Polaris Slingshot Forum banner

1 - 20 of 45 Posts

·
Registered
Joined
·
4,125 Posts
Discussion Starter #1
For those people that have asked....

Here is a video that briefly describes how to switch over your Alpha Turbo System from the 1bar MAP set-up to the 2bar MAP setup.


The video portion of showing the wastegate is hard to see because of how dark the video turned out. The link to below instructions from Precision will help with understanding on how to change out the springs to produce more boost. Switching large yellow for large red.

http://www.precisionturbo.net/tech/instruction-manuals/PTE-PW39-Wastegate-Instructions.pdf

I am sure the Alpha team (@Turbosling and @[email protected]) will have some official instructions. This can serve as a starting point and they can chime in here to give even more clarity.

The 1bar setup was working great, but the 2bar is more refined in tuning and is pushing another 3 lbs of boost. If you want to switch over, reach out to the Alpha Team and they will get your started on the process.



 

·
Registered
Joined
·
4,125 Posts
Discussion Starter #4
What have you noticed with the alpha turbo and the two bar tune? Sound of engine, blow off valve sound change, drivability, speed, etc...
Improvements all around. The tune is much better with this setup. It idles smoother, there is less popping, the AFR numbers look better, and there is a lot more power.

Because you run around 3lbs more of boost with this setup, you get better sounds from the motor and BOV. It diffenetly sounds more evil!

The 1bar treated me fine, but IMHO there are 0 reasons not to go to the 2bar setup.

 

·
The Pack
Joined
·
5,165 Posts
Improvements all around. The tune is much better with this setup. It idles smoother, there is less popping, the AFR numbers look better, and there is a lot more power.

Because you run around 3lbs more of boost with this setup, you get better sounds from the motor and BOV. It diffenetly sounds more evil!

The 1bar treated me fine, but IMHO there are 0 reasons not to go to the 2bar setup.

You're not worried about engine durability?
 

·
Registered
Joined
·
4,125 Posts
Discussion Starter #6
Not at all. Because the tuning is better, you will have probably get better longevity from the motor with a 2bar map sensor and tune.

From what I am told, you can run the 2 bar tune and map sensor and keep the boost level exactly the same as what you are running now. So, in theory you could run either a 5lb boost 2bar map setup or, change to a new red spring to run around 8lbs like most will do.

@Turbosling can chime in if I am not understanding this correctly.
 

·
The Pack
Joined
·
5,165 Posts
Not at all. Because the tuning is better, you will have probably get better longevity from the motor with a 2bar map sensor and tune.

From what I am told, you can run the 2 bar tune and map sensor and keep the boost level exactly the same as what you are running now. So, in theory you could run either a 5lb boost 2bar map setup or, change to a new red spring to run around 8lbs like most will do.

@Turbosling can chime in if I am not understanding this correctly.
You're dead on. I've been talking to him. He did say that 8 pounds will put you above that 300 hp threshold. It may be safe for several years if you got a good engine. If you got a marginal engine you're still at risk of blowing it. That being said, I really want it.
 

·
Registered
Joined
·
4,125 Posts
Discussion Starter #8
I am currently not worried about my engine. If that sucker was going to blow, it probably would have happened in the last couple of weeks. All the AFR data and boost levels look super consistent. No boost creep to worry about either.

I still think I am under 300hp, but the dyno numbers I will get soon will tell. I am going to try to run it right around 265-275hp at the wheel. I think that is the magical number for quick and no motor issues.

For sure get it! You wont regret it!!!
 

·
Registered
Joined
·
4,597 Posts
The two bar tune is better and does run better even at 6psi.

I've been quiet on upping the boost for a long time and have not put too much effort into it because although fun and it does make more power their is a chance of your engine going boom. Right now at 6psi if you boost crept it wouldn't be enough to blow your engine. But when you get to 8-9psi if you did boost creep chances are good.

It's a risk with modding any vehicle and I've blown up enough of my own engines in my earlier years to know better now it has to be done right and with the right supporting mods.

So with that said is stage two with two bar setup fun hell yes! Its allot more power but just keep in mind that the chances are also higher.

If your goal is a Lil more power with longevity in mind I say go for stage 1 with a two bar tune. If your power hungry and don't mind down time and possibly the expense of a new engine stage two.

