Bang for Buck Mod
 

There are several companies that can tune your Boxster for $$. Good for 15-25 Hp. I like to tinker a bit, have 02 S model and ready to dabble. What is the one reasonable mod for several hundred dollars? So far upping to 74 mm TB with 987 Ypipe comes to mind. Tuning is more closer to 1K. Your thoughts.

Try a secondary cat delete. Top Speed offers them for $200 and should be good for 4 to 6 hp. It should still pass CA smog as it will not throw a code as long as they don't do a visual which most don't on these cars.

Other good option is a underdrive pulley. Also about $200 and is worth about 5 hp.

Anything else get real expensive relative to the results.

I used to live in Pasadena for 35 years.

Good luck.

The best bang for the buck is an underdrive pulley. Count on 5-7 ponies for about $200. Cat delete pipes can also net you 5 or so hp for $200.
ECU tunes are really expen$ive, and may net you 15 or 20 hp if lucky.
Spend the other $700 or so fixing the other rear fog light... :D

I second the under pulley mod. Desnorkle is a good free mod. It may not give you any HP but it sounds nice.

Wont give you any horsepower but I purchased a Short shifter from a forum member (http://986forum.com/forums/diy-project-guides/54726-ball-bearing-short-shifter.html) bought a new shift knob and replacement boot all for around $225 and I absolutely love the difference. I think the aforementioned underdrive pulley and Top Speed delete pipes are probably better if your looking for performance gain but the shifter does increase the fun factor.

Aftermarket headers made my 2.5 about 18 HP stronger with before/after dyno pulls. They're not expensive.

However, I'd have to agree with others here that the underpulley really gave me a kick in the pants when I downshift that nothing else has provided.

Fred's projectors will take 15 years off for about $375. Also adds a minimum of 30hp. ;)

http://i875.photobucket.com/albums/a...E7CA67C230.jpg

987 air box with K&N air filter, 996 76mm TB and 997 Distribution T. I know this mod gave my 3.2L a 20 HP bump. This engine loves more air. Doing the mods yourself should be around $250 max. This makes a $200 Under Drive Pulley 5 HP look silly.

EDIT: Maybe $300 for the air intake upgrade. I forgot to add in some extra pieces you'll need and the silicone couplers.

Next on my list is headers, secondary cat delete pipes and Borla muffler.

Kram - have you detailed this mod on the forum anywhere? IE, picts, part numbers, install process, etc? Would love to see this - very interested in this mod myself...

It's a nice Mod but you almost need the engine out to pull it off. I've seen some other cut off the outlet pipe and remount the original MAF in my opinion this defeats the purpose.

http://i1199.photobucket.com/albums/...psc9cn3nau.jpg

http://i1199.photobucket.com/albums/...psqxlrmp4f.jpg

http://i1199.photobucket.com/albums/...pstf1cgjiq.jpg

http://i1199.photobucket.com/albums/...psu4patl4g.jpg

Bang for Buck mod
 

Kram, I would be interested too, what is the toughest part of this conversion? Did you need to pull the engine? This sounds better than the IPD conversion. 20 or so more ponies at a fraction of what they want sounds like a no brainer. I am new to the Porsche scene but do turn a wrench. I love these cars!
By the way, is this a pure safe swap without the need of a tune after? Thanks,

These are the threads I got my info from. You don't need the motor out to do it. I can give you the part numbers, I'll need to look them up.

http://986forum.com/forums/performance-technical-chat/32074-987-v-986-air-box.html

http://986forum.com/forums/general-discussions/31693-maf-throttle-body-diameter.html

Mine.

http://i59.tinypic.com/11ka8ph.jpg
http://i59.tinypic.com/2moqzxl.jpg
http://i60.tinypic.com/s2z720.jpg

I second Kram here, finished my TB/plenum swap couple weeks ago. The 2.7 gets places on the freeway now, very happy.

