My Mom wants her SRT4 to go faster for Christmas.
 

Is there anything I can do sub $100 to make it somewhat faster? The turbo isn't externally regulated is it? (Meaning, can I wrench on it and jack up the boost a couple lbs?)

Replace the resonators with pipe maybe? Cheap cold air intake?

To make it seem faster do an intake. She will hear the turbo more and it will sound quicker. The turbo is internally regulated so that is a no go. You can do a down pipe, but you might get her in trouble. I would say an intake is your best bet at that price:thumbs_up:

Your Mom drives a SRT-4? That's pretty badass.

From what I know from helping a buddy with his SRT-4, a wastegate actuator is a good, cheap upgrade. Those go for around $160. Holds stock boost without tapering down like the stock one does. That with a manual boost controller, you can turn the boost up. I think the max on the stock fuel system is around 17psi.

I don't own one, so I might be completely wrong, but that was what I remember from helping him.

Another thing that really helped was motor mounts.

You should be able to go to PepBoyz and get some stickers. They are good for about 5hp and 5TQ each I think. At least that is what some dude told me after he watched Fast and Furious and that movie is like a documentary or something! :jester:

Yes, and portholes. LOL

:boggled::boggled::boggled::boggled::boggled: :boggled:

I've been looking at those manual boost controllers. Looks like you can plug off the ecm controlled solenoid vacuum ports and hook the... wastegate? up to the boost controller, which basically regulates manifold vacuum.

I'd want to get confirmation that this can actually be done though, hopefully blacknboostn will chime in. I know you can do it electronically too but that's out of the price range.



Otherwise, intake it is. I've also been thinking about replacing the resonators with straight pipe. Not sure if it would smog though. kdracer73?

Manual boost controllers are pretty popular on SRT-4s. I don't really know how safe they are, considering the whole part throttle, full boost issue.

i dont recomend a manual boost controller. Issues can arise and no i am pretty sure you wont pass smog straight piped. At the price you are looking the only thing really is intake, unless a corner is cut and you risk possible problems with cheap upgrades like manual boost controllers.

Wastegate Actuator $100

From what I have seen this is actually a pretty good product to install on the srt-4. The car is notorious for boost loss and this solves it.

I have a MBC Ill let go for cheap. I forget what kind it is, but it was on my buddies old Evo8.

That kind of doesn't make sense to me. If the wastegate doesn't want to hold 14lbs of boost, it's not going to hold 14lbs regardless of the rpm right?

I thought the reason srts dropped in boost at high rpm was because the turbo couldn't keep up with the engine's breathing demands??? (Meaning, above 5K the engine wants to suck more air than the turbo can deliver creating 14lbs of backpressure.)

Damian, for my car I'd buy it off you, but for a Christmas present it needs to be grease free and wrapped in new plastic. Thanks though.

From what I understand, it starts opening at 4psi, and the ECU tries to control boost by bleeding pressure away from the wastegate. The problem with a bleed type boost control is that even at maximum boost control solenoid duty cycle (bleeding as much boost pressure away from the wastegate as possible) you are still limited by the maximum that the wastegate spring can accept.

At high RPM, the bleed system cannot keep up with a full spooled turbo pushing pressure into the boost control system, and the pressure ultimately shows up at the wastegate actuator spring as the 4 PSI of pressure needed to open the wastegate.

Understandable. I got it cause I was going to go TT on my Eclipse, well kid came along and changed that plan.

Any changes before cat are a no-no as far as smog rules go.Damn tree huggers :hippy:

The resonator is after the cat I'm pretty sure. There's no muffler from the factory on this car. Just downpipe/ flexpipe, then cat, then resonator, then y pipe out to the chrome tips.

So still a no go if I replaced it?

After cat wont matter:thumbs_up:

I think Blacknboostn removed his resonators and the pigs have hassled him, not that a pig is going to hassle your mom, but... it is pretty loud though.

While I've got you in here, we removed my buddy's muffler on his Ranger and replaced it with a pipe that shoots out the side. Can he smog like that?

As long as the cat is in OE spot, should not matter.

I'm still leaning towards the manual boost controller, my Mom shifts like a Mom. She's not running this thing through the gears shifting just before the rev limiter. She's more of a short shifting, full throttle at mid rpm weaving in and out of traffic sort of driver. I think she'd like the max boost at mid rpm. she might not ever even feel the extra 2lbs past 5K.

As far as intake, I found a bunch on E-Bay for less than $100, but none that are CARB legal. I don't want to have to swap this shit out every two years.

