HP, how much can a LIL 2.5L take? How do they Blow?

[efahl]

Originally Posted by pk2

250whp is certainly nothing to sneeze at, and that’s all stock? Tempting. I thought I’d seen “crank” numbers which didn’t seem terribly impressive.

I have forced induction. With a modest boost (a 10% pulley change) (and retuning) I figure I can hit or exceed 300 hp, (an arbitrary goal I set). I’d really like to do it though without blowing it up, to much fun to drive.

At 300hp would you still bother with new pistons? Would that be to lower the compression? Who sells pistons and other internals for these things?

Hi Peter,

My 3.4 has a dry cone filter in front of a bigger MAF body and custom plumbing to the throttle body, TTP headers and cats, and re-mapped ECU (the dyno numbers came from the mapping session).

I really don't know what's inside any Porsche motors, haven't torn one apart yet, so I don't have any reason to say the stock 2.5 pistons won't be good for 300 HP other than that they are pretty high compression for a boosted motor.

I would go to Wiseco, Arias or Ross for custom pistons. You can usually get them for about $100 each, at least that's the ballpark for Audi parts. Rods can be had from Pauter or Carillo for about the same, if the Porsche parts turn out to be weak (the 2.5 is the odd man out with 72 mm stroke, I'm guessing that all the 78 mm stroke motors - 2.7, 3.2 and 3.4 - share their bottom end components for stocking and manufacturing efficiency).

Eric

[efahl]

Ok, guys, time to start accumulating motor part info...

http://www.not2fast.com/porsche/engine_dimensions.shtml

Who has an engine taken apart, or has access to parts and can measure them? I'm very interested as to whether my speculation about the 78 mm stroke engines sharing crank and rods is correct.

Eric

[pk2]

Originally Posted by Gary in BR

IYour PS explanation is brilliant, makes everything nice and easy.


I think someone needs to try the nitrous... I would hate to be mid corner and the nitrous kicks in...


Speaking of Primer Grey Boxsters.....no I'm kidding...I... parts are 5 - 10 times more expensive and they are unable to pull the high horsepower numbers as easily.

Have a safe new years.

Gary,

Funny my little Postscript upstaged the preceding rambling paragraphs. As to nitrous, I’m personally more interested in power on demand as opposed to temporary power…seems like nitrous is really just good for a drag or 2.

True about mod prices for p=cars, thinking about volume+affordability of Boxsters might sometime justfy reasonably priced aftermarket stuff. But that never happen with my old 928…don’t know where they all went.

WI!

I stuck a toe in the WI waters today and it turned into a bit of a plunge. I bought a (standard issue) Sureflow 150/100 PSI meth/h20 pump on the cheap off ebay, great. So Then going back forth with the guy a bit, he winds up throwing in a bunch of bits and bobs that add up to about 85% of what I need for a complete a basic H2O/meth set up. (I’ve got another 50%, needed to make it work as good as any, (just need some brain power to make it work, a hack but one that’s been done)

So your turbo(s) is running 7 PSI with an intercooler. So if you can do that, I should to, with H20/meth cooling. That’s if I can “pulley” it up without over-revving the Super.

So, I’m committed. Round up a few more parts, pick a few more brains and I think I’m on my way to the Holy Grail, 280 +.

Regards PK

Ps, how did you extrapolate hp from your documented whp? Is there a rule off thumb for conversion? Yours is supposed to 290 hp @ 7 psi and mine is supposed to be 270-280 @ 4.5 psi. Must be a rule of thumb for that to; claims/actual=…)

[Gary in BR]

If I said I am running 7psi I made a mistake its only 6psi.
The last two days with the weather here so cold (its around 30!!) I have seen and felt 6.5psi. and 7 once or twice.


I think there is a rule of thumb for the whp to crank conversion. I think its 1.14 times the dyno number but I am not sure at all.

Here is how I did it:
Porsche claims 201 at the crank my base line dyno showed 164

164 times 1.22 is about 201.

226 times 1.22 is 275 crank.

I will assume right off the bat someone has a better way of finding these numbers but this is the "logical" way to me.

