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Discussion Starter #1
I took the car to dyno today. I did not do a stock run on the car. I have seen most guys put down 220 to the wheels.

The first run was done with no cool down of the car or no fans. I drove in, strapped it on and ran it.

First run was 219

Second run we let the car cool down and we used the fans.

228


third run we cranked the boost to 15psi. It dropped down to 13 psi after a few which is why you see the huge increase in TQ but a lower HP.

Fuel was at 11/1. If we can get it to about 12/1 it will run alot stronger. Did some one say AFC? :)


So it looks like the exhaust gave a good 8hp to the wheels which is not to bad. NExt mod is the intake :)

The wastegate was shimmed open a little which I know made me loose some performance. It took me some time to figure out how to set the HKS EVC5 correctly. It has extra vaccum hoses to it. One goes directly to the intake manifold to get a good manifold pressure reading. The problem is taht there are not to many nipples to tap of from. You want a nice dedicated nipple so the signal wont be affected by the BOV etc. I now have it set up correctly and im getting no more fluctuation on teh wastgate. If you get a EBC, get teh profect b, its easier to install.
 

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Not a bad gain, especially with being a prototype exhaust. I know there aren't gonna be much changes to it, but still nice gain. Good job!
 

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Discussion Starter #3
I will be trying a 2.5" setup also.

I had the wastegate shimmed too so it was loosing some boost. I shimmed the wastegate so the boost would not modulate.
 

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Exhaust

based on your track time and what I am seeing on your charts, its looking to me like some how, the STOCK ECU, is screwing with your boost controller.

Im not convinved that its letting you up the boost....I have a funny feeling that the car has some sort of protection hampering your output.

Still those are really nice gains, esp the torque

Cali
 

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Looks like it did help your spool up time, well..that in conjuction with the Manual boost controller that is.
Just based on the power curve compared to stock..that's what i'm guessing. probably around 500rpm sooner. As I seem to recall the SRT's only hitting ~200lb feet at about 2600ish or so where from your chart it looks like your hitting 200lb ft. at 2100rpm and your HP curve seems to hit harder about 500rpm lower than stock. which is *great* to know since I'll be stepping up to a larger turbo as well in the near future.
 

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Exhaust Depot said:
I took the car to dyno today. I did not do a stock run on the car. I have seen most guys put down 220 to the wheels.

The first run was done with no cool down of the car or no fans. I drove in, strapped it on and ran it.

First run was 219

Second run we let the car cool down and we used the fans.

228


third run we cranked the boost to 15psi. It dropped down to 13 psi after a few which is why you see the huge increase in TQ but a lower HP.

Fuel was at 11/1. If we can get it to about 12/1 it will run alot stronger. Did some one say AFC? :)


So it looks like the exhaust gave a good 8hp to the wheels which is not to bad. NExt mod is the intake :)
am i still an A&&hole for convincing you to go dyno?.... :lol: i knew you wouldnt resist....were you satisfied?
 

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Re: Exhaust

cali said:
based on your track time and what I am seeing on your charts, its looking to me like some how, the STOCK ECU, is screwing with your boost controller.

Im not convinved that its letting you up the boost....I have a funny feeling that the car has some sort of protection hampering your output.

Still those are really nice gains, esp the torque

Cali

The Mopar ECUs will fix that. 8)
 

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Re: Exhaust

mrmixitup said:
cali said:
based on your track time and what I am seeing on your charts, its looking to me like some how, the STOCK ECU, is screwing with your boost controller.

Im not convinved that its letting you up the boost....I have a funny feeling that the car has some sort of protection hampering your output.

Still those are really nice gains, esp the torque

Cali

The Mopar ECUs will fix that. 8)

Thats what I am wondering...wouldnt be better to wait until mopar releases ECU upgrades, or someone decides to crack it?
 

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Mopar knows what they are doing. They have been working with the car for months already.

You can wait until Mopar releases their ECU, then wait for a company to copy it, or possily reprogram yours to read the same.

