Check my posts on this subject. It took a lot of work, $ and good thinking to finally get this car to do the things I want but I am there now and will eventially go to about 600+ RWHP. I have the Whipple from SoK but needed extensive modifications to make the thing reliable and make big power. For street I run 94 octane and 10-11 lbs boost with a BIG intercooler and 8:1 JE pistons. Extensive mods to the engine were needed to even get here. I will put a bigger sc in soon and that will require a G50 trans swap and race gas to run 16+ psi. Also I strongly suggest the motec system for control this is what I was told is best and will put it in soon. Unfortunately, all this plus the other mods to the car cost big $$$ that I would never recoup if I sold it. This is always the case as can be seen by Juan Ruiz selling his car for 65K which I bet is a lot less than what went into the car and his is a turbo which is easier to build. Right now I have to replace the centerforce clutch because on the first pass at a dragstrip I tore the disc to shreds and ripped material from the pressure plate and flywheel. I am now going to use a SPEC clutch at the Stage 5 level. I hope it can be driven on the street even though it is not street friendly. Oh well, good luck to all of you.

Best regards,
Gerryhttp://forums.pelicanparts.com/uploa...1132363824.jpg http://forums.pelicanparts.com/uploa...1132363920.jpg

What will lowering the compression do to the power of the car? I am way new to turbo and supercharging so bare with me. I understand higher compression engines are not good to do forced induction so lowering piston compression is needed. Sounds like people end up lowering the compression and adding more boost to get the power?

Though it does sound like a contradiction to add boost and to lower the compression, but it doesn't get you back to where you originally started. Even at 8 to 1 compression with 7 PSI of boost, you are at almost 12 to 1 compression. Lowering the compression will increase the reliability of the engine without sacrificing much power when the boost isn't on.

Too much heat in the wrong place at the wrong time will cause problems, such as detonation. Compression causes heat so thats why God invented intercoolers , race gas and electronic engine management systems etc. which allow us to make big power from small engines. Do the research , get a plan and alot $$$ before going down this road as itis a very slippery and steep slope. HP is addictive and Porsche HP costs big $$$. Good luck.

Best regards,

Who has best prices on JE 8:1 pistons? Buy used, or only new for pistons????

Group buy anyone?

Gerry,

Nice car and congrats for going against the current and making it work. I'm going off maninstream and trying TT's. I will most likely need to add a tail to my project. May we see more of your car with lid closed from rear angles? I only have Carrera flares on mine and wanted to see the (3.8 ?) wing on yours. Thanks

Absolutely, here are a couple. When I get the car back I will take some dedicated rear end shots for you. Also, good luck with the TT. My next upgrade may be a twin supercharger but I am having trouble finding data on one that was built.

Regards,http://forums.pelicanparts.com/uploa...1133377133.jpg http://forums.pelicanparts.com/uploa...1133377154.jpg

Ok so ive got my car torn down and one of the pistons is fried. other ones look to have cracked rings but not as bad. Ill post a pic of the glory! :-)

I have a guy Dick Elvrude who supposidly know his ****. He says i need turbo pisons 7.5:1 with turbo cylinders since they are forged? Is the 911 turbo version called a 930?

I found out that the funny gauge in my car were from a company called J&S out of California whos literature says its sytem will detard knock individually per cylinder on the fly, via microprocessor. Hmm dont know if it was working at all after the dammage i saw on the pistons

ill keep you guys posted. and get that picture up.
*edit* added picture
http://www.thenwhomebuyer.com/websit...033_176517.JPG
Similar sized Chunk tanken out of the cylinder wall. Other cylinders were ok.
tauran

Ivallt,

First, I respectfully disagree that you NEED to go as low as 7.5:1. But this partially depends on the type of fuel and timing control system you use.

Second, an aftermarket knock sensor is only as good as the person who tuned it. This is beyond the actual ability that it may or may not have. A 911 is inherently noisy. A solid lifter engine is loud. Some knock sensors are less than acurate by design. How does it effect the engines managment system? Does it compensate the fuel or timing? How much timing were you running static and at full advance? Were you running vacuum or mechanical only advance or was it actually computer controlled.

Sure, I will agree with forged pistons. They are more consistent in molecular structure. Therefore they are not only stronger, but have less chance of hot or thin spots. Strong detonation will still destroy a forged piston, though. A good forged piston with no detonation can withstand moderate pressure without breaking.

Watch detonation. Watch EGT. Watch AFR. Buy some gauges.

Dick does know his stuff, he is very well respected. However, I don't know how many Supercharged motors he has built....

Cheers

Well good to hear someone knows his name.. I was wondering the same about if he had much experience with supercharged engines. He does know alot about engines and Porsche 911 ones as far as i can tell, plus he sounds like he is very trustworthy. I cant say the same about some others. I think the engine will be excellent when back together, i just want to protect it with some intellegence, IE properly tuned chip, and a good working knock detard device or wideband sensors.

Recommendations?

Lukesportsman,
Dick is doing a good job hooking me up with a good price on something that should be dependable(turbo, Mahle pistons). He thought JE pistons wouldnt be NEEDED for the $. I think 8:1 would have been fine as well if available.

Here is what i know is installed
http://www.jandssafeguard.com/safeguard.html
http://www.jandssafeguard.com/Universal/

I belive i read that it changes the timing either on all cylinders at once, or if chosen, separatly per cylinder.

There is ALOT i have to learn abou this car and what its at. I need to get someone who can read the chip settings.

Like I said earlier, Dick has a great reputation. You probably will not find anyone with something bad to say about him. You could also check with Steve Weiner about his thoughts, he is a great guy and local to you. He also knows Dick very well. I have done a lot of business with Steve and he has always treated me and my customers very well.

Cheers

Some other pics.http://forums.pelicanparts.com/uploa...1133420846.jpg http://forums.pelicanparts.com/uploa...1133420863.jpg http://forums.pelicanparts.com/uploa...1133420882.jpg

911VELOCITY,

What headers do you have? Did you keep the heat?

Kevin

I am using a set of Jet Hot coated racing headers, no heat ($500 + coating) but I don't have the name handy at the moment (get it later at home). It is time now to switch back to the SSI system for the winter which gives me heat. This is the only solution I have been able to come up with at this time but I hope I can fabricate some sort of flexable aluminum insulated piping that can be routed around and attached to the racing headers that could provide enough heat when hooked up to the cars heater blower system to get through the winter. I lose some HP going to the SSIs vs the racing headers but I don't want to freeze and drive the car.

Best regards,

What is the diameter of the racing headers VS. SSI? Is that why you loose HP?

Kevin

Yes, that is why. The SSIs primaries are 1 5/8 I believe and the headers are bigger, I think 1 3/4. For up to 300 HP I believe the SSIs are great as they provide good flow and velocity for both torque and high end HP but I have considerably more power and feel a significant difference at WOT. My experience with SSIs is excellent and I don't think there is a better product (with heat) for these applications and that includes many of the big name/ big buck companies which make absourd claims and when installed actually decrease the power. Not dogma, JMHO.

Best regards,

Gerry,

Have you looked into Protomotive's (sp) solution to heat? They run a ducting system off of the engine oil cooler since their headers don't have heat also. Just a thought.....

http://forums.pelicanparts.com/uploa...1133471040.jpg

Does anyone know if that actually makes any heat?

Cheers

No, I haven't seen that. I will call them and see what's up. I hope it works but I must admit it doesn't look like it could heat an ant here in NJ when it gets below 0. As catca says "does anybody know if this makes any heat??" Anyway, thanks for the info every little bit helps.

Best regards,