redline the car to feel a good oomph of boost

living in CA, it would be a pain in the *** to get stopped by a cop and asked to pop your hood with the APS TT kit and then end up having to spend the expensive labor to uninstall it just so you can show the court you "fixed it"

 

No sir. The APS kit will give better response at every RPM - centrifugal blowers make boost based on RPM and thus don't make peak boost until very close to redline. The APS TT kit usually makes peak boost by 2500rpm - the vortech centrifugal SC isn't even thinking about making peak boost that low, hell it's probably not making more than 2-3psi then. In any gear, at any speed, in any RPM range an APS TT car would annihilate a vortech car.

 

Thing is - the APS TT kit is so damned stealthy that I really truly doubt a cop would even know it was there unless he really really really knew what he was doing. It looks like a frickin cold air intake to 99% of people unless they notice the IC, which itself is much less blinged out than most FMICs.

 

i dunno, it'd be your choice if you'd chance a cop not hearing your turbo or seeing the intercooler. You'd think cops would actually be trained to look for intercoolers and listen for BOV's and things like turbos since the whole CARB thing is a big money maker for the state with catching people modding their car illegally

Even if the cop thinks the APS kit is just a cold air intake, he's still going to ask you if you have CARB stickers or papers for that "CAI" that you won't be able to give him. It'll just end up costing you a lot of money and hassle.

that may be so unless the vortech is making more boost (except under 1800-2000 rpms where the APS is making 0 boost and the vortech is making around 1 psi, not to mention if the APS was running a huge exhaust with test pipes and short turbo exhaust manifolds, it'd have less power down that low on top of running 0 psi).

There's lots of people running 12 psi with the vortech on the stock block mainly because you don't run to redline as often as you at mid rpms which would be making anywhere from 7-9 psi from 4000-5000 rpms which is plenty of boost to feel it. On the occasions that you do go drive all the way to redline, you'll be hitting 12 psi if you have it set up that way which IMO even the stock block can handle just fine if you run decent gas and have the supporting fuel system and cooling.

the usual arguement is you can run 12 psi on the APS TT too, but how many people run 12 psi of twin turbo power on a stock block on a daily basis? Not a lot because it's going to put out probably too much power to be safe and you'd hit 12 psi really early in the rpms, which means for daily fun you'd be reaching the full 12 psi quite often at low-mid rpms where the engine has a hard time getting all that exhaust energy out of the engine because it isn't spinning very fast

it's not too hard to just downshift a gear with a vortech anyway. People brag about how TT's build full boost at 2500 rpms, but no one likes to run full boost at 2500 rpms because it's hard on the engine. If you're driving 75mph in 6th gear on the highway, no one likes to go WOT in 6th gear because of the risk to the engine. So I'm not sure why it's such a dramatic bragging right. Even launching at the dragstrip with slicks, you're going to launch at 4000-5000 rpms anyway so there again there's no advantage to getting full boost at 2500 rpms

If you change your gearing to something more aggressive, you'll be higher in the powerband anyway as well as have the more aggressive gearing for more gear torque and response which compliment the vortech and again, it's perfectly legal in CA. Also with a TT setup, if you have to run the stock cats which is the law in CA, it's going to be much more of a restriction with TT's power output and it's ability to spool quickly (both in terms of full boost early and overall throttle response).

It's not that I'm against TT's or anything. I would have went with a TT if my car didn't have so many vortech friendly parts in the first place. But so many CA people have really shot themselves in the foot by going ST or TT which aren't CARB legal and then get pulled over or simply being parked at the wrong place at the wrong time when police were searching all cars on a street or parking lot and blocking you from leaving until they were done...

it's true that the APS TT kit will be more capable of outputting huger power, but if someone is concerned with making huge power, they're not concerned with getting a FI kit on a small budget

 

Neloc ovbiously likes the aps kit so its going to be hard to argue since he isn't going to bend in any point... i never said the vortech was better and kicks aps in the *** like you make it sound..i jsut pointed the points where its more favorable for what this person is looking for.