VW 1.8T owners have already done this with their chips. There are several options available already for chips that boost the turbo significantly.

Off topic: A chipped 1.8T will give our cars a good run for the money. They dyno at about 234wtq or so with just a few mods. :p

Of course, a VW turbo on a 1.8 will only last about 3k miles putting out that much boost. (There are exceptions, of course).
 

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Discussion Starter #10
On the road I am able to run 14lbs with no problem but I never took it to redline. I dont know why it dropped some on the dyno? The car is not able to take over the boost when you are bypassing its boosting capabilities. I can crank the boost all the way up if I want to. The car sees the boost levels being higher so I think it might be backing off on the timing to play it safe.
Also, I shimmed the wastegate so its actually cracked open a little bit. I will take off the shims from the wastegate and try running it again with out the boost controller installed. I know boost will come online sooner. The reason I shimmed the wastegate was because boost would come online so fast that the wastegate arm would start modulating causing the boost to modulate before it would actually settle to the selected amount of boost displayed on the boost controller.

You can tell a big difference in the torque with the exhaust system on and it pulls alot harder on the upper rpm area. I am happy with how the car runs and feels with it on. I drove a fellow srt4 guys car and raced my own car with him driving it. He pulled 2.5-3 car lenghts on me easy. ANd it was not a slow creap.

Now to try it at the track again. :)
 

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Hey Exhaust Depot. Just so you know, AWD ENVY is a friend I work with. He's asked you several questions before. He knows a lot about turbo-charged cars and owns a 92 Mitsubishi Eclipse GSX AWD. Anyhow, I wanted to let you know that we hooked up a manual boost controller that doesn't fluctuate hardly at all. You keep talking about the need to "shim" the wastegate, but I don't believe you have to do that. I don't do that and I get quick boost to 16psi and it drops back right to 14-15psi. We made sure that the MBC has a very small pinhole in the body to keep it from spiking or fluctuating. I believe there is also another component with the turbo stuff that "bleeds" off extra boost. That could very well be what is causing you to lose boost. I believe you would normally unhook this "solenoid" thing and plug it off to avoid that bleed. Anyhow, we're still looking at it (when I get time) and we'll see what we can do.

Right now, my SRT-4 is running great at 15psi!
 

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Re: Exhaust

cali said:
Its looking to me like some how, the STOCK ECU, is screwing with your boost controller.

Im not convinved that its letting you up the boost....I have a funny feeling that the car has some sort of protection hampering your output.
If you even believe this, then you don't understand the turbo system and how it works. Please do some REAL research before you post crap like this. I don't mean to come off sounding like a dick, but I hate seeing people post crap like this when there are people trying to learn things.

The SRT-4 is a great setup... but with the "rumor mill" churning shit like "I heard" and "I saw" misconceptions, it's going to make people wade through a internet pool of crap, and further mess with the people trying to learn. If you don't KNOW then you shouldnt be posting unless you mention it is theory and present the logic behind your thoughts.

The ECU can NOT directly control the boost level by the wastegate actuator. The wastegate actuator(which decides the absolute lowest boost) is not adjustable*. In order to "UP" the boost, something(ECU, Boost Controller) needs to either bleed off air, or delay the air signal to the wastegate actuator. Typicly factory turbo systems have a BCS(Boost Control Solenoid) or some sort solenoid to bleed off extra air when the car is running good resulting in higher boost levels.

The ECU CAN pull your cars ignition spark/timing which will directly show a decrease in horsepower, but not effect the boost level. You ask, which variables help the ECU to decide what and when to mess with timing ? I'm sure is still a mystery at this point for the SRT-4(Unless the PVO engineers are sharing helpful information :lol: ).

The MAP's signal is also directly related to the cars Vacuum or Boost (hence the name "Manifold Absolute Pressure"). Most likely this is one of the main variables used to calculate the cars air/fuel mixture. The only time the MAP is going to be an issue, is when the Boost level exceeds the maximum of the MAP. At that point it will no longer register pressure and makeing anything above it's max pressure a guessing game for the ECU(Not good). This is why you see new Higher rated(2bar, 2.5bar)TIP & MAP sensors included in mopars Staged upgrades.