[pk2]

Originally Posted by Gary in BR

...its only 6psi.
The last two days with the weather here so cold (its around 30!!) I have seen and felt 6.5psi. and 7 once or twice..

-------------------------------------------------
That,s funny, I noticed a “cold effect” to, was out at night at maybe 45f a couple of times, engine temp half way up to 180. Rolled out of a parking lot in first and then just stomped on it, no clutching, straight line and i just “lit'm up” like I was on ice.
---------------------------------------------

Originally Posted by Gary in BR

...I think its 1.14 times the dyno number but I am not sure at all.

Here is how I did it:
Porsche claims 201 at the crank my base line dyno showed 164

164 times 1.22 is about 201.

226 times 1.22 is 275 crank.

I will assume right off the bat someone has a better way of finding these numbers but this is the "logical" way to me.

-----------------------------------------------------
Sounds like sound logic. Good enough for me. That’s about what I came up with using my own variables.

Heres How I did it. Using TPC’s claims of 70-80 hp and shaveing off the lowend by 15%...I get 60hp boost at 4.5 PSI.

60 (boosted hp)/4.5 PSI (boost) =13.3hp per 1 psi boost. So, 13.3 hp x 6psi=79.8 hp. So, about 280hp total

I’m probably dead wrong too.

Glad your at 6 PSI though. To get 7 PSI, my SC revs will probably be past recommended 14krpm's, and may be past the point of diminishing returns (more hp to spin it than it can put out).

Thanks PK

[pk2]

Originally Posted by efahl

Ok, guys, time to start accumulating motor part info...

http://www.not2fast.com/porsche/engine_dimensions.shtml

Who has an engine taken apart, or has access to parts and can measure them? I'm very interested as to whether my speculation about the 78 mm stroke engines sharing crank and rods is correct.

Eric

Pretty cool site Eric, I haven’t blown up this motor… yet, so I can't rip it apart & measure the stroke my self.

Be interesting to see if the 78's do share a crank and rods, would open the door to some interesting mods. I have "heard tell" though, that the Boxster's case is of a weaker design and maybe even metallurgically different.

I’m not quite psyched to rip my motor out and apart. I just picked up a real deal on an h20 Injection setup. From what I’ve read, they really do quite a job. So I don’t think I’m going to have a compelling (read necessary) reason to rip it apart to soon.

I’d really like to get a tired, cheap, 2,5…well forget that… 3.2-3.6 to pull apart and monkey around with it since there’s obviously a source for internals (like those you cited) make a swap when convenient. I wonder what practically & realistically can be done with them. (I’m really getting quite tired of “hp gain claim, game”)

Regards, Peter

[Gary in BR]

PK,

Good luck on the h2o instal.

Keep us informed on how the setup goes, how about pre and post dynos??

[pk2]

Originally Posted by Gary in BR

PK,

Good luck on the h2o instal.

Keep us informed on how the setup goes, how about pre and post dynos??

Sure will, for better or for worse.

Spent half the day trying to find the specs for the Boxster fuel injectors (cc/min.). Finally found it, need it for an equation to pick the right water nozzle/injector size.

3 different ways to run the injector, not yet sure what route I’m going to go.

Regards, PK


PK

[pinzgo]

Hi Guys, Just to make up to date on my project. I own a Boxster S 2000 with 32000 miles on it. Last year I added Supercharger, catback, headers, ecu reflash by IA, Bigger injectors, air intake, lowered suspension, Put aerokit and full carbon trunk lid after spoiler and brake light, hard top, porsche seats with carbon shell, Kinesis wheels, Short shifter, carbon console,
This winter I am addind intercooler in trunk with fan onto lid, nitro sprayed on intercooler and progressive water methanol injection just prior to trottle body to refresh engine some more to higher psi. So,With these upgrades I will put smaller pulley on supercharger to get almost 7 psi at trottle body.

I hope I will dyno it around 375 whp. I do street and quarter mile drag with it in a team with my sons. They have a S2000 and a STI. Huge feeling.
Add comments or recommendations please.

I would like to send you pictures, but I need somebody of you to tell me how to insert in posts. I am not a pro with computer use.