I will add that secondary cat deletes and exhaust (I did Beluga Racing - <$300 for the backbox, but still blows fiberglass), will give you a response/hp boost, and AWESOME sound. And that sound is awesome all the time. My brother used to DD this car completely stock, and when he drove it after the exhaust he felt it was just what it needed. Still quiet cruising, no need to yell on the freeway even with the top down.

90038502504 - HEXAGON-HEAD SCREW 6 - ES#1377250 Need 4 of these

N01152427 - WASHER - ES#1882232 Need 4 of these

http://www.ecstuning.com/ES1511639/ Need 2 of these

99711031900 - Throttle Body Gasket - ES#1498080 Need 1 of these

99711041603 - DISTRIBUTOR TUBE - ES#1498085 Need 1 of these

This silicone hose to connect your TB to your intake pipe.

Racing Silicone Hose Elbow Coupler Pipe 3 15" to 3 15" 90 Degree ID 80 mm Black | eBay

This silicone hose to connect your your MAF housing to the intake pipe

Black 3" 3 0" 45 Degree Elbow Silicone Hose Coupler 76mm Intercooler Pipe Turbo | eBay

You will need 2 of these to clamp the silicone hose to the TB and to your intake pipe.

1pc 3" 76mm Turbo Silicone Hose T Bolt Clamp 83mm 91mm 301 Stainless Steel | eBay

Get these to mount inside your intake pipe that goes to your TB, only 2 will fit in there, but the set comes with 4. Adds strength to it as it's flimsy.

One Set of 4 Hub Centric Rings Size 71 5mm to 75mm | eBay

You can probably reuse your plenum gaskets, but I went ahead and bought 3. I could have reused mine.

Porsche Boxster s Intake Manifold Gasket Manifold to Head Set of 3 Genuine | eBay

Search eBay for a used 987 air box. I got mine for $75 shipped on a Best Offer.

Search eBay for a used 996 TB. I got mine for $100 shipped on a Best Offer.

Search eBay for a K&N air filter, if you want to use one.

You have to reuse your MAF housing off your 986 air box or the ECU can not read the air volume correctly.

I wanted to be able to clip a 987 MAF house back onto the 987 air box so I could get more air into the motor, but that requires a tune, so I molded the 986 MAF house inside the 987 MAF housing. When I get the headers, cat delete pipes and Borla muffler, I'll get another 987 MAF house and have a tune done on the car, so all I have to do is unclip the 986 MAF house and clip in the 987 MAF house and get a bigger intake pipe.

http://i59.tinypic.com/2moqzxl.jpg

You will want to get a plastic iron for this. Hope you have a Harbor Freight around as I broke 2 of them and just took them back and exchanged for new ones.

80 Watt Iron Plastic Welding Kit

You will also use this to cover the hole in the 987 air box. Cut out a piece of the metal screen that's included with the iron kit, melt it into your 987 air box hole, then use the plastic strips in the kit to seal the metal screen. I also wrapped the end of the intake pipe that goes to the MAF housing with the metal screen to give it more strength, melted it into the pipe, then melted the plastic strips around the metal screen.

Or get one off eBay, but be very gentle with it.

80 Watt Iron Plastic Welding Kit Bumper Repair Jaguar Mercedes Fiat BMW Ford | eBay

You will need to fill in the gap around the 986 MAF house to the 987 MAF housing. Use this as it melts when it gets hot from the plastic iron. You don't fill it up completely, just enough to seal it.

Permatex/Tube flowable silicone windshield and glass sealer 81730-1 at AutoZone.com

Get these to make it easy on yourself filling in the gap.

http://www.amazon.com/gp/product/B007Y8230G/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

You will also want to glue the bottom of the 986 MAF house to the 987 MAF housing. This keeps it in place while doing your work.

http://www.amazon.com/gp/product/B000LGT0GI/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

I also used the Honeycomb air straightener so the MAF sensor could get a more accurate air volume reading. You will need remove the 987 MAF house screen and cut out the 987 plastic to install this. You will also need to trim a bit of plastic away from the inside of the 986 MAF house to get the Honeycomb air straightener to fit inside it.

http://i60.tinypic.com/s2z720.jpg
http://i57.tinypic.com/1jn51v.jpg

Honeycomb for MAF You'll want the 75mm size

Use the clamps you took off your old Distribution T to clamp the Maf housing to the intake pipe silicone house.

