Another stage 2 P1X build in the books - time to wastegate?

[mangosmoothie]

I've been lurking the forums and figured it's time to introduce myself. I've had my Bullitt about 6 months now. Was looking for a PP1 or PP2 but the Bullitt was actually the best deal I could find at the time. She has some miles, 40k now.

Baselined 428 whp. Added a Stage 2 P1X (biggest pulley), Kooks 1 7/8 with green cats, Corsa X pipe. Tuned with UCal by Palm Beach. Made 628 whp on 91. An A10 stage 2 P1X with stock exhaust made 576 whp on the same dyno so I'm happy with where mine landed.

The dyno and tune were done at sea level. Unfortunately I spend a lot of time at high elevation (like 8k DA, it's bad).

Next on the list is to get a draggy and do some pulls at sea level, then at altitude. Compare the times and datalogs. If it's way slower (which I'm suspecting it will be) I'm considering a smaller pulley and wastegate. That way I get some more boost at altitude but don't overdo my fuel limitations back at sea level (both flow and octane). I know wastegate setups are a little controversial.... For my purpose and intent I think it's the best solution for now.

If anyone has better ideas.. I'm all ears.

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[LSchicago]

No need for a wastegate. Pulley down to a 4.5". That will get you 10psi. Shift at 7,000 instead of 7,500 when you are at low altitude. Bam, lower boost. Or get a fuel system with E85 and send it.

 

[80FoxCoupe]

Pulley down.

 

[SolarFlare]

you lost me at wastegate

 

[mangosmoothie]

No need for a wastegate. Pulley down to a 4.5". That will get you 10psi. Shift at 7,000 instead of 7,500 when you are at low altitude. Bam, lower boost. Or get a fuel system with E85 and send it.

No corn or else I would be on the sauce

 

[LSchicago]

No corn or else I would be on the sauce

You can still go with the 4.5" pulley, and shift no later than 7,000 when in lower elevations.

 

[mangosmoothie]

Sounds like the easiest plan. I like.

 

[fmc_smt]

Or pulley down further , I'm down the hill from you . On 4.0 right now runs strong .

 

[mangosmoothie]

so looks like it has a 4.63 pulley and a NBH 25080670HD belt.

Altitude loss is about 20%.

Current calc with 7.65 crank and 4.63 blower gives me ~53000 rpm at 8k

4.0 gives me ~62750 at 8k which is roughly 15% more rippems. I know it isn't linear but that seems like an ok ball park. Shifting at 7k gives 54800 so that should be fine back at sea level.

My short search says a 653 belt will work with a 4.0 pulley but idk if that's the same for a 15-17 and 18+

 

[Jackson1320]

I think for the car to feel the same at both altitudes what you are talking about doing is perfect

 

[DougS550]

I think for the car to feel the same at both altitudes what you are talking about doing is perfect

Are you Talking About A boost Controller Like this One for your Centri? Seems Like it would work

 

[LSchicago]

4.0 shifting even at 7,000 is pushing it on 91. Lund wouldn't tune on a 4.38 on my 18 with 93 octane. I am running a 4.0 on E85 now. 4.0 is roughly 14PSI at 7500 rpm. With crappy 91 octane you are asking for trouble. You might get by running Boostane to every tank.

 

[Jackson1320]

Are you Talking About A boost Controller Like this One for your Centri? Seems Like it would work

That would work fine but it can be done for a fraction of that

 

[DougS550]

That would work fine but it can be done for a fraction of that

Yep, it does sound expensive but, to quickly be able to change your boost levels electronically on a Centi is a plus for me. Plus for me, I just don't feel like reinventing the wheel all the time and just find myself paying more for mods already engineered. Good Luck with yours.

 

[Jackson1320]

Yep, it does sound expensive but, to quickly be able to change your boost levels electronically on a Centi is a plus for me. Plus for me, I just don't feel like reinventing the wheel all the time and just find myself paying more for mods already engineered. Good Luck with yours.

You can do the exact same thing with a bov and a boost controller. There are kits out for this. It’s called a torque booster

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