Andy's HPF Stage 3 "SLEEPER VERSION" w/833rwhp SAE on Race+Meth

Andy wanted the big power of the stage 3 but without the loud 4" exhaust that comes with the stage 3 kit. So we ran the HPF Stage 3 on his car with an HPF Stage 4 FMIC, open dump stage 1 downpipe paired with the BMW midpipe and an HPF Titanium exhaust. The motor was built with the added strength of the HPF sleeved block which is now in quite a few M3s today including the new HPF Track motor.

The power in this car is amazing. It pulls like a runaway freight train but is still pretty quiet. No droning and yet it makes even more than the standard HPF Stage 3 stuff. Exciting stuff. Congrats Andy. I can't wait for you to feel the power!!



Chris.

nice runs, thanks for posting with 0 smoothing.

so the hpf titanium exhaust is a bit quieter than the stage 3? I like quiet

Originally Posted by Hobbit382

nice runs, thanks for posting with 0 smoothing.

so the hpf titanium exhaust is a bit quieter than the stage 3? I like quiet

the titanium exhaust pairs up with the stock midsection, the hpf stage 3/4 exhaust is a 4 inch all the way back

Originally Posted by Ky///m3

the titanium exhaust pairs up with the stock midsection, the hpf stage 3/4 exhaust is a 4 inch all the way back

good to know, is it listed on their site yet?

Originally Posted by Hobbit382

good to know, is it listed on their site yet?

i just looked at the main HPF turbo m3 page and did not see where it listed the difference. it only shows the stage 3/4 exhaust setup, not the HPF ti exhaust for the stock mids

Wow that is quiet, make me want another HPF M3

Originally Posted by mtran850

Wow that is quiet, make me want another HPF M3

Not trying to derail the thread but mytran, what's your vette putting down?

If anyone wants a loud 4" HPF exhaust (Lawrence edition with 3 resonators) I'm thinking about selling mine...PM offers.

Two of the resonators don't really count they're Vibrant Race Resonators only like 3" a piece. The main Vibrant resonator is about a foot. It has a lower tone than the standard HPF 4" exhaust; more growl like a V8...has more drone in my opinion. I wear earplugs after 15minutes...sounds wicked around town; not so great for long drives. Also one exhaust ticket...not buttering it up this exhaust sounds wicked but there are drawbacks.

Originally Posted by Ky///m3

Not trying to derail the thread but mytran, what's your vette putting down?

505 whp with just some bolt on and a Tune, it will be TT in a couple of months unless I decided to build a E92 M3 DCT

So, why have a Stage 3 and a 4 inch exhaust? Perhaps only under the most extreme builds or simply wanting the nioise all the time.

The numbers are too good not to go this way of the sleeper exhaust in almost all cases. An on demand exhaust cut out can always be added for what ever reasons. Sounds like best of all worlds.

Chris, how would the car sound by substituting a Borla V2 Mid pipe(deeper tone?) Will that flow as well or better than the OEM STOCK SECTION? What about no mid pipe? Would it drone with no mid pipe?

Nice results. I am looking for the same power range when I upgrade to PT71 and maintaining my stock exhaust system.

Looking good!

Originally Posted by mike@maximumpsi

Looking good!

Thanks Mike.

Originally Posted by ST06M3

Nice results. I am looking for the same power range when I upgrade to PT71 and maintaining my stock exhaust system.

It's nice to know the stock dual exhaust system design can flow this much. Make sure you run a high flowing exhaust though. We've found over 60rwhp differences between exhaust systems at these power levels!

Chris.

Originally Posted by Bdave

So, why have a Stage 3 and a 4 inch exhaust? Perhaps only under the most extreme builds or simply wanting the nioise all the time.

The numbers are too good not to go this way of the sleeper exhaust in almost all cases. An on demand exhaust cut out can always be added for what ever reasons. Sounds like best of all worlds.

Chris, how would the car sound by substituting a Borla V2 Mid pipe(deeper tone?) Will that flow as well or better than the OEM STOCK SECTION? What about no mid pipe? Would it drone with no mid pipe?

I believe we did a car with the Borla exhaust system and it was down 60rwhp over the HPF titanium. My guys can correct me if I'm wrong on that one.

Chris.

Originally Posted by HPF Chris

I believe we did a car with the Borla exhaust system and it was down 60rwhp over the HPF titanium. My guys can correct me if I'm wrong on that one.

Chris.

Well, I got the Agency Power muffler(bought strictly because HPF recommends this muffler), not Borla. I am debating on what mid to run on my home grown sleeper exhaust:
1)no mid pipe
2) OEM mid(I still have mine) . could drone be further reduced by using the Borla mid pipe?
3) the Borla V2 mid. The car always ran great with that Borla V2 mid, nice tone too. Its volume is a good bit larger than OEM.
I dont know what the inside of the Borla mid looks like. AFAIK, its pretty nonrestrictive and eliminates any trace of rasp. I hate rasp. I never cared for their muffler at all. Maybe the power was lost in the muffler, not the v2 mid pipe. It might be worth a listen. Its still installed, BTW. THats a major point.

Besides, the car will be tuned for max HP in the track mode with the cut out in the OPEN position...ie overboard dump.

Chris, any way you slice it, this sleeper system is an huge winner. Well done!

We actually got the biggest gains I have seen (from exhaust change) on a Stage 2 car we had come through here about a month or two ago.. He had a full Magnaflow exhaust and made about 520whp on Pump and Meth... Well when we switched him over to the AP Mid-Pipes and AP Rear Section he made about 580whp with no change in the tune at all. I will try and find the Dyno sheets for this tomorrow. There might be a thread on this already....

I believe my Eisenmann exhaust was the exhaust with the lowest numbers. Not very good on a FI M3.

Originally Posted by HPF Kirk

We actually got the biggest gains I have seen (from exhaust change) on a Stage 2 car we had come through here about a month or two ago.. He had a full Magnaflow exhaust and made about 520whp on Pump and Meth... Well when we switched him over to the AP Mid-Pipes and AP Rear Section he made about 580whp with no change in the tune at all. I will try and find the Dyno sheets for this tomorrow. There might be a thread on this already....

borla is even more restrictive then the magnaflow, much more restrictive then all oem factory and factory muffler.

I added more pics of Andy's car to the first post.

I had the Eisemann sport. HPF said my car dynoed lower then everyone and asked if they could try different exhaust setups. What they found were stock was 10rwhp higher then the sport and the AP was 20 rwhp more