I appreciate you guys with all infos contained in forums
Jacques

[Gary in BR]

Jacques,

I am glad you finally made it here.

You and I spoke via email back in May of last year when you where installing your supercharger. Glad to hear that you got everything running.

You seem like you are coming at this project very aggressively and I commend you for it.

If you look back at some conversations we have had on this board, you will see some of us have addressed what you are about to do. We would love to hear the details of the fan on the intercooler and I for one would love to hear about the NOS on the intercooler.

You jumped into a conversation about mething an intake and it seems like you may already have it worked out. Please post what you have planned because it will help a few Boxster owners out.

Midway through this thread you will see a link to another forum where this conversation is taking place also. there is some good info on that thread also.

If you have pictures if the car send them to me and I will post them.

PM me and I will give you my email address for the pictures. I am out of town and only have my cell for the web so I can not check my PM until Monday. (I see I have 3 of them so if you are one of them I will get back to you on Monday).

One last note, you will get better answers and more help if you start a new thread and not cross post the same message 2 or 3 times.

Make it a great night, we all want to hear about this project.

[pk2]

Originally Posted by pinzgo

Hi Guys, Just to make up to date on my project. ...375 whp. I do street and quarter mile drag with it in a team with my sons. They have a S2000 and a STI. Huge feeling.
Add comments or recommendations please.

I would like to send you pictures, but I need somebody of you to tell me how to insert in posts. I am not a pro with computer use.

I appreciate you guys with all infos contained in forums
Jacques

Jacque,

You’ve done good with your post. Add am image by uploading it to a place like this: http://img87.imageshack.us it will give you a URL in a couple different formats. One will be for forums. Just copy and paste it under the text of your post and push “preview post”. It probably won’t work. So just try some others (URL formats) till it previews O.K. Press “submit reply”. Your done.

Sounds like quite ambitious with your “S”. I’m doing similar with my 2.5, boosting from 4.5 psi to 6 or so. I don’t think my little Eaton blower will do much more with out spinning itself silly and/or taking up more hp to run it than it puts out. Haven’t done the math yet.

I’m doing just h20/meth injection. As far as I can tell it alone should do the trick. I thought a lot about IC and the trunk seemed Ideal but I didn’t feel like cutting holes in my trunk so it could breath.

Have fun, keep us posted,

PK

[pinzgo]

Hi Gary and guys, I had to work on myself to go ahead with putting intercooler in trunk. I am just going to do it. First, I had to remove soft top to clear the space on top of engine cover. Pipe will join the one coming out from supercharger, pass thru the cover and carpet with an elbow that will run straight thru the wall (Yes, over the engine cover) get into intercooler and come back the same way to catch the trottle body.It is about 3 more feet of (insulated with fire resistant) pipe. Intercooler is a two parts one that I plug together. Pipe is all 2.5 inches diameter. With actual supercharger intake tubing, there is no way to pass under the cover. It also means that soft top will not fit any more. I will add hump when I will remove hard top. If it rains away from my hard top, we will bring shampoo and sure get anough water to take a shower. But running with hard top is another feeling I like better than lowered top. It is like running a torpedo. NOS will be sprayed outside intercooler only. The mechanic that has the right !!! to touch my car was member of ROLEX porsche racing team. He is my advisor. He recommends not to inject nitro into that type of highly engineered engine. Water methanol is more adequate to lower temperature, higher boost and save engine. That way, the trunk wall has a good access away from ECU and car tubing and wires. NOS and W/methanol will all be in trunk. Do not ask why I do so much on a boxster. I love the car, the shape, it's personnality and so on. It is my toy. Upgrading to 911 or so on does not tell me anything. If we look a boxster coming on the road, It looks like a smile !!!

Good night everybody, take care
Jacques

[pinzgo]

Just for a test. I followed instructions

[pk2]

Update: Pieces are starting to come together. Got new SMT6 AIC (anyone tuned one). Waiting on a water/meth. Tank. Got all the tuning gear, EGT, wide band with laptop interface and data logging etc. Found a deal I think on pulleys, think I’m going to up 2 more psi or 30-35hp.