I love power and their is no such thing as too much but you are all great friends and the last thing I want is to sell you something that could cause a big headache and expense.
 

·
Registered
Joined
·
557 Posts
The two bar tune is better and does run better even at 6psi.

I've been quiet on upping the boost for a long time and have not put too much effort into it because although fun and it does make more power their is a chance of your engine going boom. Right now at 6psi if you boost crept it wouldn't be enough to blow your engine. But when you get to 8-9psi if you did boost creep chances are good.

It's a risk with modding any vehicle and I've blown up enough of my own engines in my earlier years to know better now it has to be done right and with the right supporting mods.

So with that said is stage two with two bar setup fun hell yes! Its allot more power but just keep in mind that the chances are also higher.

If your goal is a Lil more power with longevity in mind I say go for stage 1 with a two bar tune. If your power hungry and don't mind down time and possibly the expense of a new engine stage two.

I love power and their is no such thing as too much but you are all great friends and the last thing I want is to sell you something that could cause a big headache and expense.
Thanks Henry!! You convinced me to stay with Stage 1 with the 2 bar MAP sensor/tune. FEDEX depicts me receiving my turbo kit this Friday. Hopefully you or Andy can get down to Interstate Cycle in Mooresville NC early next week for the install.
 

·
Registered
Joined
·
5,881 Posts
The two bar tune is better and does run better even at 6psi.

I've been quiet on upping the boost for a long time and have not put too much effort into it because although fun and it does make more power their is a chance of your engine going boom. Right now at 6psi if you boost crept it wouldn't be enough to blow your engine. But when you get to 8-9psi if you did boost creep chances are good.

It's a risk with modding any vehicle and I've blown up enough of my own engines in my earlier years to know better now it has to be done right and with the right supporting mods.

So with that said is stage two with two bar setup fun hell yes! Its allot more power but just keep in mind that the chances are also higher.

If your goal is a Lil more power with longevity in mind I say go for stage 1 with a two bar tune. If your power hungry and don't mind down time and possibly the expense of a new engine stage two.

I love power and their is no such thing as too much but you are all great friends and the last thing I want is to sell you something that could cause a big headache and expense.
He speaks the truth. I have made a post in the past publicly to let people know I'm pushing past Hahn's recommended limit. I didn't want mine exploding and then it looking bad for Hahn. I am at 10 PSI now and its not any different in the first 2 gears. Third is a bet stronger and 4th is where the extra boost shines. However that is exactly when you can tell the engine is having to work the hardest.

I think Alpha and Hahn both have set a fairly safe limit. I'm just pushing it a bit further. I have another engine in my barn laying on a old tire. I guess if mine pops ill be busy for a day or two.

But before it goes in it will be bulletproof to 16PSI. You can bet on that.
 

·
ALPHA - Home of the V8 Slingshot
Joined
·
3,160 Posts
Thanks for all the info @TravAZ

TIP:
When installing the new spring in the wastegate its very hard to get the cap back on by yourself because its at an angle and under pressure from the spring and you cant reach it easily. Rather than asking the wife to start a screw, cross thread it and cause a divorce, I went and bought 2 new bolts 2.5 inches long and installed them opposite sides and take turns on them and tighten the cap down to where you can use the screws it came with, after you get those 4 in take the long screws out and put the stock ones back in.
 

·
Registered
Joined
·
4,125 Posts
Discussion Starter #13
Thanks for all the info @TravAZ

TIP:
When installing the new spring in the wastegate its very hard to get the cap back on by yourself because its at an angle and under pressure from the spring and you cant reach it easily. Rather than asking the wife to start a screw, cross thread it and cause a divorce, I went and bought 2 new bolts 2.5 inches long and installed them opposite sides and take turns on them and tighten the cap down to where you can use the screws it came with, after you get those 4 in take the long screws out and put the stock ones back in.
Good thinking!
 

·
Registered
Joined
·
4,125 Posts
Discussion Starter #15
If it was stated I am sorry, but anyone noticed a major reduction in fumes?
Because the tuning is better and the AFR numbers are more consistent across the board, you should notice a slight reduction in odor. I noticed it at idle.
 
1 - 20 of 45 Posts
Top