 

You're right I do like the APS TT kit a lot better than the Vortech SC kit, but the point was that you said the SC kit was going to have better response which is completely and entirely false. The APS TT kit will have better response as it has more power available at any RPM. I was just correcting the incorrect info you gave to the original poster.

 

I agree with what you said for the most part, it's not a good idea to go lugging the engine around at 2500rpm boosting in too high of a gear, I was just correcting quicksilver's bad info where he said that the SC car would have better response than the TT car, because it won't.

Also, there are situations in which having boost that low is a benefit. Say you were to race someone from a very slow roll like if you started out from a light and you weren't sure if the other guy was going to race so you weregoing 10mph in 1st gear when you both hit it, or if you'd just shifted to second gear and were at like 3000rpm - the TT car would have a significant advantage in both scenarios.


Performance wise, the APS TT is the clear winner in every concievable scenario, this of course comes at a higher price though, and also the legality issues. If someone lives in a state where this is an issue then it is a huge consideration as to what one should purchase.

 

well yeah, but the issue most people on the street with turbo have because of the high torque at mid rpms, when you floor it in 1st or 2nd gear you usually don't have traction so you have to modulate the throttle

So you can either go half throttle in 2nd gear with a TT, or full throttle in 2nd gear with a vortech.



In my case though for what it's worth, my vortech Z is higher hp than most vortech setups. It breaks traction in 2nd gear from about 5000+ rpms and I'm running 295 wide competition tires that are barely street legal with a nismo LSD. Though it does seem to give you a split second to react since the boost builds up in a more gradual way instead of suddenly handing it all to you at once

I don't have a higher reading dynojet dyno, just a dynodynamics dyno that shows I have 260 tq at 2500 rpms and 340 tq at 4000 rpms. On a dynojet that's probably around 275 tq @ 2500 rpms and 360 tq @ 4000 rpms which isn't all that much less than most normal APS TT cars, especially when you consider my gearing has 10% more gear torque

I don't even use 1st gear anymore (worthless for all FI Z/G's at WOT) unless I want to do a burn out, or start the car from a stop on a hill, or am in rush hour and am driving very slowly. I start the car in 2nd gear and even at part throttle, there's enough power being made and enough gear torque with the 3.9 FD to get the the car going fairly smoothly as long as you keep the revs at 2000+ rpms. I don't think you'd be able to do that as smoothly with a TT setup with taller gearing and extremely open exhaust unless you maybe have a big stroker kit or something

so for that 10mph situation where a TT setup would be at 1700 rpms in 1st gear, I'd start the race in 2nd gear @ 1200 rpms because of my gearing and I can pretty much go WOT most of the time up to around 56 mph without shifting. The TT would have to part throttle 1st gear to 38 mph, then shift into 4000 rpms in 2nd gear while I'd already be at 5000 rpms in 2nd about 5-6mph faster. Running warm drag radials would probably put the TT car at an advantage over my type of setup though

 

I'm used to riding around in a Z with DRs on it (and I have DRs on my own car) so traction on street tires was something I hadn't taken into consideration but it's a good point. Not an issue with either "kit" per se, but an issue with overall setup that one needs to consider.

 

yeah I've always felt that TT and ST setups are going to almost require drag radials to put the huge sudden torque down to the ground and really jump off the line hard with lots of throttle.

While the vortech setup is usually perfectly happy to run with normal street tires which will be better at handling high speed cornering and rain, but won't jump off the line as hard. Once up to speed and in the powerband though - which doesn't take long anyway, the vortech is still pretty fast

 

Wrong. I run -2 degrees of camber and with 285/35 19's I could hit it from a first gear roll with 400whp and the TN set-up and dead hook. Id imagine with better camber I could easily put down more power on the same non drag radial tire.

 

I used to be a pro supercharger guy, but after all the research it's TT all the way for me. I would go JWT, but APS is a close second. Of course you have the CA issues we don't.