Super Dave

Why do I only see boost on the gage when the car is moving and under a load and not while sitting still and reving the motor up to the same RPMs?

theedge

You answered your own question, theres no load on the engine while its free revving.

testarossa_td

Interesting.....
You are still pushing exhaust (cylinders pulling a vacuum) which should spool up the turbo right???

As Tina Turner might say...what's load got to do with it

Jfrahm

If you really got the throttle blade all the way open it'd drop to zero vacuum, and eventually your turbo would make some boost. Without load there is no time for all this to happen before you hit the rev limiter. the turbo is spinning (as it always is when the motor is moving air) but not enough to create pressure.

You can try it, just put your foot flat on the floor and let it rev and bounce off the limiter. Maybe you'll get a little boost :-)

-Joel.

hosrom_951

Dave: if you are referring to the stock gauge, mine moves between the 0.4-1bar depending on how much "load" on idle. I can even get 1+bar on idle if i give it 70%+ throttle..........

Super Dave

Yes I have seen about 1 to 3 lbs of boost for just a second when flooring it at a sit still state.

No I stopped trusting that STUPID bar gage long time ago and bought a AutoMeter gage for under the radio. Since then my BAR gage has satrted to stick on various different readings of the gage. That gage is a joke. I plan on putting my Injector duty and Air/Fuel gage there in micro LEDs.

testarossa_td

Ahhhh Resistance is what we are talking about...aka LOAD.
With having to drive more weight the pressure has time to increase, where as if you have no load then it just flows on by and does not allow for pressure to build up.(comparing pressure at the same RPM-with and without load) Now that makes since....

So what is this Brake boosting I hear about???

Dash01

Brake boosting is when you are driving along, and to develope boost you load up the drivetrain. To load it up you stand on both the brakes and the gas. The engine is then fighting the brakes and working harder, creating boost. The car is still going the same speed, but is deveoping much more power. As soon as you let off the brakes the turbo is already spooled and everything is ready to rock and roll.

You can watch this in some of porshhhhh951's movies. I think thats his screenname here. He has raced some people and brakeboosts.

Atleast this is my understanding of it from what I have seen in the videos. I personally havn't tried it.

Eric

testarossa_td

I saw the Stang vids....Sounds like an unpleasant strain to the car.....

porshhhh951

unpleasant strain to the brakes. Never had one problem with the car.....modded it almost two years ago. 20psi daily...never had a hicup.

thanks for asking

Super Dave

John,
Can you post the list of go fast stuff you have done to your car? The list you run through in one of your daytime videos.
Thanks
SD

testarossa_td

What kind of brake pads are you using? I am guessing you use Super Blue in the lines....

Your tranny/rear end does not get strained by this??

porshhhh951

sure david. There's nothing really special about the car though...just the usual stuff you would find on a full bolt on 951.

Engine(rebuilt to OEM spec 33k ago)
Stage 1 lindsey head
Billet deverter valve
lindsey vac line kit
Lindsy 3inch exhaust system no cat 40series flowmaster muffler
Lindsey Dual Port wastegate(works wonders just as good as the tial INHO)
Lindsey Stage 2 Mass Air Flow system

Turbocharger stock 26/6(rebuilt 33k ago)


Monitoring and engine management
Power Perfect digital fuel controller
Pro-m maf burner
Koklen stage 2 chips with dave lindsey re-burn and tune
Autometer air/fuel gauge
Autometer boost gauge
Lindsey MBC

Suspension and chassis
Bilstein escorts
450lb spring front
400lb spring rear
poly bushings

Brakes
S4 calipers
pagid blacks
ATE super blue high temp fuild(SS lines are in the works as well)

Tranny and rear end(rebuilt 29k ago)
Quaffie LSD
Turbo S 1st and 2nd gear's
Steel syncro's
cup clutch
Kep PP(? questionable...dont know exact pp specs)
Oh and mobil 1 syn rear end gear oil(I like redline too)

On order corbeu seats/harnesses
possible lindsey cage
gutting most of the things I wont need and some things I might...haha I am just debating on weither or not to ditch the A/C or not.

Wideband in the future as well as a big turbo lindsey stage 2 intercooler with hard pipes. Oh and I wouldnt mind some vitesse chips....maybe to match their stage 3 turbo....eh who knows. Thats a way's off.

I am sure I am missing all kinds of little things but thats certainly all the stuff worth mentioning. Oh I also had a water injection system put on by a friend of mine who does them...usued that forawhile when I was boosting more than 20psi. I will be fitting a new system on the car in the future but, the turbo and other goodies need to go on first since he will need to know what we are working with.

porshhhh951

btw sorry I didnt think the list was that long but, it looks kind of long when you start listing it out.

Super Dave

Thats OK that is exactly what I wanted to see. I might even have more questions when I get a chance to stop and read it.