400 whp

[c_brks]

i got a 05 srt and it has a stage one kit in it already. i was wondering what would be the best way and the cheapist way to accomplish 400whp

[R/Tony]

Not with the stock turbo...

The cheapest way is nitro.

[c_brks]

yeah i know i was planning on upgrading the turbo computer injectors and fuel pump but i want to know whats the best combination

[blackbird]

There is no "best" way to achieve that power and none of them will be cheap. First off the stock turbo is a member of the small MHI (Mitsubishi Heavy Industries) TD04 family and cannot physically support the air flow required for those power levels. You can rebuild the turbo and install a bigger compressor wheel, port and rework some of the exhaust manifold, but due to the exhaust housing being cast integral with the manifold you're stuck with the small TD04 exhaust turbine wheel and small 6cm² housing which limits flow potential. About all you can do to help the exhaust side is clip the turbine wheel but that will only get you so far (figure lower 300 range to maybe mid-300 whp if you push a modified stock turbo to the ragged edge).

The Mopar Performance Stage 3 kit is a nice bolt-on, plug-and-play kit that looks close to stock and has nice engineering behind it but will probably get you around 300 to the wheels on pump premium and mid-300's on race gas in high octane mode. With other modifications you can improve those numbers and it's not unheard of to see over 400 whp with S3-based turbo's. But to modify the turbo like a lot of people have been doing recently in order make those much higher power numbers will require a lot of additional modifications to the car which negates the advantage of being a bolt-on kit (although it will still look similar to a stock car to an untrained eye).

There are many other aftermarket turbo kits on the market that use many different types of turbochargers. The 50-trim T3/T04E "hybrid" is a very popular upgrade that is well matched to the engine and can support the power levels you're looking for along with a lot of other turbo's such as the GT3071R, the GT2871R, etc. But you'll also need a lot of other modifications just to be able to run an aftermarket turbo. You'll need a full turbo kit that includes a replacement exhaust manifold along with the O2 housing to connect to the down pipe. And that's just the start. To be able to make the power you want figure in larger fuel injectors, fuel pump, maybe a return fuel line kit with adjustable fuel pressure regulator, different intake to mate up to the bigger turbo, a different charge pipe with a BOV flange installed, the external BOV itself, bigger exhaust system and better flowing downpipe, various lines and fittings, possibly a better intercooler, boost controller, and we haven't even mentioned tuning. A few years ago the SRT-4 used to be limited to piggyback fuel controllers like the Apexi S-AFC, Greddy eManage, and TurboXS DTEC where you mechanically dump in more fuel (via injectors and return line kit/morefuel pressure) and trick the MAP sensor signal going to the PCM in order to fine-tune fueling. Altering the MAP signal like that can have some nasty side affects on ignition timing but it has and will work. We now have stand-alone engine control computers you can plug in to control fuel/timing and recently SCT Flash (which is big with the Ford/Mustang crowd) came out with software to reprogram or "reflash" the stock computer. If you want a reliable 400 whp you'll probably want to skip the piggyback and go with one of those alternate tuning methods but no matter what way you decide to go there's going to be a lot of cost involved in tuning the car if you don't want to do it yourself. Which brings up another point in that you're also going to need some gauges like a wideband air/fuel and other logging equipment to monitor things like OBD-II data (timing, knock, etc.) no matter if you have someone tune the car for you (since you'll still want to monitor and make sure it's running correctly under different real-world operating conditions) and would definitely be required if you try to tune it yourself.