This is a time consuming job, but the end result is well worth it, when you mash the throttle the car goes like stink and the intake roars.

One more thing. If you do it the way I did mine, follow Brad's advice in this post or you will not be able to mount the 987 air box with all the screw hole mounting points.

http://986forum.com/forums/282373-post122.html

The hole I have circled in red will be the screw hole you can not use unless you give the air box some extra room. Take one of the blue grommets and roll pin off your old 986 box, put it in that hole then get a screw bolt that is long enough to reach the screw hole treads in the chassis and tighten it down.

http://i62.tinypic.com/2n685so.jpg

Bang for Buck mod
 

Kram, Thanks for sharing. You are quite the resourceful Genius! I am definitely pursuing this route above any other mod. Is there a procedure for resetting the TB or just relearns from first startup? What a great write up / details. I'm sure there are many aboard that appreciate what you and some others have contributed to this subject. What a car huh?

You will want to have your battery unplugged while doing this mod. After you're done turn the ignition key to on and let it set for about 15 seconds, then turn it off, pull the key out, put it back in, turn the ignition key to on wait for another 15 seconds and start her up. The ECU will be set to the TB and start tuning for the increased air flow.

So you took the end out of the 90mm MAF, jerry rigged it in the 75mm original MAF, which you then reused. The air box is mounted without all the grommets and screw, and the tubing although larger than stock is still reduce throughout. Why did you bother?

You could have got the same air flow improvement out of the original air box by de-snorkeling, replacing the original inlet tube with a 3" smooth pipe with no chambers, and a high flow air filter.

The improvement for this mod come from using the 90mm MAF and 3-1/2" air inlet tube.

http://i1199.photobucket.com/albums/...pstf1cgjiq.jpg

The metal above the MAF inlet joint need dented up about 1/2" (Brad Roberts told Kram this needed to be done in his previous posts about this mod) All the screws and grommets can then be mounted along with the 987 MAF. 1, 3.5" coupling sleeve from eBay. 1, 3.5" to 3.25" 90 degree elbow from eBay, 1, 8" x 3.5" aluminum air tub from eBay use about 4", 4, 85mm - 100mm clamps I use 4 stock 987 intake clamps. No glue no epoxy no rigged connector. The tune from a 2004 986-550 Spyder

What isn't mentioned is the cross flow tube need removed, TB needs removed, plenum needs removed, the drive side intake need removed, fuel rail needs disconnected, wire harness needs unclipped from plugs injectors and sensor on the driver side and pulled back. Driver side air grill and the snorkel need removed. before you can remove or install the old air box and the 987 air box. To improve access to the lower part taking off the driver side rear wheel and wheel inter liner help along with the driver side header pipes.

Or remove or drop the engine 2-3".

the tune from a 2004 spyder will only work on a 2002- car (7.8 dme). I was able to get the airbox in without denting anything (you do have to modify the airbox by removing the muffler, and getting it in is a bear but very possible with engine in place).

from what i recall the 987 MAF housing ID is 83mm not 90mm (vs the 986 76mm) but yes, reusing the oem maf housing does keep one restriction in the system but is necessary unless you retune your car - oem tunes can be used (5 mins with your indy and a pst2/piwis):

2002- use the spyder tune
-2000 use a 2000, 2001 996 C2 3.4L e-gas tune (the 1999 was cable throttle)
5.2 dme cars? dunno. cable throttle cars? dunno.

while keeping the restriction in the system isn't the perfect solution, you still see benefits as can be attested to by most who have done the work. compared side by side, there is no argument that the 987 airbox can move more air than the 986. the other thing to realise is that this is a change to the overall principle of operation of the intake - from a reducing diameter system designed to accelerate the air into the cylinders and facilitate induction at low rpms, to an unrestricted system designed to move a lot of air at higher rpms - in this context reusing the oem maf housing is not that bad a compromise, although I could understand in jsceash's situation the 3.6 might suffer more from the restriction than a 2.7/3.2 car.

