Paxton or Vortech... please explain your boost curve

[gimmie11s]

Getting ready to buy a power adder and still VERY torn on a paxton/vortech kit or the on3 twins. My experience is with turbos and i absolutely love everything about them. I dont need advise on how "they require more maintenance" or any of that false nonsense.

What i have never owned is a centri power vehicle. I LOVE the completeness of the paxton/vortech setup, how much R/D has been put into the system, how easy it is to spit out 600rwhp and basically everything about the centri idea EXCEPT for a few issues:

1. The way boost comes on
2. The fact that turbos are more efficeint and require no belts
3. Percieved tuning issues due to MAF location

So my questions are:

1. How much boost do you see with a centri at 3000, 4000, 5000, 6000, and 7000 rpm? Is it a linear curve where at 3000 rpm you have 2 psi, 4000 rpm you have 4 psi, so on and so forth? If so, that sucks.

2. Why doesnt anyone use the MAF in a draw through vs blow through?

Thanks much

 

[gimmie11s]

No one?

I'll check youtube and see if there are any vids showing a WOT pull from inside the car with a boost gauge...

 

[GHIG'13]

1. How much boost do you see with a centri at 3000, 4000, 5000, 6000, and 7000 rpm? Is it a linear curve where at 3000 rpm you have 2 psi, 4000 rpm you have 4 psi, so on and so forth? If so, that sucks.

Did a wot run today watching my boost gauge and this is essentially the way it went. Gauge showed 9.4lbs of boost at 7000rpm and I have the torque booster setup.

 

[mebcop]

1. How much boost do you see with a centri at 3000, 4000, 5000, 6000, and 7000 rpm? Is it a linear curve where at 3000 rpm you have 2 psi, 4000 rpm you have 4 psi, so on and so forth? If so, that sucks.

Did a wot run today watching my boost gauge and this is essentially the way it went. Gauge showed 9.4lbs of boost at 7000rpm and I have the torque booster setup.

This didn't answer his question whatsoever... lol

Yes OP, the boost is low at 3000 rpms and slowly builds to redline. That's how they work. On the few I've ridden in/drove, it didn't even feel boosted until over 5000rpms. But the TQ booster kit helps that some, but still nothing like a PD blower. I PERSONALLY find the boost curve of a centri very boring. Some people like it because you are less likely to blow the tires off at lower rpms, and the slow boost increase helps keep traction, but a good set of tires goes a long ways for either setup.

 

[gimmie11s]

Thats what i was afraid of and that has to be a pain in arse to tune around. Kind of bummed about that. The torque booster idea is also strange to me because all you are doing is making a less efficent power adder (blower vs. turbo) even more "less efficient" lol. Venting charged air via a wastegate to maintain a desired boost level is also going to be loud and annoying... would probably sound like a blow off valve permanently open.

A PD blower would be great but theyre so damn expensive.

I know the centri's work and have proven themselves over and over but the whole idea just aint right in my OCD mind.

 

[bam2012@TBR]

With any aftermarket exhaust you will NEVER hear the wastegate open. I love the way the power comes on with a paxton, my 12 with paxton 3.15 pulley, 11.7 spring on e85 was a beast on the street, never got to run it at the track. My 14 is still n/a, but will have a vortech soon.

 

[mhyjek]

Edited post with graph sorry about my original #s being off...
Boost curve on my setup via a dyno graph
3k= 2.5, 4k= 4, 5k=6, 6k=7.5-8, 7k=10 7300=10.7, Made 649 whp at 7350 wtq 499.7 at 6050 dyno jet dyno



Boss IM, Stainless works LT's catted with stainless catback 3.8 pulley
Will being going WG setup tomorrow will dyno and post next week.

 

[gimmie11s]

Boost curve on my setup via a dyno graph
3k= 2.5, 4k= 6, 5k=7.5, 6k=8.5, 7k=10 7300=10.7, Made 649 whp at 7350 wtq 499.7 at 6050 dyno jet dyno

Boss IM, Stainless works LT's catted with stainless catback 3.8 pulley
Will being going WG setup tomorrow will dyno and post next week.

6psi at 4k i think i could live with.. thats not bad at all. This is on the stock pulley? Paxton or Vortech?

 

[BornCoqui]

6psi at 4k i think i could live with.. thats not bad at all. This is on the stock pulley? Paxton or Vortech?

Judging by the pulley size , id be willing to bet it's a paxton car.

 

[Angry50]

Judging by the pulley size , id be willing to bet it's a paxton car.

I till don't fully understand the differences between Paxton and vortech..

 

[PC03GT]

Paxton has a bigger head unit. At 4000 I'm making at least 6 to 7 psi and I have a vortech.

 

[Angry50]

Paxton has a bigger head unit. At 4000 I'm making at least 6 to 7 psi and I have a vortech.

so would vortech be better? or does it depend on application?

 

[PC03GT]

It's all preference, I would just go paxton. The power numbers are slightly higher than the vortech and you have tons of room to grow if you want to make big power.

 

[mhyjek]

Yes paxton stock pulley until tomorrow then going wastegate with a 3.33 pulley so at 4k=7.5-8 by 5k=9.5-10 then hold 10.3 all the way through.

 

[mebcop]

OP, simply google "2011 mustang Paxton dyno sheet". By looking at those dyno sheets, I don't see how people are going from 2.5psi at 3krpms to anywhere close to 6psi at 4krpms.

Example 1:

Example 2:

 

[slow306stang]

My D1sc before wastegate made...

3500rpm 2.8psi
4000rpm 3.6psi
4500rpm 4.3psi
5000rpm 5.1psi
5500rpm 6.0psi
6000rpm 7.0psi
6500rpm 8.1psi
7000rpm 9.5psi
7300rpm 10.1psi

I know its not a Paxton or Vortech but the head unit falls in between both of the them in my opinion.

 

[gimmie11s]

So am i correct in thinking that the vortech will come on sooner (more boost at lower RPMs) due to the head unit being smaller?

Example at 4000RPM the vortech might make say... 6 psi where at 4000RPM the Paxton is making 4 psi.

 

[mhyjek]

Yeah stock should be right also one pulley smaller and you should be perfect!

 

[lovebread]

Keep in mind by default the Vortech kit also has a 3.6 pulley vs Paxton 3.8.

With centrifugal systems (minus Procharger i-1) the head units build boost by progressively spinning faster until you let off the gas and the excess gets vented out of the system. At the same time you'll only use fuel when you need it (depending on BAP) so you'll see better fuel economy than a twin screw/roots system.

Issues:
1. Roots vs Centri

WHOOPS posted roots vs turbo.

2. Things break regardless of setup, or they don't and you'll have no issues. Crapshoot in the aftermarket world.

3. It says clock the MAF straightener pipe in a certain direction so many times I don't even understand how this is an issue. Yeah it sucks to tune but pick a good tuner and they'll be familiar with the system.

Q

1. Depends on how your kit is set up, you'll see about 2psi per 1k rpm past 2k rpm

2. IIRC procharger has the MAF in the IC?

 

[GHIG'13]

Yes paxton stock pulley until tomorrow then going wastegate with a 3.33 pulley so at 4k=7.5-8 by 5k=9.5-10 then hold 10.3 all the way through.

mhyjek, doing a 40mph, third gear wot pull the other day on the street I only saw 9.4lbs of boost and didn't see it until 6800-7000rpm. Wonder if something is not right with mine because I haven't been impressed with it since installing my torque booster kit.