*some aftermarket actuators doe have and adjustable set screw on the rod, but this is only manually adjustable from under the hood. Hahn Racecraft is good example of one of these styles.
====================

Exhaust Depot:

What is your logic for shimming the wastegate actuator? That's only going to make it open the wastegate sooner thus lowering your minimum boost. I see it helping with nothing of fluctuation. Have I missed something ?
 

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Exhaust Depot said:
I took the car to dyno today. I did not do a stock run on the car. I have seen most guys put down 220 to the wheels.

The first run was done with no cool down of the car or no fans. I drove in, strapped it on and ran it.

First run was 219

Second run we let the car cool down and we used the fans.

228


third run we cranked the boost to 15psi. It dropped down to 13 psi after a few which is why you see the huge increase in TQ but a lower HP.

Fuel was at 11/1. If we can get it to about 12/1 it will run alot stronger. Did some one say AFC? :)


So it looks like the exhaust gave a good 8hp to the wheels which is not to bad. NExt mod is the intake :)
How did you control the boost from 12PSI to 15PSI? Was this your custom exhaust or is there a kit we can purchase?
 

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Discussion Starter #15
Samel whats up!?

There are different types of boost controllers. I use to have a manual boost controller back in the days. It comes with an orifice that you put in the hose. I used it on my conquest and on my TT supra. I had no boost issues with it.

The older electronic boost controllers where nothing more than a solenoid that opens up and bleeds air to the atmosphere. Its pretty much the same thing as the stock setup where it opens a solenoid to bleed air to the atmostphere so the wastegate actuator stays closed longers. YOu can get away also by using a .59 cents bleeder T. you put it inline with your WG vaccume hose and wala, it allows you to boost higher.

AWD,

The newer HKS solenoid does not work like the older solenoids where it opens up and vents air to the atmostphere. What it has is an orifice that has a modulating diameter that various in size. It closes and does not let air reach the WG. Once the HKS system sees the correct psi its set to, it opens the orrifice to alow the wastegate to open. The higher you set the boost to, the smaller the orifice is. This allows you to hit boost a whole lot sooner.

With the EVC installed and set to the stock level, boost comes on super fast. Alot faster than the than the stock one. The hole pretty much stays full closed (no manifold pressure at the WG) so the WG is fully closed. So say you are boosting 10psi (making up numbers here now), the orifice will not crack open till you hit 9psi which then causes the wastegate to open very quickly cause it sees the full 10psi in the manifold. This causes the WG to flutter pretty bad. I wish I would have installed the Blitz boost controller instead because it has a gain feature on it. It allows you to controll how soon the boost comes on line. The orifis does not open as quickly giving you a genteler increase in boost.

This is the reason why I shimmed my WG. I will put it back to stock once I experiment with it a little bit. Newbies:

The wastegate dash pot is set to 4psi. WHen the manifold pressure gets up to 4-5 psi, this pressure overcomes the 4psi spring tention in the WG dashpot and causes the WG to open and cause the exhaust to bypass the trubine wheel of the turbo and go overboard.

Now, imagine you take that vaccume line and put a t fitting in it. Now you have a calibrated leak. the bigger the T fitting, the bigger the leak. So now say your manifold is now seeing 4psi, there is only (making up numbers again) about 2psi actiong on the WG because the rest is bled off to the atmosphere. SO now once the manifold sees 10PSI, there is now about 4 psi at the WG so it now opens. You need more pressure to open the WG because your bleeding alot off. Same as a vaccum. When you go to a cheap gas station and crack the straw, you need to apply more vaccume in order for the soda (pop for you canadians eh) to come up the straw.

The only way the ECU controlls boost on a car is by controlling the solenoid that leaks boost out of the vaccum line thats connected to the wastgate.
 

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Exhaust Depot said:
Samel whats up!?

