I haven't even picked up an SRT yet, but am actively looking for a nice, clean SRT roadster, and being a motorhead, I'm already trying to envision the engine mods

I assume the biggest bang for the buck is the supercharger pully swap to increase boost, ECU tuning to reprogram for the pully swap and fine tune the computer, swap the air cleaners for K&N's for better breathing and possibly exhaust ugrade to up the breathing as well, is that basically the general consensus ?

How easy (how costly is it may be a better way to ask) is it to squeeze 400HP from the SRT engine ?

Thanks,
Brian

 

Short answer:
About $1100 gets you 400+ crank hp.

Long answer:
The SRT-6 was advertised at 330 crank hp, but actually has 350 crank hp - bone stock. It was a Chrysler / Mercedes marketing thing.

Most aftermarket or even DIY cold air intakes will get you about 25 whp (about 30 crank hp). There's a bunch of them available, but most perform so similar, its largely a matter of personal preference. The NeedsWings CAI costs $450.

A supercharger pulley will get you another 35 whp (about 40 crank hp). The only supercharger pulley available is from Code3 and costs $650. You can also go with a larger crank pulley. There are a couple manufacturers, and they generally run about $1000. The 178mm crank pulley is supposed to be power equivalent to the Code3 SC pulley. Larger crank pulleys are also available.

A custom ECU tune varies on how much power it will get you. Some folks here have seen increases of 20 whp (about 24 crank hp). A custom ECU tune can cost from $500 on up, depending on where you get it.

Soon to be available are aftermarket intake plenums. The prototypes made 37 additional whp (about 44 crank hp). They should be available soon from NeedWings. Pricing hasn't been announced yet, but will probably be close to $1000.

So if you went with all of that, you'd have approximately:
Stock:__350
CAI:____+30
Pulley:_+40
ECU:____+24
Plenums:+44
===========
Total:__488 crank hp (about 390 whp) for $2600

Of course, there's a few other things you should do to keep all that power from being sapped by heat. Such as a new coolant pump ($150), separate your engine coolant from the intake coolant (custom), larger heat enchanger (may or may not actually help), phenolic spacers (about $100), and perhaps modding the electronics controlling the coolant pump and fans.

And there's more radical - or should I say less popular - mods such as meth or alcohol injection, conversion to E85 fuel, and many others.

 

Tom thanks, that's exactly what I was interested in knowing.

It looks like the CAI and the pulley are the biggest bang for the buck, 70HP for under $1000, can't beat that.

Do all the CAI's basically look like this:

http://cgi.ebay.com/ebaymotors/ws/eB...m=230275797092

I've been reading SRT exhaust mod threads here, and that looks to be a bit more pricey and not as much as a performance increase I'd think it would for the money.

Thanks again,
Brian

 

No, all the CAI do not.. a lot of "CAI" have their intake filters right next to the engine bay.. in my opinion what's the point as it's sucking in hot air directly from the engine?

I may be biased, but I believe the CAI from Needswings is the best you can buy for your SRT-6. I have one on my coupe and I can't say enough things about it.. it's amazing!

This is a very good pic of the layout.. it's a coupe but the srt-6 isn't that different at all..

Hopefully Gary (Valkryderguy) doesn't mind me using his car..!

 

CAI
Here is a link to modifications that Steve Hellums did to his stock CAI - he removed the choke points at the radiator shroud, added a SL55 Y-Pipe at the throttle body, dropped in some K&N filters that helped him get to 12.5X second ¼ mile runs that he has listed on http://www.dragtimes.com (12.51 ET)

https://www.crossfireforum.org/forum/showthread.php?t=19780

https://www.crossfireforum.org/forum/showthread.php?t=19969

I believe Steve's SL55 “Y” addition and the K&N filters was around $125. Pretty simple DIY mod and the stock plastic components stay pretty cool under the hood. Plus you pull cold air thru two 3” snorkels

The other 3” metal pipe CAI’s pull from only one side – a few members have had to heat wrap their metal intake to try and reduce intake temps.

You also have the option of the Full SL55 AMG Intake – this intake makes 500HP power for the AMG V8 Supercharged engine. Just fits in our engine and runs about $350 for a full setup and it’s easy to install. I stuck with the Stock air filter that AMG provided with the airboxes. But you could drop in K&N’s.

PULLEY
If you decide to save money by doing Steve’s Simple, effective mod – and your looking to go big – The 185mm Crank Pulley provides the most boost and it's recommended that you get an ECU tune to match. You can get both the Pulley and the Tune at www.letmotorsports.com They can also provide you with smaller pulley’s (178 and 181) if you don’t want to go to big… I bet you can get a Tune and Pulley Combo for around $1500 +/-

MikeR runs the SL55 intake, 181 Pulley and ECU tune from LET and here is a link to his very respectable ¼ time results (12.56 ET) with his set up. https://www.crossfireforum.org/forum/showthread.php?t=26721

IC Pump and Heat Exchanger
Definatly something worth doing ($450) every little drop in IAT helps performance. A Few of us have separated the Intercooler fron the Engine Coolant with great results. You can do this mod for around ($160) but you can hold off a while on this mod if needed

EXHAUST
Not sure of any exhaust that’s actually made horsepower. Many have gone with the resonator delete just to improve the note coming out the pipe.
Price on this can be any ware depending on materials and labor. Headers seem to be a pipe dream and have yet to see a proven set on a SRT6.

Hope this helps – you can click the mods below my signature – but there are many options available to you

Here's a pic of MikeR's SL55 AMG setup

 

Hey nox1s, yep that makes a lot of sense. Does anyone make one that actually funnels or scoops the air into the intake (like a ram air setup) ?

 

Thanks Brian, this is great info. I like the DIY CAI.

I can see I'm going to be spending a lot of time on this forum, and tweaking the SRT once I land one

 

My exhaust made 15rwhp and 20rwtq, and saved 23 lbs. I expect even higher gains from my next exhaust design.

 

44+ hp for intake plenums?

 

Sorry man - I figured he was askin' about available bolt-on mods..

 

That's using Rob's dyno numbers of +37 whp plus ~20% due to drivetrain loss yields ~44 crank hp. (Actually 46.25 but I was being conservative) Keep in mind my original post is talking crank hp not wheel hp, because that's what I thought the original posted was talking about (crank not wheel). Getting an SRT-6 to 400+ whp is a bigger challenge. Not impossible, just more money!