GIAC Stage 4 Race program
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[QUOTE]Originally posted by Neil
What's the difference in turbo life expectancy between those run at 1.0 or 1.1, and those run at 1.2?
Originally posted by Dock (Atlanta)
I sustain 1.2 bar with my GIAC Stage 2... [/QUOTE
Sustained 1.2 bar on K16's are not going to last long.
I sustain 1.2 bar with my GIAC Stage 2... [/QUOTE
Sustained 1.2 bar on K16's are not going to last long.
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Well it actually causes a lot of issues. The first is it raises the deck height of the piston. If you ever have a chance to look at a carboned up piston sometimes they can become fairly thick. It only takes thousands to change the CR. The second issue is it does change the squish area and swirl thus creating a different burn. This is critical to efficiency of the chamber. Either one of these situations will cause higher knock activity which directly retards timing and changes maps. At 15K depending on the gas and driving you do the build up can be excessive. Again, many factors are involved. We have had issues with the 993 systems for years. ¼ and ½ inch inlets will carbon closed!
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Originally posted by GeorgeJ
Your car peaks at 1.2 bar at say around 5,000 rpms and continues to hold 1.2 bar until the 6,700 rpm redline, or
Your car peaks at 1.2 bar at say around 5,000 rpms and continues to hold 1.2 bar until the 6,700 rpm redline, or
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Originally posted by PorschePhd
Peaking and sustaining are two different things. All turbos surge. The level 4 file is designed to accommodate the surge then as the RPM comes up the system pulls back down. This would be the same adjustment you would make for timing or fuel adjustment on standalone air temp compensation. Never believe any boost gauge on the dash. It is a light show from the factory unless it is half of what it should be. 99ths of a bar will not show 1 bar. 1.119 will not show 1.2 bar. The gauge tested against a calibrated mechanical boost gauge has been as much as 12% off on some of the cars we have tested. So just because the system says one thing doesn’t mean that is what you are getting.
If you really want to know put a mechanical gauge on it. If you are looking for real numbers, baseline the car. Then once the mods are completed redyno the car. Talk is cheap and the butt dyno just doesn’t count. Proof is in the dyno and 2-6K rpm times on a sprint in a specific gear compared to a base line test or another car. This is your best bench mark. Not someone else’s dyno or a single dyno representing every car. This is why I have posted tons of dynos because each car will baseline different and end up with a different end number. The percentage of the gain are consistent. Deviances often are an issue of many factors including but not limited to cam timing (even though it is set there still is a deviances even in setting them) gas, carbon build up in the chamber causing a slightly raised CR, air flow, temperatures and so on. HP is not what wins the drag race folks, HP sells cars, TQ wins races. The ability to haul the car out of the way and push the air comes from TQ, the ability to maintain that speed comes from HP. It is not HP pushing you in the seat, that is TQ.
Peaking and sustaining are two different things. All turbos surge. The level 4 file is designed to accommodate the surge then as the RPM comes up the system pulls back down. This would be the same adjustment you would make for timing or fuel adjustment on standalone air temp compensation. Never believe any boost gauge on the dash. It is a light show from the factory unless it is half of what it should be. 99ths of a bar will not show 1 bar. 1.119 will not show 1.2 bar. The gauge tested against a calibrated mechanical boost gauge has been as much as 12% off on some of the cars we have tested. So just because the system says one thing doesn’t mean that is what you are getting.
If you really want to know put a mechanical gauge on it. If you are looking for real numbers, baseline the car. Then once the mods are completed redyno the car. Talk is cheap and the butt dyno just doesn’t count. Proof is in the dyno and 2-6K rpm times on a sprint in a specific gear compared to a base line test or another car. This is your best bench mark. Not someone else’s dyno or a single dyno representing every car. This is why I have posted tons of dynos because each car will baseline different and end up with a different end number. The percentage of the gain are consistent. Deviances often are an issue of many factors including but not limited to cam timing (even though it is set there still is a deviances even in setting them) gas, carbon build up in the chamber causing a slightly raised CR, air flow, temperatures and so on. HP is not what wins the drag race folks, HP sells cars, TQ wins races. The ability to haul the car out of the way and push the air comes from TQ, the ability to maintain that speed comes from HP. It is not HP pushing you in the seat, that is TQ.
Thank you for the detailed feedback. It is very helpful.
On the stage 4 cars you prepare, generally what peak boost reading are you seeing on the inaccurate factory light show? Also, how much does the boost pull back as the car approaches redline in the higher gears?
More importantly, how much rwhp does the race program normally generate over the stage 4 pump gas program? Is it mainly advance in timing or is there a boot increase as well?
Thanks
George
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