Not sure how I’m going to handle tunning while juggling timing, w/i injection & and a/f at once.

Regards, PK

[Gary in BR]

I assumed you had been busy with the car, we haven't heard anything in a few days.

I uploaded a picture of my temporary gauge cluster the other day on out intercooler thread. http://986forum.com/forums/showthread.php?t=14282&page=3&pp=20

My next phase...
Cat delete!!
I am deleteing my only pair of cats and install a set of electronic cutouts for the exhaust. I will be able to run almost complete straight pipes or quiet it down for long trips or that cell phone rings.

The only question I still have is weather or not I will run the cutouts via boost or a switch.

With this mod Turbowerx feels I will getter faster spool and possibly a little more boost.
The exhaust mods may be 45 - 60 days away it all depends on my mechanics schedule.

[pk2]

Originally Posted by Gary in BR

I assumed you had been busy with the car, we haven't heard anything in a few days.

I uploaded a picture of my temporary gauge cluster the other day on out intercooler thread. http://986forum.com/forums/showthread.php?t=14282&page=3&pp=20

My next phase...
Cat delete!!
I am deleteing my only pair of cats and install a set of electronic cutouts for the exhaust. I will be able to run almost complete straight pipes or quiet it down for long trips or that cell phone rings.

The only question I still have is weather or not I will run the cutouts via boost or a switch.

With this mod Turbowerx feels I will getter faster spool and possibly a little more boost.
The exhaust mods may be 45 - 60 days away it all depends on my mechanics schedule.

Hey Gary,

Cats eh? Is that a significant bottle neck in the system? It seems like there isn’t much in the exhaust system to change that buys you much except peace of sound. I’ve been looking for electric bypasses for quite awhile myself. I was only going to do it for sound (ala Pedro sport exhaust) if it was cheap and easy. It’s easy but not terribly cheap.

Have to be really careful out here screwing with emissions, every 2 years It’s a real nail biter. When my time comes up again I’ll be posting looking for clueless smog stations in So. Cal.

Right now I’m trying to sort out this AIC. Nice. versatile piece of work, but for the versatility you’ve got figure what you have. I.E. theirs 8 different ways a car can send an rpm signal x dozens of variations on each of those. Then comes the tunning…

Regards, Peter

[efahl]

Originally Posted by pk2

When my time comes up again I’ll be posting looking for clueless smog stations in So. Cal.

Hey, new neighbor, I'll let you know what I find out... I just moved to San Clemente last week (from southeast Michigan), so I need to get my car smogged and tagged. I've got a good connection, I'll let you know how it works out.

Eric

[pk2]

Originally Posted by efahl

Hey, new neighbor, I'll let you know what I find out... I just moved to San Clemente last week (from southeast Michigan), so I need to get my car smogged and tagged. I've got a good connection, I'll let you know how it works out.

Eric

-----------------------------------------
Great,

San Clemente eh, used to surf just south of there at trestles and San Anofre (sic) (AKA Sano/oldmans) all the time. I’m up here in Tustin.

There was a source posted on PPBB a while back about a place in Laguna Hills. Had Porches, Ferraris, etc lined up around the block to get smogged. Gotta figure yhoough, someone going to catch on (or has).

Out here you’ve got pass the sniff test and the like plus a visual.
Please do let me know what you come up with.

Regards, Peter

[Gary in BR]

I am glad its you trying to figure out the WI. It sounds like you are going to get great gains from the research I have read.

Is there so much work involved with the tuning because no one has added WI to a Boxster before?

As far as the cats go, the research I have done shows that turboed cars get some boost and power increases because the turbos can spool faster. In the 996tt there is a power gain by removing the cats. In a few weeks we will know if a 986tt has the same effect.

If I dont get and power gains and just get some sound back, the turbos have muffled my sound a little. I will be happy with just the sound. I need my car to be a little louder to live up to the sinaster license plate.

[Topless]

PK,
Richard brought his 914 to the PCA breakfast today for show and tell. Air cooled 3.1L 6cyl, turbo with intercooler, 500rwhp, 1600 lbs soaking wet. Whew! That thing will easily outrun a Viper in a straight line and corner like a Cup Car.