what would i need to do in order to run 18 psi, but being able to turn the boost down for when i dont want it that high? i was thinking some sort of manual controller in the glove box or something..... what mods would i need? (im stock right now)

 

I have a **** next to my steering wheel. Pretty damn tempting isn't it? I will ask the previous owner what he did to have it set up that way and get back to you, unless someone else knows off hand then feel free to step in.

 

Turbo or TurboS?

At a minimum, you'll need chips to meter fuel appropriately to match your increased flow-rate and to remove the overboost-protection. On a Turbo, 18psi would be about 240rwhp. Not much more than 15psi because the K26/6 isn't too efficient at the higher boost levels (it heats up the air too much).

On a TurboS, you may need injectors. And 18psi would be good for 290-295rwhp... maybe???

 

240 is that stock? or with the guru set, test pipe, adj fpr, k&n filter?

 

Typically around 220-230rwhp @ 15psi for the GURU Chip Upgrade with a K26/6. Cranking it up beyond that gets minimal gains. Test pipe is worth 5-15hp max depending upon condition of catalytic; primarily helps with high-end boost. Notice that Euro-951 w/o catalyst is rated 220bhp vs. US-spec 217bhp.

Adj. FPR isn't helpful with chip-upgrades, but can be with a programmable system. K&N in stock airbox is iffy at best. Some sample dyno-charts of chip-upgrades here: <a href="http://forums.gururacing.net" target="_blank">GURU Forums:</a> <a href="http://forums.gururacing.net/viewtopic.php?t=30" target="_blank">Dyno Charts - Stock turbos + chips</a>

How's your chip-upgrade performing?

 

I'm very confused?!?!?! Doesn't a STOCK 951 put out 217hp and a S puts 247 down to the pavement? Or are these to the flywheel? I hear people doing mods to thier 951 S and getting 250hp. Isn't that what you started with?????

 

All factory HP/TQ numbers are at the flywheel.

 

Velvet,
The factory figures are to the flywheel. So, 240 hp to the pavement reflects a pretty significant gain.

As a side note, I don't know of any manufacturer that reports hp figures at the wheels. The flywheel hp makes them look better. ;-)
-Jon

D'Oh! I'm too slow

 

I still don't get why these people who give numbers at the flywheel think that they look good. What you put to the ground is what counts. These cars with over 300 or even 400 horsepower are putting 15-20% less to the ground.

 

because FW HP is ALWAYS then same and you know exactly how much HP your engine has. This is not the case with the US dynos where every dyno shows a different HP number for the same car with the same engine.
In Germany all 951 show about 220 HP on the dyno (stock)
What it this on a RWHP dyno? I saw numbers from from 170 to 210 for the same car. the problem is bigger with Tuned cars.
So either use an engine dyno or buy a GOOD dyno like MAHA etc. They are accurate within 2-3 HP on a 390 HP GT3cup car and this for over 50 cars now even on different days different temps etc.
This is what Porsche, Audi, VW and BMW or other good Tuners use and the HP and torque curve is exactly the same as the one you see on the factory sale brosure. You can't be more accurate.

check the last dyno at Deman Motorpsort on the 944 web forum and you will see the problems with these kind of dynos. different HP for the 951, total off (too low) for the 968 etc. and this is the case with all dynos I saw till now. A good dyno can show you EXACTLY how many HP you have on the engine AND on the R ear wheels. so no need for guessing!! 12% 16% 20% lost or what?
I usually use 16% for a dynojet and I hope it is somehow accurate. Since all US tuners use this older dyno technology you have no other choice but to use a factor for the HP loss. Except Miledge and Protomotive I do not know of other tuners that have an engine dyno.
anyone has a good roller dyno that calculate wheels AND engine HP at the same time?

Konstantin