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

[pk2]

Originally Posted by blkboxster

i think the motor can handle that amount of power, Garry seems like hes doing fine.

Ya, he seems to be defying conventional wisdom. Wonder how many others are out there.

PK

[Topless]

PK,

As far as instrumentation goes you may want to add a GPS logger or G-timer to get some real world acceleration curves coming out of turns and down the straights. They can match up to the other telemetry data from the car. You may want to talk to Richard at Clewett Engineering in LA. He specializes in engine mgmt. systems for Porsche racing teams. He has more experience with tuning FI Porsche motors than anyone I know. He is far more comfortable at the ragged edge of performance and reliability than I am.

Gary's car is posting some good numbers. 11k miles with a 270hp+/- turbo may be a new record for a 2.5 motor. It's an accomplishment to be proud of. Still a long long way to go to see 200hp/liter though. Now that would really defy conventional wisdom. One step at a time.

[efahl]

Originally Posted by pk2

And if I wasn’t already where I’m at I’d consider a 3.2, 3.4 or 3.6. I am surprised though at the relatively modest power gain with such significant displacement increases (and hassle), not much bang for the buck.

PK,

It's not so much that the peak HP, but the fat torque curve that the 3.4 gets you. Any gear, any time, just mash the pedal and it goes. Stomp it in first and the traction control kicks in (if the pavement is wet, same thing in second, no clutching needed, just floor it). Just for comparison, my engine is putting down 259 rwhp on the dyno, about 9 more than the motor produced in the C2 from which it was pulled (headers, exhaust, intake, tuning et cetera).

I'm running a stock G86/00 (code CWA) five speed transmission on my car, with a light flywheel and sport clutch, and it hasn't broken yet, even with a fair amount of abuse.

Regarding your original question, I have yet to see a German motor that could not take at least 75 HP per cylinder; older iron-block Audis are good for about 100 per hole with stock internals. I would expect the stock bottom end in a 2.5 to be good for 400-450 HP without problems (going forced induction would prompt me to put in different pistons though, I'd lower the static CR and increase the height of the top ring land).

Eric

[JAAY]

Hey, Sorry to get into this one so late. I did have gary's supercharger, I was going to put a 7lb pulley on it. If you do the water injection on it there will be no issues with heat at all. It is very reliable and safe to run more boost. As a matter of fact the damn thing runs too rich anyway. They detuned the crap out of it to make it more reliable. I have since sold the charger and am now doing the 3.4 swap. As far as I can see it is going to cost me just around 8k to do it.

[Gary in BR]

Jaay,

Glad to see you in this one.
I thought the map was too rich myself. I have a dyno that at the end of the pull the car kicked out a little black smoke.
http://www.youtube.com/watch?v=5X5IUNKJMgQ

PK,
You asked if I am running an AIC....I must be on my backup brain today becasue I dont know what AIC stands for.

Dont worry you guys will be kept up to date on the mods.

[JAAY]

Yea, when I talked to the guys over at turbowerx they even said that too. Well I am in the market still for a 3.4 if anyone knows of one. That project has been put on hold though for a few months. I warped the heads on my saab so that is getting a new motor in the next couple of weeks. When it rains it pours.

[pk2]

Originally Posted by Topless

PK,

... You may want to talk to Richard at Clewett Engineering in LA. He specializes in engine mgmt. systems for Porsche racing teams....
Gary's car is posting some good numbers. 11k miles with a 270hp+/- turbo may be a new record for a 2.5 motor. It's an accomplishment to be proud of. Still a long long way to go to see 200hp/liter though. Now that would really defy conventional wisdom. One step at a time.

I’ll try to get a hold to Richard, see how talkative he is. ? Engine management is something I get in principle and a bit in practice but I’d like to know a lot more to give this little motor a fighting chance. I don’t suppose he haunts any of these forums?

Gary’s #’s are indeed enviable, especially in the light of the total mileage on the car. Shame nobody’s ponyed up with some aftermarket internals to accommodate the stuff we’re hanging of the outside. I’d like to hit a 150/liter mark and on paper it’s no big feat. But weather the motor can hold itself together long enough to become boring is another story. Wish I knew more about the pratfalls

One step at a time, true. I really need to get what have buttoned down and baselined before I mess with take another step.

Regards, PK

[pk2]

Originally Posted by Gary in BR

Jaay,

PK,
You asked if I am running an AIC....I must be on my backup brain today becasue I dont know what AIC stands for.

Dont worry you guys will be kept up to date on the mods.

AIC is a crappy acronym, in that means a hundred different things. In this context it’s “Auxiliary Injector Controller”. It Times and squirts an extra injector, and usually tweaks the timing to. Saves messing with the ECU for Fuel and timing tweaks. So if you have a seventh injector you probably have one of these things…an AIC.