Holy Cow, KRAM! Thanks for sharing, this is an amazing write up! Now I just have to get up the nerve to try!!

"jerry rigged"? I'll have you know that's the most professional looking 987 air box to stock 986 MAF I've ever seen. Why did I bother? 20 HP gain for not much money is why.

This is "jerry rigged".

http://i149.photobucket.com/albums/s...S/IMG_0802.jpg
http://i149.photobucket.com/albums/s...S/IMG_0803.jpg
http://i149.photobucket.com/albums/s...S/IMG_0807.jpg

Are you just a complainer? Did you not read my post as to why I did it this way? I also gave the links on how the installs are done and then posted the parts needed.

Your in a dream world if you think a 986 air box with a high flow filter is going to match the air flow the 987 air box will deliver, even with using the stock 986 MAF housing. My car is so much faster after this intake upgrade I have to get new brakes as I'm hitting the corners at such a higher rate of speed, the stock brakes are not cutting it, even with the "restrictions" and no tune needed.

Question asked, Best Bang for Buck Mod. So do you want to spend $200 on a UPD for 5 hp gain or spend $300 and get 20 HP? The car roars at WOT with the snorkel on, runs better through the hole RPM range. This is a Mod you will feel, UPD, not so much.

You're welcome. This is a time consuming Mod. The hardest part I found was getting the last bolt out of the intake plenum. I took the Plenum completely out of the way, makes installing the 987 air box easy. I didn't have a hard time at all putting the 987 air box in place. Second hardest thing, making sure you cut the silicone hose to the proper length. Tip on cutting the silicone hose itself, take one of the clamps and tighten it down on the hose were you want to cut it, then just use a box knife cutting right at the clamp, makes a nice straight cut.

No I don't live in a dream world. If you have some documented data on your HP gain post it so we can see.

Here is what I've done in five years of tracking a my car starting with the original 2.7 motor. I can say for some time I've run almost every configuration of air intake on track and have hours of data recording to back them up.

In the 2.7 with an smooth 3-1/4" inlet pipe upgrade plenum and 74mm throttle body stock MAF stock air box desnorkled. My recorded improvement is 19-20 HP

The next year I ran a Agency power box with a cone filter a SLIGHT improvement.

The next year I had the 987 box stock MAF. The rest was the same as above. I had "NO" improvement in HP or Torque. But I wasted an entire weekend getting it installed IHAVE NO PROBLEM SAYING IT WAS JERRY RIGGED. I could only get 2 bolts in it was cockeyed high in the front low in the back and towards the motor in the rear.

Using your prices the straight pipe throttle body and plenum would have been $170 without 4-6hours removing the intake injectors and all the other crap.

This is a fact I can say the 987 air box never was installed right until I removed the 2.7 motor to install the 3.2/3.6 conversion. It's flush to the cover now the flange had vibrated against the top spot Brad had previously mentioned and made a flat spot that was nearly through. It was bad enough I bought another one.

This may be the case on your setup with a 2.7L engine. I've read the stock ECU tune can only compensate up to a 20% increase in air flow. I've also read that the ECU can not correctly read the air volume when using the 987 MAF house without a tune. Sounds like when you put the 987 air box with the 987 MAF house you exceeded the 20% air flow, which would yield the car running lean and with the 987 MAF house a tune was needed. I'm surprised your HP numbers didn't go down.

It's also a known fact that Porsche put the smaller air box on the 986 to keep it's performance down. They cut the nuts off the 986 with that air box.

You do make a good point, in the fact you can get a 20 HP gain with just upgrading the intake from the stock 986 air box.

