[ad1996]

Hey all, yesterday I got my VRSF Downpipes installed and ended up changing my car from Cobb Stage 1 Aggressive to Stage 2 Aggressive. After doing a some launches, I noticed that my boost peaked at 20.2 psi.. I did some reading on the map notes and saw that for Stage 2 Aggressive the peak boost should be 14.5 and taper down from there. Not sure if I should be worried but I do think that 20 psi is a little too high for stock turbos to be putting out.

On another note, I'm about to install my Intercooler and start running Stage2+FMIC Aggressive and wanted to know what exactly the difference in power is between Stage 2 Aggressive and Stage 2+FMIC Aggressive. Any help will be much appreciated!!

[chepy24]

its just a boost spike you're good

[chepy24]

to answer your second part... youll notice you keep the power in the upper rpm. the car wont just die. and you will be able to put the same power down after multiple runs it wont heat soak like the stock ones

[ad1996]

Originally Posted by chepy24

to answer your second part... youll notice you keep the power in the upper rpm. the car wont just die. and you will be able to put the same power down after multiple runs it wont heat soak like the stock ones

so basically more sustained boost? instead of tapering down?

[Jklad]

Originally Posted by ad1996

so basically more sustained boost? instead of tapering down?

By tapering down he means you will not get the timing drops in the upper rpm range that occur due to heat soak as you climb rpm

[chepy24]

Originally Posted by Jklad

By tapering down he means you will not get the timing drops in the upper rpm range that occur due to heat soak as you climb rpm

^^^^ this

[Jeff@TopGearSolutions]

Boost is measured pre throttle body. Therefore any over-boost will result in throttle closure.

As the throttle blade closes it creates turbulence which incorrectly reads a higher boost number then what the real boost is in the manifold/engine.

I'm surprised there isn't a sticky on this but the only real boost measurement should be read in the intake manifold and that would require a secondary gauge.

The only time the boost measurements are correct from the electronic readout are when the throttle blade is open 100%.

When reading your boost numbers, always compare them to your throttle position. If the throttle position is partially closed the boost reading will be artificially inflated.

[WedgePerformance]

Just a minor clarification as I made the same assumption prior to having this issue... boost means (abs) is measured pre-throttle body, boost is measured post throttle body. You can run 21.8 psi boost means (abs) @ 33% throttle and boost will read 18.3 psi. Req boost means (abs) has nothing to do with actual boost pre or post throttle body. I have logs to back this up.

Originally Posted by Jeff@TopGearSolutions

Boost is measured pre throttle body. Therefore any over-boost will result in throttle closure.

As the throttle blade closes it creates turbulence which incorrectly reads a higher boost number then what the real boost is in the manifold/engine.

I'm surprised there isn't a sticky on this but the only real boost measurement should be read in the intake manifold and that would require a secondary gauge.

The only time the boost measurements are correct from the electronic readout are when the throttle blade is open 100%.

When reading your boost numbers, always compare them to your throttle position. If the throttle position is partially closed the boost reading will be artificially inflated.

[Jeff@TopGearSolutions]

Originally Posted by WedgePerformance

Just a minor clarification as I made the same assumption prior to having this issue... boost means (abs) is measured pre-throttle body, boost is measured post throttle body. You can run 21.8 psi boost means (abs) @ 33% throttle and boost will read 18.3 psi. Req boost means (abs) has nothing to do with actual boost pre or post throttle body. I have logs to back this up.

That's an excellent clarification and good to know.

[WedgePerformance]

Originally Posted by Jeff@TopGearSolutions

That's an excellent clarification and good to know.

I couldn't believe it at first. It was an o-schits moment to see throttle close to control boost. Granted we don't have that issue anymore as we're able to boost to 20 psi now without throttle closer. Although, our new boost curve is a thing of beauty.

[Greatdane84]

I can't believe you havent done the FMIC yet! I was running stg 1+ down here in Florida for oh... I don't know 3 redlines before pulling the trigger on mine. I'm sure your location plays a huge factor but down here in Florida the car would heatsoak very quickly. After 7" FMIC I've never seen the oil temp over 250ish

[ad1996]

Originally Posted by Greatdane84

I can't believe you havent done the FMIC yet! I was running stg 1+ down here in Florida for oh... I don't know 3 redlines before pulling the trigger on mine. I'm sure your location plays a huge factor but down here in Florida the car would heatsoak very quickly. After 7" FMIC I've never seen the oil temp over 250ish

Yep I'm in Florida as well, just never drove my car that hard so didn't need it, now I'm trying to squeeze out more power and will end up needing it haha

[Tiago@VRSF]

Originally Posted by WedgePerformance

Just a minor clarification as I made the same assumption prior to having this issue... boost means (abs) is measured pre-throttle body, boost is measured post throttle body. You can run 21.8 psi boost means (abs) @ 33% throttle and boost will read 18.3 psi. Req boost means (abs) has nothing to do with actual boost pre or post throttle body. I have logs to back this up.

Good to know!