Top 5 mods to add HP
 

Hi I am new to the forum, and love all the cars I have seen on here. simply amazing. I am looking at purchasing a 986, but want to know what I could do to add some HP, as it is my understanding that the base models are not the fastest car on the block. Let me know what you guys think? thanks

1. Buy the S
2. supercharge
3. intake
4. headers
5. muffler
6. decrease weight
7. the blade

what year and model?

LOL. Almost as good a boost as the tornado.

I would encourage you to first work on the suspension, then see if you need any more HP, its pretty amazing what some folks can do with their Boxsters with stock engines...

Ed

:D

There aren't many more than 5 things to do to increase HP short of engine conversion or forced induction. If your very first thought after purchase is dramatically increasing HP than this may not be the car for you. You can achieve some noticeable gains by:
1) cold air intake
2) some form of modified exhaust (be wary of side effects such as resonance)
3) ECU tuning
Pretty standard recipe.

I have gained just as much or more pleasure from the short shifter and the suspension upgrades. I have also found that the potential in these cars is further realized the better driver you become. I have had better drivers race my car and I am humbled. All the HP in the world wouldn't help me keep up with these guys.
Lots of luck to you.

Tripbox, work on becoming a better driver, and use the HP the Boxster already has.

I am learning every time I take mine out. Learned a ton today on the race track.

If you havnt bought a box yet, and your already thinking about HP upgrades, you better get the S. 2nd, if you really want more hp, spend the money and get a 987 S, its the easiest way to get hp out of your box. Many mods give very little hp, some exhaust mods are known to actually decrease hp.

definitely a wrong car for power increase, other than FI.

work on suspension, short shifter, loosing weight, and it will be MUCh better car to drive.

haha

can't believe nobody mentioned the 996 engine swap. Not exactly bolt on, but close!

One only needs one sizeable mod to make one's ride really fast.

Trade in the boxster for a Z06.

Our cars really aren't designed for straight-line performance.

I've been salivating for a TT or a SC kit for my 2.5 for three years now, but when I drive it hard on country twisties I realize I simply do not need more power. Putzing around from light to light in town I always feel underpowered.

So I just stopped putzing around town and I'm feeling much better about my NA 2.5. It actually has tons of power for what it was designed to do.

The guys in the S's behind me on the Tail of the Dragon trip said I was every bit as quick as they were and no easier to keep up with than other boxsters with 3.2's and 3.4's in them.

I say add strut tower braces and lowering springs (and new struts if you the one you buy is over 60k mileage) and you'll be amazed at how well the car will perform around corners, where it was designed to be used.

I totally agree with Randall. I had my 2.5 up in the mountains last weekend and had a motorcycle guy behind me for about 15 miles. At an opportune stopping point he came up to me and said he couldn't believe the speeds I was negotiating the turns and twisty roads. The power band on these older Boxsters is still quite amazing and the handling is why we drive this car. I just turned 23,000 miles and this thing is bullet proof so far. (except for the roof cables!) Seems the deal with a 2.5 is RPM management, that's why it's so much fun!

HI, I bought the car for it's curves and the ones up ahead :matchup:

Lower strut brace is one mod I'd recommend ;)

I have a 99 Box and I added the powerflow cold air intake and power intake plenum (available from ************************************************************) this winter I plan on chipping it, updating the suspension and cooling system (GT3 center rad and bumper) along with the below that I'm wondering if anyone has done.

Has anyone added any of the following:
Adjustable fuel pressure regulator?
Aux Oil cooler & stat?
Silicon hoses (Samco)?

Since I added the two above mods I've been experiencing some cooling system issues so I've been doing some research trying to find the root cause and am looking for some feedback. One of the interesting things I found was when increasing HP the fuel pressure regulator needs to keep up, if it doesn't the engine runs slightly lean causing the engine to heat up more than normal, in the event of a failed or failing FPR this is definately the cause along with poor fuel economy, sluggish throttle response etc. So, that got me thinking that if the engine is going to run hotter than normal during normal conditions when I'm really leaning on her she's going to heat higher than normal.

I know that Porsche engineers will have a safety factor considered when designing the cooling system but given age that factor decreases and plastic/rubber breaks down. Higher heat also equals higher pressure which I think may be the reason why my car will puke coolant out after a hard drive.

I'm rambling a bit but I'm looking for some feedback, one thing I did notice was a lot of people here are having problems with their cooling system and I'm wondering what the probability that it's performance upgrades that are the root cause.

If you are concerned with HP and straight line acceleration you bought the wrong car.
These cars accelerate plenty fast, and handle better than most other high HP cars. The only cheap HP increase is to desnorkle, it is a proven 2+ HP.

linkjones,
If you are having overheat problems and your car is dumping coolant you have cooling system problems... Bad t-stat, clogged radiators, bad coolant cap etc. Others have replaced their motors with a 3.4 996 without cooling problems or fuel starvation. Have someone who really knows these cars go over your cooling system.