The wastegate dash pot is set to 4psi. WHen the manifold pressure gets up to 4-5 psi, this pressure overcomes the 4psi spring tention in the WG dashpot and causes the WG to open and cause the exhaust to bypass the trubine wheel of the turbo and go overboard.
The SRT-4 has a 4psi wastegate? No wonder it is having trouble regulating when it sees a sudden increase. My T-25 (or T-too small for everyone) is set at 8psi (and I have it set at 16.5psi). Hmm... Guess I'm definately going to get a bigger turbo for the SRT-4.

I used to have a EVC IV on my Talon and I noticed that the MBC helped get me boost in first gear. The EVC and stock controller never gives me much boost in first (considering I have a 10lb flywheel, I'm in 1st about the time it takes to let the clutch out ;-) Also, I had to reprogram (i.e. have it calibrate) the EVC every month or so... it didn't like changes in temperature.
 

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Exhaust Depot said:
Samel whats up!?
AWD,

The newer HKS solenoid does not work like the older solenoids where it opens up and vents air to the atmostphere. What it has is an orifice that has a modulating diameter that various in size. It closes and does not let air reach the WG. Once the HKS system sees the correct psi its set to, it opens the orrifice to alow the wastegate to open. The higher you set the boost to, the smaller the orifice is. This allows you to hit boost a whole lot sooner.

With the EVC installed and set to the stock level, boost comes on super fast. Alot faster than the than the stock one. The hole pretty much stays full closed (no manifold pressure at the WG) so the WG is fully closed. So say you are boosting 10psi (making up numbers here now), the orifice will not crack open till you hit 9psi which then causes the wastegate to open very quickly cause it sees the full 10psi in the manifold. This causes the WG to flutter pretty bad. I wish I would have installed the Blitz boost controller instead because it has a gain feature on it. It allows you to controll how soon the boost comes on line. The orifis does not open as quickly giving you a genteler increase in boost.

This is the reason why I shimmed my WG. I will put it back to stock once I experiment with it a little bit. Newbies:
I'm fully aware of how EBC's work. I owned/played with my fair share of different boost controllers. To be honest, I've never had(or heard of) a problem with a wastegate "fluttering" unless the WG actuator was set to low(but this shouldn't be the case as yours WAS still stock at the time). Spikes... yeah, Boost Creep.... yeah, flutter.... never had it. I'm not saying that it doesn't happen, but your the first case I've ever heard of "wastegate flutter". Maybe I (as well of a lot of fellow Boost Junkies) have always been lucky. :?

As you said "The hole pretty much stays full closed".... by the time your at your set boost level (say 15PSI), the hole/valve will open allowing pressure to the WG. Since the pressure is greater than the Stock WG spring setting, it pushes it open. When the Controller detects less than the set amount the valve closes, thus closing the wastegate and starts building boost. I realize all this happens very quickly.

I only see bad things happening with shimming the Wastegate, and nothing good. If you shim it to much, its going to leave the WG flapper slightly open allowing exhaust gasses to flow through the WG even under normal conditions.... and that would hinder your spoolup/topend.

Are you sure you Boost Controller/Valve assembly is working correctly ?
Did you intercept the line going directly from the compressor housing to the wastegate, or did you get your pressure source somewhere else ?



Just trying to help.....
 

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Discussion Starter #19
IM guessing its a 4 psi spring because when i turn off the EVC. I only get 4psi. The EVC is opening both solenoids to full open so you get full pressure on the WG arm.
 

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Discussion Starter #20
AWD,

I am not questioning your knowledge of Turbo 101. Im sure you know your stuff. The turbo setup on the SRT-4 is different than anything else I have seen. The actual wastgate is part of the manifold. The turbine housing is very small and it spools super fast. I know if I instal a bleeder T I would not get this problem.
This is the first time I ever had a boost flutter on me also. Its anoying too when your driving the car and feel the power level oscillate.

I did install the controller right though. Give me an email and ill show you pics of the manifold . I toook good pics of it.


[email protected]
 
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