Dodge SRT Viper Forums : ViperAlley banner
Cancel
Create thread New Garage Forums

Virtual Works Racing Twin Turbo Viper Build.

Jump to Latest
141 - 160 of 399 Posts
Discussion starter · #142 ·
Seb@NLR said:
nice I like it!! Your right....I can tell you thats the only viper with 60mm gates and those turbos anywhere in the world.
Click to expand...
Yes and let me tell you I can see why. Besides the fact of them being the only set of turbos around (unless you got yours already), there is nothing fun about fitting these things with 60mm gates! Well I guess the hardest part is trying to make it fit with 4" air intake piping to the front of the car. We will see how that turns out...
 
#145 ·
Tiago said:
why did you guys choose the 60mm gates? seems like way overkill?
Click to expand...
maybe overkill for some gt35's or some turbos with some back pressure to them. When you go to a gt45 turbine wheel with a tial 1.16 stainless housing that flows a ton in combination with the 45 turbine wheel and you want to be able to get the boost as low as possible then 44's I dont think will cut the mustard.

Running the smallest spring possible to net the lowest amount of boost is the best way. Then use control to raise the boost. This way you can maximize traction everywhere.
 
#146 · (Edited)
Seb@NLR said:
maybe overkill for some gt35's or some turbos with some back pressure to them. When you go to a gt45 turbine wheel with a tial 1.16 stainless housing that flows a ton in combination with the 45 turbine wheel and you want to be able to get the boost as low as possible then 44's I dont think will cut the mustard.

Running the smallest spring possible to net the lowest amount of boost is the best way. Then use control to raise the boost. This way you can maximize traction everywhere.
Click to expand...
If your wastegate placement is well done, the driving force should be the stagnation pressure of the gas, not the backpressure behind the turbo. That being said, too big isn't a bad thing. Doc1's T6 car has 46s if I remember right and has no problems with running low boost. It also has the wastegate in the ideal position to take advantage of the stagnation pressure, so that isn't surprising.
 
Save
Reply Quote Like Like
#147 ·
Seb@NLR said:
maybe overkill for some gt35's or some turbos with some back pressure to them. When you go to a gt45 turbine wheel with a tial 1.16 stainless housing that flows a ton in combination with the 45 turbine wheel and you want to be able to get the boost as low as possible then 44's I dont think will cut the mustard.

Running the smallest spring possible to net the lowest amount of boost is the best way. Then use control to raise the boost. This way you can maximize traction everywhere.
Click to expand...

I understand why run the lowest springs possible, but 60 just seems like a lot :D

those are some bigsumbitches :D
 
#148 ·
Tiago said:
I understand why run the lowest springs possible, but 60 just seems like a lot :D

those are some bigsumbitches :D
Click to expand...
Biggest reason is so we can get the boost pressures low enough to drive our cars on the street. (on pump fuel) A friend of ours tuned a car with standard gt45's which flow alot less air than these turbos, and that car made 1600hp at the wheels on around 20-22lbs boost. which means we will probably have to run somewhere in the area of 6-8psi on pump fuel and will be around 1000 hp at the wheels. We want to be able to gate down to hopefully 2-4psi. Letting the AMS 2000's do the boost control!

No do not have my turbo's. Frank got the first set. Mine were built last week. So hopefully will be here sometime this week. Good thing is i have a gen2 gts so i have a little more room to fit my turbos. LOL But i guess me and SEB will have some fun.
 
#149 ·
Ben @ VWR said:
Yes and let me tell you I can see why. Besides the fact of them being the only set of turbos around (unless you got yours already), there is nothing fun about fitting these things with 60mm gates! Well I guess the hardest part is trying to make it fit with 4" air intake piping to the front of the car. We will see how that turns out...
Click to expand...
Ben
You guys do some really nice work! I have to give you props!
 