To step back for a second, is there any reason you're shooting for 400 whp? The reason I ask is that I've seen too many people get carried away in wanting peak "dyno queen" numbers or because they want to break some goal "just because" they can do it. There's nothing wrong with that but I'd advise most people to look at what they want to accomplish with the car. If they just want a daily driver with a great power band the stock turbo or even the Mopar Stage 3 might be enough with a few carefully selected modifications. It might not produce those super high peak numbers but the car can still have enough power to the ground to be fun to drive and crush many, many other cars out on the street. And going a lot higher than what S3 can support is going to be hard to utilize on the street. If you do a lot of drag racing or other road course or autocross type racing then you need to look at it backwards and start with your racing goals and then match the turbo to the engine to create the power curve required to meet your goals. Keep in mind I'm referring to power curve rather than peak whp numbers and being able to utilize what you're putting down. Brings up a variation on an old saying. Q: What's faster in the quarter mile, a 600 rwhp Supra or a 1000 rwhp Supra. A: Neither. They're both 10 second cars.
Remember it's still going to be a front drive Neon…

Eric H.

[c_brks]

well thanks for that very long but yet informative reply. what i would like to get out of the car is to be able to hit low 12's high 11's in the quarter. i had planned on either running a mopar performance computer or running a megs squirt system on it. with the squirt i got a guy that will do all the tuning i need. i was planning on bigger injectors and fuel pump with a return system new turbo computer. as far ass manifolds go i will custom makes those myself

[JamesL]

Check back with us in the near future. Mopar Stage 2 + 50 trim Hybrid (or possibly s3 turbo) + our new SCT 3bar tune + FMIC + manifold work apprx. + 93 Octane = 400WHP.

Quote:

Originally Posted by c_brks well thanks for that very long but yet informative reply. what i would like to get out of the car is to be able to hit low 12's high 11's in the quarter. i had planned on either running a mopar performance computer or running a megs squirt system on it. with the squirt i got a guy that will do all the tuning i need. i was planning on bigger injectors and fuel pump with a return system new turbo computer. as far ass manifolds go i will custom makes those myself

[c_brks]

ok whats the cost on that stuff

[JamesL]

Well we are still putting this package together so a lot of it depends on any custom fab work needed.. You can't hold me to this as it may be higher or lower but this is a rough estimate:

Stage 2 = 979
50trim Hybrid, lines, exhaust, manifold, etc. = 1500
SCT Tune = 600 or SCT Dyno Tune = 775
FMIC = 299
Labor = Our parts 65*14, Your parts 75*14

Again, until we've done it, I'm not offering and this is a rough estimate. We expect to have done in the very near future.

Quote:

Originally Posted by c_brks ok whats the cost on that stuff

[c_brks]

how much cheaper would it be if i didnt buy the manifold? just a guess

[JamesL]

Quote:

Originally Posted by c_brks how much cheaper would it be if i didnt buy the manifold? just a guess

Well if your going to run a 50 trim hybrid, you need a manifold. Do you have your own? I think the manifolds sell for about 250.00

[blackbird]

Quote:

Originally Posted by JamesL Stage 2 = 979 50trim Hybrid, lines, exhaust, manifold, etc. = 1500 SCT Tune = 600 or SCT Dyno Tune = 775 FMIC = 299 Labor = Our parts 65*14, Your parts 75*14

If you were going to go that route you'd be better off starting with the stock computer than with buying a Stage 2 kit. With the SCT reflash you would be wiping out the "Stage" programming anyways and you can buy the 3 bar MAP and TIP sensors separately as well as the Stage 2/3 injectors. Speaking of injectors there are also aftermarket drop-in injectors like 650 cc/min units from a few sources that cost the same or less as the Mopar units and flow more (remember that Stage 2/3 injectors are rated at 682 cc/min but that's at 58 psi and the aftermarket drop-in injectors are rated at 43.5 psi and usually use a different test solvent than Mopar used and would flow north of 750 cc/min if used on a stock fuel system pressure car). Also the Stage 2/3 injectors would require increasing fuel pressure via a return line kit to support 400 whp and even if you did that they will still be pushed right up to the ragged edge to support 400 whp. Along with the injectors figure in the cost of a Walbro 255 fuel pump as the stock unit trying to push that much fuel on a return or returnless system doesn't work well at supporting those power levels (the 180 LPH Walbro included in the Mopar Stage 3 kit even has issues trying to supply adequate volume at the higher pressure that system runs at).

