buzzelli

K my buddy has just bought an SRt4 and he was wondering what the maximum amount of boost he could run on the stock motor safely, as well what are the best upgrades to begin with the car to get a bit more power. He also told me that after driving it and ripping around the boost gauge displayed 13psi when the delaership said maximum boost should be eight and nothign has been upgraded to the motor. Why did this happen and how can he do it again ?

VWJettaMK2

I think 13-14 is stock for 03 SRT4. I think to run more you would have to do some kind of upgrade weather it be injectors, bigger intercooler, exhaust/downpipe, etc.

On stock everything I wouldnt take it past 16psi because at that point you'd lean out the motor..

Im not a pro at SRT4's but thats just my thoughts and opinions..

Also I think newer SRT4's(04 and up) run a bit more boost..Not 100% sure

buzzelli

okay thanks for the help i'll let him kno

shadydvh

Well you can do it safely at about 19 PSI spike and hold about 16 PSI to red line, but then the computer starts pulling timming, so you need a map Clamp

amoeba

Here's some suggestions for more power, and also an answer to the boost question you have! And by-the-by....peak boost at 13psi is right, but read on!

With all the parts that are available for the 2003-2005 Dodge SRT-4, understand that it can be hard to decide on what parts to purchase to make more power.

3 general plans for making more power. Each plan is tailored for people with different needs, noise/sound tolerances, and maintenance.

Keep in mind when your reading this, that all of the horsepower numbers are power at the wheels. NOT engine hp, but power at the wheels. The factory SRT-4 is rated at 215 hp for 2003's, and 230 hp for 2004-2005's. HOWEVER, Its well known that Mopar underrated the SRT-4 because the factory SRT-4's would dyno at 225-235 hp at the wheels bone stock. With most cars having a loss of 13-15% of power between the engine and the wheels its impossible for a car to have more power at the wheels than it has at the engine!

First up is the bolt on plan. This place utilizes the factory turbo, and is rated for 250-295 hp at the wheels. Pros- You can buy piece by piece as your budget allows Cons- Youve got to be careful to monitor boost levels

Second is the exclusvely Mopar plan. This plan utilizes the factory turbo, and is rated for 250- Pros- Care free, very well thought out performance increases. Smooth power build up. Cons- Higher costs than bolt on plan, cannot make as much peak power as bolt on plan.

Third is larger turbo plan Pros- Its time to make some serious power. Cons- Higher costs, time for a new clutch, and its very hard to keep your foot out of the throttle!

BOLT ON PLAN

You start with a intake system. Most intakes we offer will give another 7-10 hp or so. Second, an exhaust. Once you remove the intake and exhaust restriction it will allow the turbo to spool up faster. Recommend you use a 3 inch full downpipe and exhaust. Now its time to increase the boost. You can't just put a boost controller onto your factory SRT-4 and expect boost to increase steadily, because the factory wastegate is weak, and wont hold boost.
So, you need to first replace your factory wastegate actuator with a stronger actuator like the AGP or Kinetic wastegate actuator. After you replace the wastegate actuator with a AGP or Kinetic, you can increase the boost that way, and if you'd like to increase the boost further, you can use a boost controller.
If you want to increase the boost past 16 psi, you'll get a check engine code if you don't have a stage 1. Therefore, to richen the fuel mixture, and eliminate any possible check engine codes, we highly recommend you get a stage 1 pcm from Mopar. To further increase your power, a larger intercooler to cool down the heated, compressed air from the turbo.

HP levels Stock 225-235 hp

Intake, exhaust 250 hp intake, exhaust, stage 1 260 hp intake, exhaust, stage 1, boost controller 270-280 hp intake, exhaust, stage 1, boost controller, intercooler 290-295 hp

Highly recommend you install new motor mounts like the AGP motor mounts, and also recommend colder range NGK spark plugs for any SRT-4 thats driven hard!

MOPAR PLAN

For those of you who are concerned about reliability, who dont want to
do much hands on tuning/work or are concerned about noise, the following recommendations.
HP levels Stock 225-235 hp
Mopar stage 2 260-270 hp Mopar stage 2 with toys (with race fuel, on high octane mode) 275-280 hp.

Want to make even more power, but are concerned about noise levels, or water ingestion from a cold air intake? The Injen intake is a short ram intake that will provide good power, and is short enough to not have problems with ingesting water. The Mopar exhaust increases the noise level by about 10-12% and provides a nice power increase.
You can make even more power by using a new wastegate actuator, along with a intercooler, both are optional. You can follow these plans, or modify them to your liking. We have created this plan to give you a better understanding of what power levels can be expected. I highly recommend you install new motor mounts like the AGP motor mounts, and also recommend colder range NGK spark plugs for any SRT-4 thats driven hard!

BIG TURBO PLAN

Need more than 300 wheel horsepower, this is your only choice. The factory turbo just cant flow anymore air, and runs out of efficiency past 19 psi, or around 300 hp at the wheels.
At this point, you have two options. 1) Use a Mopar stage 3 turbo 2) Use a larger turbo, and manifold like the Hahn Racecraft kits.
With option 1, the Mopar stage 3 turbo kits, there is a Mopar stage 3 kit without toys, and Mopar stage 3 kit WITH toys. The base kit makes 315-330 hp at the wheels, and the kit with toys, with race gas and high octane mode can make 360-375 hp at the wheels.
With option 2, the Hahn Racecraft 16G kit can make 320+ hp. The 20G can make 360-380 hp or more. If you choose the Hahn Racecraft turbo kit without the port fueler, youll need to create your own fuel system, wether it be the AGP return line kit with RC injectors, or the Apexi SAFC with RC fuel injectors. Or, you could use the AEM EMS for complete tuning of timing, and fuel needs.
Of course, with either option, if you have other modifications like intake, 3 inch exhaust, intercooler, you can make even more power. Or, if you want to make even more power, you can add cams, and port the head for additional air flow. Tuning for fuel will make the difference here!
Keep in mind, that once you make over 300 hp, your factory clutch will not hold up, and you should replace your clutch to hold all the power your car will now be making.
Better motor mounts, like the AGP motor mounts, and NGK iridium plugs at this stage, are not an option, they are a MUST.

Have fun...I hope this helps!