I can vouch that the 2.5's aren't that much slower than my 3.2 S (2002). Not only at the TOD but in addition NickCats and I spent quite a bit of time autocrossing and his last few events he was only 1.5-3 seconds behind me and I was on R compound tires versus his street tires (a lot of people say R compounds knock off 1-2 seconds from your time). Yes, I'm a bit quicker in terms of power but it isn't as dramatic as I thought it would be. IMHO the biggest difference in a "race" setting is the brakes. I'm going to get quite nervous when he buys race tread. ;)

It also helps that he's become one heck of a driver in a short period of time. :D

I Agree
 

I concur with the opinion of others here. On the street it could do with more power only for fun really as you can't use it seriously. I just took mine for a nice run and found some fantastic twisty roads, and I was unable to use all the power without the car getting aout of shape. So there is plenty there is you drive the car for the purpose it was originally intended.

Mine is my everyday drive car so it see's a lot of miles, but I still love getting in it even if it is just down the the shops to pick up some bread & milk.

My advice:

1. De -snorkle...if only for the sound, but I feels it adds a few horses.
2. Tyres. Well worth the expense for good ones.
3. Work on the handling although they feel more like a go cart than a car.
4. Forced induction
5. 3.4L swap.....from the new Boxy S or Caman would be great

Thanks, Sammy. What can I say, I had a great teacher ;)

Nick

I don't know why everyone always assumes that when you try to get more power out of the boxster that you're trying to go fast straight. I grew up a car guy and love to tune out and add performance parts whether it's suspension, brakes and engine. These things come from the factory de-tuned to try and work in all climates, elevations and available fuel quality. If you read my post I'm planning on updating the suspension and update the cooling system (oil included) and get as much as I can out of my car.

On another note, has anyone dropped their suspension 1.5-2" and added 19" rims? I haven't done the math to see if it'll work and would like to add the Brembo 6 piston calipers with 15" rotors while dropping the suspension and adding the 19's (19's are required for the large rotors).

^ I think everyone assumes you want more straight line speed in the Boxster when you mention HP upgrades. Because in the opinion of most people, the Boxster goes plenty fast for what the car is capable of, in turns.

Top 5 stright line speed HP increases

Trade in for a Hemi
Trade in for a Cobra
Trade in for a Vette
Trade in for a 911 TT
Trade in for a Mc Laren

I'm sure this list is debatable but I think you get the idea.

As said by my other well informed people here, the best way to make your car go faster is to get on a track and do some DE's and Auto Crosses with your local PCA. It really does make a big difference and you will really start to be amazed at how faster you are going after your 4th or 5th time out. The best thing about it though is that it is the one mod that you can take with you when you move on to your next car.

That's why you beef up the suspension and braking so you can go faster through corners and power out of them nicely.

Anybody heard of, or know of someone swapping the Porsche boxer engine for the Subaru boxer engine from the STI? One of the guys at my local Porsche dealership was telling me about it and how guys are doing it because the Subaru engine is easier and cheaper to tune out.

Yeah that is a perfect example of urban legend, Old wifes tale, and just Good o'l b.s. They say that because Subaru started coining the phrase "Boxer" engine (to ride Porsche's success) Their version is a 4 cylinder turbo. Porsche has been famous for their flat 6 which is basically a boxer style motor. This mean the pistons are in a flat configuration versus a V position or straight/inline style. For example BMW's are famous for their in line (all six cylinders are in a line and Chevy's are famous for their V8 four pistons on each side meeting in the middle hence V configuration etc. This rumor could have been further fueled by the article in Excellence Magazine a few months ago in which they did put in a Subaru motor in a early model 914. So yes, someone did do it. I'm sure that motor swap was more feasible due to the simple wiring in the earlier cars (in general) Keep in mind there has also been many engine transplant in 914's with Chevy implants etc. So in regards to a 986 with a Subaru swap, I really do not think so. It would be easier and probably cheaper the do a 3.4 (996) motor swap than a Subaru due to all the custom fabrication and wiring conversion. No bashing intended on the Subaru's...Yes, they are good cars and very fast.

Why would you do that?
 

Why on earth would anyone put a turbocharged 4 cylinder Japanese motor in a Porsche. Porsche are renowned for having some of the best engineering going around. Suburu are renowned for fast cars that last about as last about as long as a set of tyres (Ok I might be a little cruel)

If it's all about power why not whack a big block in there I'm sure you would get a few more horses.

Actually Subarus have a strong reputation for reliability and dependability, probably even stronger than Porsche's. The speed / performance tag Subaru is now wearing is fairly recent and limited to 1 car.