Yep if you went with intake definitely only recommend carb legal like a k & n
I am sure your mom will be happy with whatever you get her

hmmm i wonder why i didn't see this thread earlier!!!

look up the spring mod, it works but i'm not sure if it's something you wanna do on ur moms car lol. There are quite a few ghetto mods you can do... your best bet is probably the kinetic wga. it's adjustable and fairly cheap. www.modernperformance.com should have one. don't boost more than 17lbs.

I got pulled over cause my exhaust was too loud. Damn neons.

Intake would also be a good bet, but you have to deal with one thats carb legal. www.srtforums.com/forums/f365 is southern cali FS forum. Look there. WGA will be best bang for the buck though. just don't go over 17 lbs.

it was already stated so i'm going to confirm it. our pcm bleeds boost. it sucks. i spike 15 lbs or so and bleed to about 12 or 13 through the rpms. once i go with an AGP wga or even external waste gate, or take it off pcm controlled boost it'll hold. need a way to tune though or its not worth it.

look through the FS threads.

good luck.

for the record Leedom, it was a 3in catless downpipe mated to a 2.5 inch Borla exhaust with a single resonator and NO mufflers... I don't blame them. lol

Boostn, I gave my mom all of the options last night and she actually wants the straight pipe. I think she heard "louder" and got excited. Which I really didn't anticipate, but it's prob the cheapest mod.

So yeah, if I replace the resonator with a pipe and keep the rest of the exhaust stock, and same diameter, how loud will it be? As loud as your car? I kind of doubt it because 3" pipes tend to have a real loud, high note, like... my car. Maybe I should listen to your car sometime before Christmas.

lol... mine with STOCK o2 and STOCK dp WITH cat and the Borla db'd at 119... fml. lol i don't have any idea how loud it was with no cat. lol if i make it to the meet on saturday u can hear it then lol. she can probably get away with straight pipes, maybe you should weld her up a 2.25in (stock piping diameter) side exit or dump... that'd be sick :)

why dont u just get a 3 foot section of 2.25 piping, have someone mandrel bend the tip to angle down and to the side and expand it enough to slip over the tip of the downpipe? a custom hanger and ur in business for a nasty sounding dump!

finish with the zip tie rolled bumper mod and ur dandy!

Blackboostn, would you recommend a MBC for the SRT-4? I have very little experience with SRT-4 other than helping a friend with his. From my knowledge of tuning Subies, MBC are not recommended because of part throttle, full boost conditions, causing lean running during open loop/closed loop transition. I know DSM guys use them all the time, but in conjunction with some sort of fuel controller.

I wouldn't really recommend it unless ur on an external wastegate or big turbo... an waste gate actuator would do just fine. i ran a s2 wga for a while and spike 18 and held 16 and that worked just fine lol. I actually plan and staying with my internal wga setup for most of my goal. should be able to hit 350whp on a ported stock turbo and methanol using an aftermarket wga.

imo they just aren't worth it till you hit the big numbers.

You don't still have your s2 wga do you? In case I can talk her into it, I might buy it off of you.

Is the resonator in line with a straight section of exhaust? I was planning to replace it with a straight piece of pipe and just clamp it with female sections, in case she ever wants the resonator back on.

I won't be able to make it this Sat. Last final is on Mon, I'll be studying 16 hours a day. As soon as I stop procrastinating here actually. :barf:

I do still have it, but to be honest it wasn't worth the investment. That's why I'm on stock wga right now. Needed 3bar sensors in order for the pcm to read the correct boost levels, also without fuel management or wideband its impossible to know if ur running too lean or not. It just wasn't a safe option in my case so I took it off.

I MIGHT be gettin rid of a borla catback pretty soon tho... Maybe that's an option

Yes the resinators are in line with a straight section, it should be pretty easy with the right tools to take that section out lol

I have a wideband, you should have called me. Could have hooked it up in 10 mins, taken a drive and let you know what was going on.

How much do you want for the wga? And how hard was it to put on? Did you need to pull the turbo off? And could you feel a difference with the extra boost?

Didn't know u had one

On the stock fuel system the s2 is just too much of a pain, although it held boost much better it cut fuel under wide open throttle after a while. That's why I took it off

If u really want it I'll sell it for 35.

Easy to install, remove upper heat shield, remove two bolts and a cotter pin and remove then reverse to reinstall.

Cut fuel? What do you mean? How long were you WOT?

fuel injectors probably cut out for a second to save the motor from detonation, aka "fuel cut."

Boostn, how long were you WOT before this happened? I don't see my mom on the gas in 4th gear at 120mph and climbing.

Basically in any gear, and it would happen with boost spike (these cars spool very quick) at any rpms. It held good for a while and I didn't have any issues, but then I started throwing and getting fuel cut aka spark cut. Imo if ur not gonna be s2 don't run it its not worth it!!