Regards, PK

(PS I “hunted” JAAY down last night in order to invite/drag him into the fold…)

[pk2]

Originally Posted by efahl

PK,

It's not so much that the peak HP, but the fat torque curve that the 3.4 gets you. ... I would expect the stock bottom end in a 2.5 to be good for 400-450 HP without problems (going forced induction would prompt me to put in different pistons though, I'd lower the static CR and increase the height of the top ring land).

Eric

Eric,

Thanks for your input.

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?

Thanks, PK

[pk2]

Originally Posted by JAAY

...If you do the water injection on it there will be no issues with heat at all. It is very reliable and safe to run more boost. As a matter of fact the damn thing runs too rich anyway. ....

----------------------------------------------------------------------------------
JAAY,

Glad I found you & Have fun with the 3.4. Hate to pester you, but you’re the first person I’ve heard of that has messed with this sort thing in the same way I’ve been planning to.

I’d come to the conclusion on my own that H20/methanol would do the trick nicely and then some, but I’d not heard of anyone doing it. Only lot’s of horror stories of catastrophic blow-ups, (likely due to detonation).

I was planning to “pulley” just up to 6 PSI, a little nervous though with all the urban lore. Thus this thread. Did you have it on good advice that a 7lb boost wouldn’t hurt you with the h2o/meth injection (or was it an educated/extrapolated conclusion)? What sort of WI system did you opt for; a simple progressive stage 2 type? or a Stage 2 with MAF input (or similar feedback)?

And finally, were you concerned at all with stress on any of the internals? I know it will have a wear out faster, but as long as it doesn’t go boom I’m alright with it.

Thanx a ton, PK

BTW, Are you doing anything to your 3.4 or are you leaving it more or less stock.

[JAAY]

I never did the kit on the boxster. On my eclipse I have a boost activated kit on it with a 50/50 mix of water and alcohol. The 3.4is only getting headers and exhaust of what I already have and a sport clutch. I am hoping to get a motor in January. I may put a 6 speed in it too

[David N.]

BTW guys, Willow is nice but remember, yer driving a BOXSTER! Leave the fast track for the rocket cars and try out Buttonwillow for some real corner-country

-David

[Gary in BR]

I am only running 6 injectors.

With the supercharger and the turbo the ecu was reprogrammed. GIAC did the sc program and Turbowerx writes his own programs. So to answer the question I am not running an AIC.

From my memory FVD was selling different cams for the 2.5 I do not know if they are still available.

I am sure as the priced of 2.5 Boxsters drop the tuner market will get more involved, by this I look at history. I have had my car almost 7 years and when I first got going desnorking and a cold air intake was it, then the exhaust systems came on the market. Now look at muffler and headers, how many combinations are there??

The 1st generation of superchagers and turbos where very expensive and an engine swap was 20-30k. Now it seems you can have your choice for around 10k.

I will imagine the few of us on this board working on more power for our cars are not the only ones doing this. Within a few years there will be more mods for our cars and more power.

I for one would love to see more power out of my 2.5 so I will continue working toward that goal.

PK,
I believe the IA supercharger runs 4.5 psi and I know I am running 6psi with the turbo. If you pulley up to 6 with the sc I would look into doing an intercooler of some sorts. I am basing this on the IA not having an intercooler and they stopped at 4.5 the turbo is running 6 and is cooled.

I know you did some intercooler research, what have you decided to do? I assume the water/meth injection??

At one time you where wanting me to measure my intercooler, do you still need those numbers??

[JAAY]

Lets just fix the power issue with a 125shot of nitrouse and pray everytime you squeeze. Cost would be under five hundred and fast install with real results

[pk2]

Originally Posted by Gary in BR

I am only running 6 injectors.

With the supercharger and the turbo the ecu was reprogrammed. GIAC did the sc program and Turbowerx writes his own programs. So to answer the question I am not running an AIC....I am sure as the priced of 2.5 Boxsters drop the tuner market will get more involved, ... Within a few years there will be more mods for our cars and more power.

I for one would love to see more power out of my 2.5 so I will continue working toward that goal.

PK,
I believe the IA supercharger runs 4.5 psi and I know I am running 6psi with the turbo. If you pulley up to 6 with the sc I would look into doing an intercooler ...
I know you did some intercooler research, what have you decided to do? I assume the water/meth injection??

At one time you where wanting me to measure my intercooler, do you still need those numbers??

Gary,

Funny I had the same thoughts regarding ageing Boxster prices and the availability of aftermarket parts. It’ll be a blessing and a curse. First time I see a primer grey Boxster, I’ll hang mine up.

