Tinker will happily sell you one. Infact he's even improved it since I bought it.

 

Anyone want to venture a guess as to what effective CR breaks factory rods?

 

42! No, hang on, that's the answer to the question of life the universe and everything.

 

Don't you worry, I've been in contact with Cody a lot lately

 

I'm running 19ish to 1 right now (only 20 miles so far ) and it hasn't killed my motor yet. When I was uning the ems, I hit over 14psi ( effective of over 21:1) and I didn't snap any rods. I really am starting to wonder how much boost the stock engine can take...and for how long of course. I think that once I get the funds together to rebuild the motor I will find out.

 

I would advise against it. You snap a rod (not that I've heard of this happening with our engine) and it usually exits via the block. Scrap the lot.

I've heard that our rods are pretty good. Someone mentioned the other day that they had aftermarkets and when they saw the stocks sent the aftermarkets back.

 

LOL awwww come on, I've always wanted to like James Bond and create an oil slick behind my car

 

[QUOTE=Scorpion,Nov 15 2005, 09:51 PM]I'm running 19ish to 1 right now (only 20 miles so far ) and it hasn't killed my motor yet.

 

First of all for an


I stay in the team with AusS2000 for the mean while (stock CR, fast spooling small-mid sized turbo and 8psi of boost). Lately it got colder in Dubai, the temps drop to 24-26C during nights ,car feels awesome and auto-x racing started again. I can not imagine having a laggy car for this type of racing. EVOs with HUGE boost are faster than me in a straight line, but in auto-x they just don't do well with a low CR high boost application. (hit the gas, order a pizza, boost kicks in and you already need to brake hard for the next corner)

I was planing to use the 2mm and drop it to 9:83 : 1, what would result in a effective CR of 16.51 with 10psi of boost and 17.18 on 11psi.
Sure the top end power would slightly improve due to the efficiency of the turbo in higher psi levels (correct me if I'm wrong but at 8psi a GT3071R is nowhere close to peak efficiency), but anything below 4000rpm would "suck" as per what Tinker (Cody) stated somewhere on this thread earlier.

Now my questions are:
1.) Can I run 8psi daily (well, "nightly", the car sees only 7500miles a year) and 10psi on "special" occasions (98OCTANE here, thats 93/94 in the states with a gallon of 110 in it) or is it just up to me to try and find out?
I know that some of us ran 9psi for a long period of time with no problems, but what about 10psi? That would result in a effective CR of 18.48 what is already 7.48points greater than stock.

2.) Does higher boost increases only the risk of detonation and can be "cured" with higher octane gas (if we still talk 10ps on 11:1CR not 30psi) or am I missing something else in the calculation?

I guess only time will tell.....

 

From what I can see, the 8psi applications are running just fine on a stock motor. Longevity is there as well. A supercharger kit at 8 psi, while not able to make the same sort of gains due to the inherrernt system losses, is still boosting 8 psi, and still has an ECR of around 17.0. The only difference is that it is experiencing the 17.0 ECR only for a very short amount of time compared to a good turbo setup at 8 psi.

You will probably be able to get away with an occasional (well tuned of course) 10 or even 12 psi setup on stock compression. Using higher octane fuel will most definitely help you avoid detonation and also yield more power. At the same time, the extra stresses in the engine are going to fatigue parts faster. Any FI application will fatique engine components faster. I am very interested to see what a safe limit is. By safe I mean, how much boost can the stock motor take on a day to day basis and hold up 100% of its integrity until the day I sell the car. (If that day ever comes.

These are the type of questions that don't get answered because there really is no answer. No one has the money to do a comprehensive test and blow through ten or twenty motors. We can only go by the experience of the pioneers. All of our turbo guys are doing their parts. Due to the relative reliability of the supercharger kits (they really are reliable when not tinkered with) I would venture a guess that 8 psi on stock compression with a good tune should last for a long, long time. Routine maintenence and all that jazz assumed. The fact that many SC guys have upped their boost with smaller pulleys on stock compression (tuning with the AEM EMS) also gives me hope for the turbo kits longevity.