Twin Turbo 928 fixed and back out there terrorizing the streets!
#333
The first little sound bite, a co-worker took some spy footage:
http://picasaweb.google.com/lh/photo...eat=directlink
http://picasaweb.google.com/lh/photo...eat=directlink
#335
I will wrap it in something, ideally in a tube with a closed cell foam on the inside and mass loaded vinyl on the outside.
#336
The boost controller location
I did some repairs on the boost controller and figured out you might be interested in what we are using and where we mounted it.
This is the least offensive color scheme available among the generally ricer-Bling! boost controllers. It looks ok with the power off, but sure enough ricer-Bling! blue creeps out of it when the power is on, but as I said it's the least offensive of a really offensive lot.
I can see the display thru the steering wheel and I can easily change programs with my right hand, it's about as close as the ignition key and the shifter.
This is the least offensive color scheme available among the generally ricer-Bling! boost controllers. It looks ok with the power off, but sure enough ricer-Bling! blue creeps out of it when the power is on, but as I said it's the least offensive of a really offensive lot.
I can see the display thru the steering wheel and I can easily change programs with my right hand, it's about as close as the ignition key and the shifter.
#337
#338
Can't wait to hear some more of that sound before you do that ... nice
#340
http://picasaweb.google.com/lh/photo...eat=directlink
V-twin sound, in my opinion. It's not too bad, though, until one cracks open the throttle.
#341
What a beautiful sound .... so smooth. I've played that first one quite a few times .. that throttle crack is just awesome. I can only imagine what it sounds like if you really wring its neck.
#342
[QUOTE=ptuomov;7853954]A quick update:
Finally, here's the cover. Ignore my temporary spacers, they are not enough. The problem is that pump extends too far on the side. Any idea how to extend the bulge in the cover to about the red line area?QUOTE]
Hey Tuomo..
If you want to send me that cover I'll take care of it for you. Just mark it up to show how much clearance you need. I expect to be at the boston shark party and could bring it wth me.
Finally, here's the cover. Ignore my temporary spacers, they are not enough. The problem is that pump extends too far on the side. Any idea how to extend the bulge in the cover to about the red line area?QUOTE]
Hey Tuomo..
If you want to send me that cover I'll take care of it for you. Just mark it up to show how much clearance you need. I expect to be at the boston shark party and could bring it wth me.
#343
An update
Ok, so now I know how to silence a fuel pump. Products from Second Skin, prominently featured on:
I got Luxury Liner Pro from Second Skin, cut a piece from it. Then I used their high-temp spray adhesive and foil insulation tape to make a cylinder around the fuel pump from it. The closed cell foam goes on the inside and the mass loaded vinyl on the outside. The clamp tightens around the silencer cylinder. Now, the pump is completely isolated from the bracket and then the bracket is furthermore rubber isolated from the tank.
The lines from and to are reinforced rubber fuel lines. There's about a half an inch of just rubber hose between the fittings on the suction side so it can't and won't collapse. The rubber hose on the pressure side is run to the fenderwell inside a pipe insulation foam tube, which is held together by electircal shrink-wrap tube.
Under the trunk mat, there's a heavy MLV sheet glued to the thinner MLV & CCF composite. It gives marginal benefits with the fuel pump noise, but I left it in anyway because it's very effective in dampening the exhaust noise.
The pump noise is now acceptable even when run at the middle speed setting. By acceptable I mean one can't hear the fuel pump if the engine is running, even if the fan and A/C are off. This may be more of a statement about my exhaust mufflers than anything, though...
I dropped the cover at Dave's firm last night and he has very kindly agreed to modify the cover for me so that the cover doesn't touch any of the parts. He will also coat the part black. I will then coat the inside of the pump cover with Spectrum and bolt it on.
Can't wait to finish the fuel pump silencing project!
I have three hour tuning session scheduled for Friday night on a Dynopack dyno which can hold rpm constant. I've written a bit of Octave code for fuel and spark optimization based on the dyno data. I am going to give my *highly unproven* speed "secret" out below, just for ****s and giggles:
It'll be interesting to see if the engine survives the session and the car makes it to the 9/11 shark party.
I got Luxury Liner Pro from Second Skin, cut a piece from it. Then I used their high-temp spray adhesive and foil insulation tape to make a cylinder around the fuel pump from it. The closed cell foam goes on the inside and the mass loaded vinyl on the outside. The clamp tightens around the silencer cylinder. Now, the pump is completely isolated from the bracket and then the bracket is furthermore rubber isolated from the tank.
The lines from and to are reinforced rubber fuel lines. There's about a half an inch of just rubber hose between the fittings on the suction side so it can't and won't collapse. The rubber hose on the pressure side is run to the fenderwell inside a pipe insulation foam tube, which is held together by electircal shrink-wrap tube.
Under the trunk mat, there's a heavy MLV sheet glued to the thinner MLV & CCF composite. It gives marginal benefits with the fuel pump noise, but I left it in anyway because it's very effective in dampening the exhaust noise.
The pump noise is now acceptable even when run at the middle speed setting. By acceptable I mean one can't hear the fuel pump if the engine is running, even if the fan and A/C are off. This may be more of a statement about my exhaust mufflers than anything, though...
I dropped the cover at Dave's firm last night and he has very kindly agreed to modify the cover for me so that the cover doesn't touch any of the parts. He will also coat the part black. I will then coat the inside of the pump cover with Spectrum and bolt it on.
Can't wait to finish the fuel pump silencing project!
I have three hour tuning session scheduled for Friday night on a Dynopack dyno which can hold rpm constant. I've written a bit of Octave code for fuel and spark optimization based on the dyno data. I am going to give my *highly unproven* speed "secret" out below, just for ****s and giggles:
For each MAF signal and rpm:
x=[AFR, spark advance]
Torque = (1/2)*x'*A*x + x'c
Knock probability = e + b'*x <= d
If b'*(A^-1)*-c <= d, then xopt = (A^-1)*-c
Else xopt = (A^-1)*(b*((d-e+b'*(A^-1)*c)/(b'*(A^-1)*b)) - c)
x=[AFR, spark advance]
Torque = (1/2)*x'*A*x + x'c
Knock probability = e + b'*x <= d
If b'*(A^-1)*-c <= d, then xopt = (A^-1)*-c
Else xopt = (A^-1)*(b*((d-e+b'*(A^-1)*c)/(b'*(A^-1)*b)) - c)
Last edited by ptuomov; 09-09-2010 at 05:19 PM.
#344
Different ignition advances, boosts, and AFRs in the top end
Different ignition advances, boosts, and AFRs in the top end make a big difference. Here are six runs with different settings above 5000 rpm:
These are hp numbers from the rear axle, no correction for the driveline losses, standard correction factor, etc. The dyno is Dynapack load dyno, which is not generally a fairly tale generator like Dynojet.
Now, here's some data on the AFR and the like:
There's nothing to write home about in this, but just for the ****s and giggles there's the holy AFR in the internet-approved turbo range! ;-)
These are hp numbers from the rear axle, no correction for the driveline losses, standard correction factor, etc. The dyno is Dynapack load dyno, which is not generally a fairly tale generator like Dynojet.
Now, here's some data on the AFR and the like:
There's nothing to write home about in this, but just for the ****s and giggles there's the holy AFR in the internet-approved turbo range! ;-)
Last edited by ptuomov; 09-10-2010 at 11:53 PM.