I kinda figured your setup was a holistic approach. A reprogrammed ECU, fine tuned with all pertinent components in place is pretty ideal. But, to your question about remapping the ECU, if the mods you make are significant, without having the ECU remapped with your mods in place, you might not be getting all you can.

As to the intercooler, if your rolling around down there, I’d be curios about its size and that of the inlets, I haven’t ruled it out completely. WI (water/alcohol injection) just seems to be better suited for my setup. (That’s the short answer).


The long: The problem is the length/volume of air between the blower and the cylinders. To plumb an IC (intercooler) in on my setup would mean a lot more plumbing plus the intercooler volume = a lot more volume of air/fuel to compress, this takes time… read lag. Since my torque is quite low-end (opposite that of a single turbo), and this where the lag would be most pronounced, it could be pretty screwy with an IC, compressed torue curve.

With WI, I don’t increase the volume of air/fuel to compress at all. It also doesn’t matter where I put the hardware; just need a hole into engine compartment for a water line and a couple of wires. As best I can tell, it every bit as effective as an IC, maybe even better.

The trade off is that mine would be an active system needing to be fed, nurtured and maintained and yours is completely passive. The extra plumbing/volume in you IC system is probably negated because your turbo’s might well be a “2 Stage” deal; one works the low-end & when it fizzles, the other kicks in and works the top end (total speculation on my part, but I know they do it)

I’m with you, I’d like to tap all the “squirt” out of this “little 2.5” I can. My sc is supposed to be at maxed out 4.5.psi to. I think that must be the cut off before detonation sets in and when you need to start some IC or the like.

Anyway, that was breathy..

Regards, PK

P.S. If that’s all confusing (and it probably is), think of it this way, what would it take you to blow a little beer bottle up to 2 psi, not much. Now blow a 5 gallon jug up to 2 psi…. lungs = blower, bottles =air fuel volume, (tubes, IC, etc.)

[pk2]

Originally Posted by JAAY

Lets just fix the power issue with a 125shot of nitrouse and pray everytime you squeeze. Cost would be under five hundred and fast install with real results

Honest,

I like the Idea of a seamless power on demand. Living in a mass sprawling metropolis, you got get your jollies when & where you find them. A surprise lack freeway traffic, an empty sweeper of an off ramp, forgotten old side streets. or some semi protected hilly twistys.

It would seem a tank of gas will use about a gallon of H2O/meth. Funny thing, and give me your opinion: I’ve “heard tell” of people happily using windshield washer fluid for there WI. I presume it’s because it’s a nice blend of alcohol and H2O. I haven’t looked into how clean the water is or its percentage in the mix and what else might be in there.

Regards, Peter

[pk2]

Originally Posted by JAAY

I never did the kit on the boxster. On my eclipse I have a boost activated kit on it with a 50/50 mix of water and alcohol. The 3.4is only getting headers and exhaust of what I already have and a sport clutch. I am hoping to get a motor in January. I may put a 6 speed in it too

Hey Jaay

From what someone posted here, the 3.4 has plenty of kick. But why not a 3.6?

I have a contact somewhere who rebuilds 6 speed that are mate-able to a 2.5 if your interested, it sounded like they could one fit to anything you want.

Regards, Peter

[Gary in BR]

Originally Posted by pk2

As to the intercooler, if your rolling around down there, I’d be curios about its size and that of the inlets, I haven’t ruled it out completely. WI (water/alcohol injection) just seems to be better suited for my setup. (That’s the short answer).



P.S. If that’s all confusing (and it probably is), think of it this way, what would it take you to blow a little beer bottle up to 2 psi, not much. Now blow a 5 gallon jug up to 2 psi…. lungs = blower, bottles =air fuel volume, (tubes, IC, etc.)

I will be under there in the next few days. Measuring for my bottom brace.

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


I think someone needs to try the nitrous Jaay brought into this conversation. Now that would be an interesting combo. I would hate to be mid corner and the nitrous kicks in...


Speaking of Primer Grey Boxsters.....no I'm kidding...I hang out with a few Honda Acura tuning guys and most of them would not want to mod a Boxster because all of the parts are 5 - 10 times more expensive and they are unable to pull the high horsepower numbers as easily.

Have a safe new years.

[JAAY]

just got home from work. Happy new year. 6speeds, I would love more info on whoever you know that has them. As for the 3.6 I do belief that there is a lot involved with that swap and lot more cash also. I nkow we are all made of money and bought boxster because the gt2 is just a girls car or a cgt is just too slow LOL. Just joking, price is a factor to me. Time for bed the lady is calling, happy day 1 of 2008

[Gary in BR]

PK,


Read this thread, there is a link to a guy who did meth/water on his Porsche.

Post what ever info you find.

http://www.6speedonline.com/forums/showthread.php?t=112475