I have had Subaru's and the North American engines aren't suitable for high performance use, and they are in no way cheap to replace (JDM / European are a different block / bottom end of the engine). I had a bearing spin in my WRX (a very common problem problem with the N/A engines) and I could put a 3.6 in my boxster for the same money as fixing that engine!

Needless to say no more Subaru's for me.

Marc

yeah, too bad they turned it into a minivan.
i used to like the wrx and sti, now, well, looks like any other grocery getter with altezzas :rolleyes:

I owned a WRX which I had tuned to over 300 HP. Great car, but the AWD system is probably the biggest part of what makes it great - allowing throttle steering in turns and hard launches. The engineering of the engine though simply does not compare to Porsche's products. Porsches are designed to be sports cars. The WRX is not designed to be as highly tuned - the fact that you can tune them for more power just shows this. You can't get much more power out of the Porsche engines simply because they're already designed for great performance from the factory.

I would NEVER dream of dropping a WRX engine my Boxster. A 3.4 or 3.6 L sure, but a WRX engine would cost MORE and give you LESS.

My 2 cents
 

I have a 2000 S w/30K miles- I have the upsolute chip, FVD headers and short shift, Dansk 100 cell cats and muffler. I also added a cold air cone. HP increase? I don't really know, but I do know that these mods have not caused a single problem. Anyone concerned about these sorts of changes should take solace in the fact that I am thoroughly pleased with the changes. Great sound, wonderful performance, and zero problems! I say go for it!

I'm sorry guys, I have to laugh...the guy posted a total of 1 time back in late September, and probably won't return. It's almost like one of those types of post where a newbie just posts once to get the forum all stirred up, then posts links of this topic to the forum they regularly visit just so they can get some laughs.

I personally got a good laugh at how worked up some people got when I asked if anyone had heard of dropping a subaru motor in a boxster. Hilarious.

Thanks Good Forum
 

Cool share it is without doubt. I’ve been looking for this info.

why would one need to upgrade the brakes to anything more than a stock S brakes? those things are straight up amazing, throw some track pads on them and they are race ready!

1) AASCO Lightweight Flywheel
2) FVD Brombacher ECU Tune
3) IPD Intake Plenum/75mm 997 TB
4) KW Variant 3 Coilovers
5) Road Sport Supply (RSS) Underdrive Pulley Kit (UDP)

The above in no specific order.

I'm not an expert, but depending on what you are paying for your Boxster if you want more HP buy an S to start with. From my experience you can gain 45 to 50 output horse power at the wheels on a non S Boxster. It isnt hard but it is expensive, and you do not have to open up the engine. Ive done these
1. Exhaust modification 15 hp $2200
2. Desnorkle new air filter box 8-10 $350
3. IPD and 74MMT body 8-10 $980
4. ECU Flash 6-8 $998
5. Underdrive Pulley 6-8 $235
These were done to my 2003 tested with dyno scan software on quarter mile runs. based on actual acceleration weight of the car and time. Other factors were air temp, barimetric pressure, and humidity.
$4763 in parts I did all the mods

I know this is an old thread, but I think all the people saying the base model was "slow" were coming from vehicles that were much faster than the 2.5's ~6.5 0-60

Fastest car I owned before this was a Police Interceptor Caprice (purchased straight from IL State Police auction) with a V8 350 LT1 Corvette engine. 260hp (cast-iron block), 330 ft-lbs torque stock, and with custom CAI and headers 0-60 was 6.6, didn't test quarter but should have been high 14s because before headers with 7.2 0-60 it did a 15.1 quarter

2.5 Boxster feels much faster although they should be able the same, I think having a 5-speed manual makes all the difference.

So before anyone thinks they should keep saving for a 3.2/3.4 S here's my advice: don't, the 2.5 will be plenty fast and you'll save a significant amount of $$$ at the pump.

If your current car does 0-60 in less than 6 then get an S.

And I respectfully disagree.

S model 986s are not that much more these days, and they feel quite a bit faster behind the wheel.

I can't think of a single S boxster owner I've visited with that looks at the base model when driving by and says, "Gee, I wish I'd bought the one with a smaller motor."

However, many* of the guys who buy the base model will look over at the S in a parking lot or driving by and think, "I should have held out and found an S."

*"Many" does not mean every base boxster owner. But if you polled this forum asking non-S owners if they wish they had more HP and also wished they'd held out and found an S, you'd discover what I know oh so well—a sizable percentage would say their 2.5 box just doesn't have enough low end grunt for a car they plan to keep a long time.

I've owned a 2.5 200 hp Boxster for eight years now. I've spent wads of cash eeking out 20+ hp in an effort to get more power out of my motor and it's futile. Had I just waited a year and saved more for an S...