$170 to get 20 HP increase, hands down the best bang mod for the money. Really makes the UPD for $200 and 5 HP gain look even more silly.

I've always estimated I got a 20 HP increase, but always felt is was more. My brother who has taken many rides and driven my Boxster before the intake and air box upgrade. I took him for a ride after the upgrade and also let him drive it. I then told him about the header, cat delete pipe, Borla muffler, 987 MAF house and larger intake pipping with a tune plans. His exact words were. "Your car is too fast right now, you don't need to do those upgrades". He is 6'-3" at 260lbs, even with the extra weight of him in the car, his impression was the car is too fast already.

For those in the know then, should I look for certain year 987 intake 997 distribution T, and 996 TB? Same for every year? I'd like to start gathering all parts. Thanks.

987 air box are all the same. When looking for the 996 Throttle Body, make sure it came off a 996 model number 99660511501, some people will list them for a 996 and they came off a Boxster. The 997 Distribution T make sure you get one that looks like the one I linked to, the turbo models are different. You probably can't beat that price.

You could also look for a 997 TB model number 99760511501.

Anyone see gains on a 2.5, or is the stock air box 'right sized' for the smaller motor?

Pedro offers a kit.

TechnoPower Kit

You can have this guy bore your TB and do your own thing for the rest of the air intake system.

http://www.maxbore.com/pictures.html

Bang for buck mod
 

Kram, Did you end up shaving off the top of the 997 -T for clearance? I recall you expressing earlier in another thread of a thick ridge hitting starter.

I have not yet. I plan on doing it though. It's not a huge issue and depending on the car's transmission will depend if the starter get's in the way. The trans on the left is a 6 speed and the Tiptronic trans has the starter in the same higher location, so it get's in the way.

http://i60.tinypic.com/vdjz2s.jpg

Just talked with the man at Softronic. He said using the larger 987 MAF Housing will yield no gain with the 996 TB, is could also hurt the cars performance even with a tune. He also said do not go to a larger TB, like a 82mm TB on a stock 3.2L engine (no internal engine changes). It will actually hurt the cars low end performance. The 996 TB he says is what to go with and stick to the 986 MAF housing.

So all I have to do now is get my exhaust upgrades done, forget the larger 987 MAF housing. I will be getting a tune from Softronic as I want every bit of HP I can get out of this engine.

Bang for buck mod
 

Thanks, Thats nice to know we are utilizing the best combo of parts to up our ponies. And I hope you don't mind one more question. Just for clarity, for our 987 intake the only needed part is the unit and flat snorkel? I was concerned about the small rubber elbow for Maf to air but I don't need either.correct? Thanks,

umm ... so what was porsche thinking when they put it on the 550 and added 8 hp? the 550 is basically your engine with the 987 airbox / maf housing and a factory tune.

no gain? not likely. most likely no gain for softronic. you've been upsold. instead of 1/2 hour at your indy getting the spyder tune pushed onto your car, now you're out $800 to ... softronic.

The 996 TB can only move so much air, the 82mm MAF house would do zero good. I told the man I was more then willing to buy the MAF housing and the Maf sensor the 550 Special Edition came out with. He told me it would be a waste of my money, we got into discussing the air velocity and everything, it was quite a long talk. I was really surprised he took that much time with me. The 550 Special Edition only has 6 HP over the standard 2003-2004 Boxster S not 8 HP and that's at WOT. What was Porsche thinking? Save money and make the HP look as good as possible, while the around town drivability is probably not as good as a standard Boxster S. Come on TRK use your head about it.

I called two indy shops and neither could push a 550 Special Edition into my car as they do not have the tune. I asked how much they would charge to push the tune if I got it, $800 to push a tune. At least with Softronic you get the Durametric cable which will work on your car with Durametric software.

