Just Dyno'd my 98 2.5 986 with supercharger

[Aus986]

G'Day all,

I purchased a 2nd hand supercharger kit on this site just before christmas. It is finally installed and with a little help from microtech it made it to the dyno today.
Looking at 270rwhp running 7.5 lb boost. Working on the fact that is the only mechanical mod on the vehicle.
I was wondering if anyone could direct me to a good intake mod and a reasonable extractor and exhaust setup.
I will post some pics shortly gt2 bodykit 19' gembala wheels silver with black bonnet speedster humps so it looks the part.

Thanx

Aus986

Congrats! That's over 35% power gain. Impressive for a SC. You'll probably net another 7-10% on an exhaust mod since the already restrictive exhaust is more so with FI. I am guessing this is non intercooled.

Can you give us some driving impressions, like pulley whine, and power ramp up? What type of fuel management are you using? Any detonation?


Sorry I don't have any rec's for intake or exhaust. I'm shopping myself.

[Aus986]

the car seemed quick to start for some reason.
my business partner has a 996 911 carerra4 and 0-100kph we sat level (mind you his is auto)
I never dyno'd the car prior.
I haven't driven yet i just got the call from my partner with the 996 and he is not happy about the power gain (It doesn't matter to me how fast I go as loong as he is in my rear view mirror :P)
But the guys at porsche say without an exhaust it will bend rods .. I am not sure how true this is but I am also not willing to find out
There seem to be a few options for mandrel bent stainless exhausts on ebay US around $1100 US will get a full system I am thinking I will go that way

Aus986

[chgolatin2]

Hi, Evo intake should do the job well for an intake. Exhaust hmmmm thats a tough one, you can try Che's product or do some research on ebay but be careful with what you buy on ebay... a complete exhaust is going to cost some major $$$$ fabspeed etc.

Originally Posted by Aus986

G'Day all,

I purchased a 2nd hand supercharger kit on this site just before christmas. It is finally installed and with a little help from microtech it made it to the dyno today.
Looking at 270rwhp running 7.5 lb boost. Working on the fact that is the only mechanical mod on the vehicle.
I was wondering if anyone could direct me to a good intake mod and a reasonable extractor and exhaust setup.
I will post some pics shortly gt2 bodykit 19' gembala wheels silver with black bonnet speedster humps so it looks the part.

Thanx

Aus986

[Ray]

Any idea how your HP boost translates into 0-60 timing?

[blue2000s]

Originally Posted by boxsterz

Congrats! That's over 35% power gain. Impressive for a SC. .

If the dyno is right, that's more like a 65-70% power gain in RWHP.

[insite]

me thinks you are going to pop your motor. the TPC guys recommend removing any and all intake / exhaust mods prior to installing their kits. also, i seem to remember stock boost on a TPC setup being around 4.5psi. if you're running 7.5psi, you have a different pulley on your supercharger. be particularly careful running the car hard if it's cold. trent carter blew his supercharged 2.5 almost immediately after swapping the pulley to increase boost.

i'd talk with the manufacturer of the unit before you do anything at all.

[Gary in BR]

I agree...7.5 is ALOT....all of the kits sold here are in the 4-4.5 lbs range and the turbo isin the 6ish but it had an intercooler. I am of the opinion a 7.5 lbs will blow the engine.

My iA supercharger is running 4.5lbs.

But..hey run with 7.5 if it doesn't blow your in a year I may do up mine
Gary

[blinkwatt]

Originally Posted by Ray

Any idea how your HP boost translates into 0-60 timing?

"I have done the 2.5L SC (Supercharger) and it was fast. 0-60 in 4.95sec. The 3.4L maxed out gave me a 4.3sec 0-60 and will just roast the 19x10.5 rears. I would have kept the SC but I blew up my 2.5L, so I went to the 3.4L."

Straight from Trent.

Either choice will make your Boxster a monster.

[Gary in BR]

My 99 has the iA supercharger on it.

