refresh951

Getting ready to go to "11"

fwb42

Shawn, Any chance that you'll be coming to the 944 Fest in Ohio this June. I'm sure many of us would love to see your car.

blown 944

Nice to hear that Shawn. I'll be doing the same very soon!!

refresh951

Well, got shut down at the dyno tonight. I always start with a 15 psi shakedown to check everything and AFR was a bit high. Added some fuel and made another 15 psi run and AFR got a bit worse. This was very strange since yesterday everything was perfect on my test runs.

Got home tonight and pulled the tank filter because I had an issue a couple weeks ago with E85 contamination. The filter was in bad shape (see below). Almost like a sealant coated the filter as it was almost water tight (see video). Guess I am going to have to flush tank this time and change the fuel filter again.

After washing the filter with a small brush and hot soap and water it flows like it does not even exist, I pour water in and cannot get it to hold anything.

eman930

Wow that sucks... Hope it's not the gas tank breaking down from the e85... Hope it's not in those new injectors

URG8RB8

Well that does suck Shawn. This is an alternative station or the same one that sold you bad fuel the first time? I have not had a chance to pull mine and look at it getting ready for my trip to the Final Four this weekend. When I get back I am definitely going to look. Although my car is running very good right now after that additive. So I think I am clean. Looking last night at my FP thread for that link Bas sent to me (which I could not find) I saw a picture of my strainer and it looked brand new. This sat with E-85 in the tank for nearly 18 months. I added some Stabil for E-85 before I left for Thailand though. When I got back I topped off the tank and ran it. Replacing the strainer was after all of that. I just filled up tonight and checked the hose at the pump and mine has a big in line filter on the hose. It even has a cert sticker on it and it was replaced last October. It did not say when the next one was due though.

refresh951

Thanks! It does suck! Then I remember that this is what I do for fun. Had to remind myself tonight to enjoy the journey

New station but I got 10 gallons in clean cans. I did not flush the tank last time but I drained it and changed the fuel filter. Tomorrow I will flush the tank. Tonight I found out about another station a lot of guys have been using with good success. I will go fill up at this location tomorrow and add the additive. Hopefully that will take care of this.

Pauerman

Wow that is great troubleshooting on your part Shawn!

I am amazed at how much of a restriction you were seeing with the screen. Do you think your pump has been compromised as a result of the restricted flow?

refresh951

Tonight was indeed frustrating but after looking at tonight's 15 psi shakedown dyno I know I am making progress. Below is one of my early dyno pulls with this motor at about 15 psi and a run from tonight. A lot of the difference is the new intake.

Paulyy

Here you are

Because i wanted to see too!

Crazy Eddie

Bummer but great move on testing, before going for the," Full Glory Run !! "
Eric was all excited today, telling me ... "Just 3 hrs to Shawn's run "
I was waiting on the edge of my seat .... waiting for the big crazy numbers
Hi Five on the find though.
Mine had sludge on the filter, when I pulled it ( after 6-7 yrs of sitting there and never was change ) Your looks like sand ???
Best regards
Ed

V2Rocket

thats a great power gain, but there's a huge torque tradeoff..looks like 30-40ftlbs through a big range.

still...beast

refresh951

Well, kind of. With a large turbo car I think the thinking can be changed a bit but I have not been able to get the numbers yet.

We generally compare motors/setups based on manifold boost pressure but with a very short runner intake I am not sure this is really fair. The stock long runner intake provides quite a bit of dynamic charging in the mid range. It really is amazing what the stock intake does for a K26/6 car or an NA. The intake effectively provides 2-4 psi of boost across the mid-range. This dynamic charging is essentially supercharging the cylinder greatly increasing VE. So when the stock motor is running 12 psi of manifold pressure the cylinder is seeing something like 14-16 psi! When a short runner intake is running 15 psi of manifold pressure the cylinder is seeing 15 psi (if the runner is short enough to push resonance above the max rpm).

The downside to the stock intake is that it really kills the top end. When Porsche designed the intake I think it was a "no brainer". With a long runner intake, they could dramatically improve VE across a large part of the powerband in the range the average user utilized essentially for free. But when you have a large turbo setup that operates frequently at high rpm, the stock intake becomes a bit of a liability. The long runner air column becomes sluggish at high rpm limiting VE.

With a large turbo one can use a short runner intake and increase manifold boost pressure to compensate for a great deal of the mid range loss of dynamic charging and the top end will perform much better. With a short runner intake the pressure the cylinder sees is essentially the intake manifold pressure because of the absence of dynamic charging. With this approach one can use higher manifold boost pressure than one might normally deem as "safe" because it is really cylinder filling that counts. Peak cylinder filling occurs at peak torque and this is the torque that generally poses the most risk to the motor.

I am planning to demonstrate that with a large turbo 3L+ motor, one can use a short runner intake to better shape the torque curve and make a lot more top end power without much loss in the mid range. This will be done by increasing boost pressure by 2-4 psi (so with this approach you will compare LRI@15 psi to SRI@18 psi manifold boost pressure) I will match cylinder filling by using MAF logs. The turbo will produce more heat but one can run more pressure than we are normally use to without posing more risk from a tuning standpoint. Many have run short runner intakes. The Supra guys have been doing this for quite some time. Not for everyone and there are trade-offs but for some large turbo/high rpm motors I think it makes sense. So yes, kind of.

333pg333

When you look at the tq at 4k it's still over 350ft/lbs which is plenty. If you're shifting hard through the gears you won't drop beneath that anyway. The improvements in the top end are a winner. Not that you can really compare exactly dyno's done months apart. But good signs I reckon!

V2Rocket

I wonder how much more power there is to be had, seeing as its not dropping yet at the end of the run...

Shawn, maybe time to play with retarded cam timing? You've still got tractor-torque where you need it.