#150 ·
The Former PFR said:
If your wastegate placement is well done, the driving force should be the stagnation pressure of the gas, not the backpressure behind the turbo. That being said, too big isn't a bad thing. Doc1's T6 car has 46s if I remember right and has no problems with running low boost. It also has the wastegate in the ideal position to take advantage of the stagnation pressure, so that isn't surprising.
Click to expand...
The overall flow capability of a 44 mm gate is not enough to discharge enough exhaust gas to keep that turbo down in the 4 psi range especially at 8-8500+ rpm so a v60 was utilized. Put it this way...on a 70 cubic inch motor( gt35r with a .82 ar turbine housing) that spins 13000 rpm I can barely keep the thing at 5psi to redline. My gate is in the best position you could ever ask. All cylinders fire either at the valve face or right next to it and 2 of the exhaust ports are withing 5 inches of the valve face :)
Now move to a 261 cubic inch engine with a gt45 on it . I wasnt taking any chances lol.

Stagnation as fluid stagnation? Im talking exhaust gas pressure. Back pressure pre turbo not after it. Yes I agree that prioritizing the wastegate in a set up leads to better results when trying to evacuate exhaust gas. However gate sizing is still important. Like you said there is no draw back to a large gate if you have the proper boost control system. With a iffy system the amount of exhaust gas a LARGE gate will dump can create poor boost curve that swings up and down.

I can control the pressure in the top can within a tenth of a psi. If you factor that into the valve position its pretty rediculous how tight of a position I can keep it.



If it was a 6200 rpm motor maybe but we are not taking any chances.
 
#151 ·
This is all great, I just hope you have a driver capable of driving the car to its potential. I've said time and time again that once over 1k, the driver component is incredibly underrated.
 
#153 ·
Seb@NLR said:
Stagnation as fluid stagnation? Im talking exhaust gas pressure. Back pressure pre turbo not after it. Yes I agree that prioritizing the wastegate in a set up leads to better results when trying to evacuate exhaust gas. However gate sizing is still important. Like you said there is no draw back to a large gate if you have the proper boost control system. With a iffy system the amount of exhaust gas a LARGE gate will dump can create poor boost curve that swings up and down.
Click to expand...
Stagnation pressure - Wikipedia, the free encyclopedia

Stagnation pressure is the pressure experienced by stopping a moving fluid. Sorta like what you feel by putting your hand out the window, but not exactly. The fluid's velocity turns to pressure when you put a wall in it's way. This added seat pressure can be considerably bigger than the actual backpressure in the system.

As you said, as long as the control system is there, too big isn't a problem. I can see what you're saying if you're trying to hold 4 psi at 8000(+) RPM.
 
Save
Reply Quote Like Like
#154 ·
The Former PFR said:
Stagnation pressure - Wikipedia, the free encyclopedia

Stagnation pressure is the pressure experienced by stopping a moving fluid. Sorta like what you feel by putting your hand out the window, but not exactly. The fluid's velocity turns to pressure when you put a wall in it's way. This added seat pressure can be considerably bigger than the actual backpressure in the system.

As you said, as long as the control system is there, too big isn't a problem. I can see what you're saying if you're trying to hold 4 psi at 8000(+) RPM.
Click to expand...
so in simple terms, are you saying that if the WG is prioritized that the pressure of the exhaust directly hitting the gate is greater than the overall pressure in the exhaust?

i'm just trying to keep up here, lol
 
#156 ·
sagev viper said:
so in simple terms, are you saying that if the WG is prioritized that the pressure of the exhaust directly hitting the gate is greater than the overall pressure in the exhaust?

i'm just trying to keep up here, lol
Click to expand...
Yeah, if the gate is placed in the path of the flow (rather than 90 degrees off of it, like turbo systems), quite a bit of additional pressure can exist at the valve face.
 
Save
Reply Quote Like Like
141 - 160 of 399 Posts
About this Discussion
398 Replies
71 Participants
Last post:
Viper4Christ
Dodge SRT Viper Forums : ViperAlley
posts
2.1M
members
35K
Since
2003
A forum community dedicated to Dodge SRT Viper owners and enthusiasts. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
Viper Discussions - Gen I & II Viper Discussions - Gen III & IV SRT Viper Discussions - Gen V SRT 2013-up The Track Viper Wheels and Tires