Here is a video of me doing a burnout and I have 19x10.5 or11's I forget. on the rear.

I know I hit the rev limiter a few times but burning out like this in a boxster is not something I am accustomed to.

I've done a few 0-60's in my car and I get the low 5's I think my best was a 5.1 or so.


http://www.youtube.com/watch?v=_dWS3Rwtc4c

[Aus986]

The motor is pretty have ing done only 70klms that's like 45k miles which i think gives it some chance of survival.

From what I am hearing the reason the motor would blow is only if you don't change the exhaust and inlet

???

confused

Aus986

[Topless]

The enemy is heat... and your right foot. Keep it off the rev lim. and enjoy the ride.

[insite]

Originally Posted by Topless

The enemy is heat... and your right foot. Keep it off the rev lim. and enjoy the ride.

in this case, the enemy is the cylinder pressure. the boxster already has a high compression ratio. add to that pressurized induction. now add to that a free exhaust and intake. now add to that an intercooler. all of this translates to way more air, which means way more fuel, which means way higher combustion pressures. you would essentially be burning over 50% more fuel per revolution than the motor was designed to handle. the motor internals are not sized to handle this.

if you replaced the pistons with a low compression variety, you'd probably be okay. with stock compression, you are going to blow a hole in a piston or snap a rod. it doesn't matter if your car has 45,000 miles, 145,000 miles, or zero miles. if it's overloaded, it's going to break. you absolutely are going to blow your motor.

what you need to do is ensure you have the stock intake, stock exhaust manifold, and stock supercharger pulley. contact the manufacturer of the supercharger system; they will verify this.

[Gary in BR]

I am by no means a mechanic but by just installing a supercharger and doing months of research I say 7.5lbs is more than any company is selling, I do know of a guy in Melbourne FL who uped his boost to these levels and he did blow his engine.

Did you get the chip reflashed? or add a extra fuel injector? I would track down the kit maker and contact them. If you post who made it I am sure someone here can point you in the right direction.

I really hope the best for you and I promise all of us want you to get the most power you can but with out blowing an engine.

Gary

[insite]

Originally Posted by Gary in BR

I do know of a guy in Melbourne FL who uped his boost to these levels and he did blow his engine.

that was trent

[Gary Gaukler]

I find it hard to believe that your car makes 270 hp at the wheels at 7.5psi. 7.5psi is a 51% increase in pressure over atmospheric; 270hp is approx. a 50% increase in rwhp (180 vs. 270). Hence either your supercharger is 100% efficient (which is impossible), or there are some huge gains in volumetric efficiency (which is unlikely). Maybe it's 270 at the flywheel? Even that would seem high...

Apart from this, I echo the comments made by others that unless internal changes have been made to the engine, it is likely to blow up soon at 7.5psi. Adding an exhaust or an intake is not really going to change that.

Best of luck (and I don't mean this in a facetious way)!

Gary

[Aus986]

yea
the kit runs an extra injector.

have pulled the boost to gimme around 240

apparently the suggestions are get it breathing and try to keep it at 240hp at the rears ans it swhould be fairly safe

Aus986

[Gary in BR]

That sounds tlike the TPC kit, they ran an extra injector.

My iA kit should be between 210 and 230 at the wheels so 240 will be safer than 270.

How did you change the boost?

Did you change the pully?


Gary

[Aus986]

not that mechanically minded.

I take it to my mechanic tell him it is running too much boost he returns it.
I am kinda figuring go down to 215 220hp now and with breathing aparatis it will hit a safe 240-250

you can feel the car struggling for Oxygen it is wierd

[MNBoxster]

Originally Posted by Aus986

not that mechanically minded.

I take it to my mechanic tell him it is running too much boost he returns it.
I am kinda figuring go down to 215 220hp now and with breathing aparatis it will hit a safe 240-250

you can feel the car struggling for Oxygen it is wierd

Hi,

It may not be struggling for O² at all, what you feel could be detonation...

Happy Motoring!... Jim'99