There are also quite a few other random items that many people fail to include in planning. Figure in the cost of an aftermarket intake required to mate up to the larger T04B/T04E compressor housing as well as a BOV and associated charge pipe adapter. You'd also either need to modify the compressor outlet on the turbocharger or supply a modification kit or replacement charge pipe to mate up to the bigger turbo. The factory boost control solenoid may or may not turn out to work within the limits of the SCT reprogramming capabilities so that opens up the chance you might need either an upgraded solenoid wired into the factory harness or possibly have to use a different manual or electronic boost controller.

If you're basing a turbo kit on one of the aftermarket cast, log-style manifold designs you can probably do a 50-trim, manifold, discharge adapter/O2 housing, external wastegate, fittings/lines/hardware/gaskets for about that price but the customer will also need to figure in the cost of a larger aftermarket downpipe and cat-back exhaust system if they have not already upgraded that. After the stock turbine housing and TD04 turbine itself along with the O2 housing the stock cat is the next biggest exhaust restrictions on the SRT-4 and will choke a big turbo. Depending on the kit and overall design you might need to figure in the cost of a dump tube or recirculating it into the exhaust stream. And even with a good dyno developed and street tested tune the customer should still consider adding a wideband A/F gauge and scan gauge/tool to monitor for knock and how the car is running if they are trying to push a lot of power on pump premium. Not to mention possible engine modifications such as removing the balance shafts so the plastic guide tensioner does not break and cause havoc (as well as freeing up some power). At those power levels the stock Gerotor oil pump has been known to cause some issues if the engine is extremely fast revving when building boost. And if the customer is on a stock clutch they need to figure in that cost as well since the stock Sachs unit will not hold up very well once you start pushing a lot more torque.

It is possible for someone to piece together a larger turbo kit but to be able to fully utilize it safely and efficiently you plan on a lot of other small upgrades. The turbo kit itself is only going to be one part of the overall cost. You can build a system on the cheap and can then either a.) not push it to the desired potential (i.e. keep boost down until everything else is upgraded), or b.) push it hard and expect a higher chance of running into reliability/durability issues.

Eric H.

[JamesL]

All very good points to consider when trying to estimate the cost of an upgrade like this

[bpsrt4]

I'll just say it is fun sometimes, other times...not so much.

I just added everything up and...

I'm over $5000, and a lot of my parts were bought used, and it was tuned by me

This doesn't take into account all the suspension and traction mods to try and help put the power down to the ground, unsuccessfully I might add

There are cheaper ways of doing things, and there are more expensive ways.

You could probably save over $1000-$2000 easily if you wanted

[c_brks]

as far as the manifolds and intake stuff all tha i can make myself so theres no need to buy the stuff. but from the sounds of what your saying with thte computer i would be better off having it reflashed then buying aftermarket from moppar.for the turbo i was thinking of using a t3/t4 that my buddy has that just needs a re build so theres some money saved considering he will give it to me so all i need is a rebuild kit. for the fuel pump i was planning on buying a 255 walboro and for injectors i have seen 750cc rc injectors buy it now going for about $350 on ebay. as far as controlling the boost i was thinking of just getting a manual boost controller for now unless i end up putting a megasquirt kit on it and if im not mistaken the mega squirt will control the boost if you set it up right.

[crazymadbastard]

Quote:

Originally Posted by bpsrt4 I'll just say it is fun sometimes, other times...not so much. I just added everything up and... I'm over $5000, and a lot of my parts were bought used, and it was tuned by me This doesn't take into account all the suspension and traction mods to try and help put the power down to the ground, unsuccessfully I might add There are cheaper ways of doing things, and there are more expensive ways. You could probably save over $1000-$2000 easily if you wanted

Hey Brian,
You put down some really good numbers on dyno day, another one is coming, wanna go for more?

I think you are saying that you can do it 2 ways:

A buy proven kit for $3k
or DIY for 5k