Yes, you could just get the 987 air box with the snorkel. Cut your 986 MAF housing off the 986 air box and plumb it to the 987 air box. I think you would still want to get the 75mm Honeycomb air straighter and mount it into the 986 MAF housing. You will have to shave a bit of plastic off the inside of the 986 MAF house to get it to fit (I used a dremel to do that) ,that also holds it in place so it doesn't get sucked into your your intake.

i don't think anyone ever recommended using a gt3 tb on a 3.2.

wiki lists the 2003/04 as 258 and the 550 as 266 - that's 8 hp increase.

as i've stated previously (in this thread, for example) the role of the intake mod is to go from a reducing diameter intake designed to accelerate the air and benefit low rpm power (your "around town drivebility") to an intake that works better at high rpm because it flows more air by reducing the amount of restriction (accelerating air takes work). so, either have an oem reducing diameter intake (did you notice that the oem air pipe on your car is a smaller diameter at the tb than at the maf housing? that the tb is 2.7" ID and the maf housing is 3" ID? - that's reducing diameter - as the air gets drawn in it has to either compress or accelerate as the amount of space available decreases - this accelerating air rushes into the cylinder and increases power. works good when the engine needs help breathing, but just gets in the way when the egnine is trying to breath hard) or mod your intake to move as much air as possible. putting on a big tb, big plenum, and big airbox, then leaving a restrictive pipe in the middle, does neither - it slows the air down instead of accelerating it, and it serves as a restriction to airflow. if you already have the big tb, big plenum and big airbox, then you are already expeneincing any loss of low rpm power you are going to experience - not much, is it? changing that one pipe sitting by your airbox is not going to reduce the amount of hp your car makes.

it took me 5 minutes with a pirate porsche pst2 to do my row flash. it is not an $800 job. the mechanics you checked with probably don't have the tool and are quoting you softronic, giac, pedro, or one of the others.

I suggest getting your 550 Special Edition HP numbers straight from the horse's mouth. It's only 6 HP more at 264 HP.

Special Edition Boxster® S Celebrates 50 Years of the 550 Spyder

"For added performance, the new Boxster S edition is equipped with the most powerful engine ever offered in the Boxster model line. Rated at 264 horsepower (SAE)"

Yes I am looking to increase the size of the piping between the MAF housing and TB. Was looking on eBay earlier today looking for some 74mm I/D pipping. Right now with the stock piping the car has no normal driving issues and when you drop the throttle, she goes like stink. I don't know how the larger piping is going to effect the car's drivability, but once I get it done, I'll share the information.

Bottom line is, the 987 MAF housing is a zero gain using the 996 TB. If a person wanted to use the 987 MAF housing, he would want to use the 82mm TB, but you would need valve work done to the heads. The stock motor just can not take in the extra air without internal engine mods. 996 TB with the 986 MAF house is largest you would want to go on a stock 3.2L, your power band is perfect with that setup, no normal driving issues and will suck all the air she can at WOT.

Got the larger pipe ordered, but it's coming out of China and had to order a fitting for the Tiptronic venturi tube from China too, then will have to have the fitting welded onto the pipe. So it will be a bit before I have any feedback on that.

Kram, Need another clarification, on the Honeycomb 75mm for Maf they come in different ratios for cells. Remember which one? Seems default on website is 4:1 ratio. Gathered most parts and getting jazzed!

The real problem isn't the 987 MAF or the 996, 76mm throttle body. It the stock 996 Plenum. There is a lot of engineering data some in this post.
http://986forum.com/forums/general-discussions/31693-maf-throttle-body-diameter-10.html
That discuss the problem, which is the Plenum design that create a massive turbulent blockage.
Then a spin off where a members was designing a retro plenum, very similar to IPD's design. I don't know where this led after the thread died.
http://986forum.com/forums/diy-project-guides/55966-intake-plenum-911-throttle-body-4.html

The IPD does make this transition but the price is somewhat objectionable to some members.

Pipe
 

KRAM36 where did you order the larger pipe from and what size was it?
I to am wondering if the larger diameter exhaust pipe will give me a pick up in HP
and still provide enough back pressure. My CAT by pass is 40mm.