Most powerfull Boxster engine

[Gary in BR]

Hello,

After reading about the GT3 powered Boxster in Austraila it got me thinking...
what are the numbers on the high power boxsters out there.

Mine is a 2.5 and has about 270 hp based on the dyno and rough math. Mine I guess is not a "high" power Boxster, but remember stock its only 201hp and has the lowest gear ratios of any Boxster. The gear ratio is based on my bad memory I am sure someone here and confirm or dispell this.

Josh I think you are over 300hp. Is that close?

Boost, PK and Jacques what do you guys think your power will be when you are done?

[blinkwatt]

I think tholyoak is running one of the most powerful Boxster out there.......x51 3.6L.

I bet that thing is stupid fast.

[boostiality]

Gary

Not sure how much mine will be. If there was any sort of prediction I can possibly give it would be one from a similar motor, based from displacement and compression which is a 3.0 2jzge that was turbocharged. They have more displacement but less compression and also a more archaic design. That particular motor made 30rwhp on 2 psi completely untuned, 91 octane and intercooled. My wastegate spring is set at 3.5 psi, is also intercooled, and I'll be on 93.xx octane.

Wasn't there that character in Europe who a very powerful twin turbo boxster? Something in the mid 350rwhp range. Also those guys' who do the GT1 based motor swaps ala GT3 or TT.

[JP-s-in st. louis]

Gary

I am @ 285WHP and 345 at the crank on a Mustang dyno. Some will say that it does not matter what dyno says what, we all should know that is wrong. After I finish the suspension this next week here is a short list of my next few mods; Cat Bypass pipes (if I can find anyone that will make it), Schrick Cams, Head work looking for a set now to get ported and polished and I may try to see if I can do the GT3 crank like Markski in his 996TT. Oh and an IC when/if iA does finish it up. At that point I can run more boost. :dance:

Now Dave on 6 speed had FVD do a 3.8 transplant. I have the dyno sheet somewhere and IIRC 360 crank

[JP-s-in st. louis]

My project had been on hold for the last year or so but now I am ready to get back after it. I WILL have the most powerful 986 Boxster in the country again by the end of the year.

[986speedster]

Wow JP, some statement!!! But it's guys like you, Gary, and BOOST that push the limits of technology that help the regular guys out. I'm sure there are alot of guys here and 6speed who appreciate all the write ups you guys do. I know I do, and hopefully start with my motor/exhaust mods.

[Gary in BR]

Originally Posted by JP-s-in st. louis

Gary

I am @ 285WHP and 345 at the crank on a Mustang dyno. Some will say that it does not matter what dyno says what, we all should know that is wrong. After I finish the suspension this next week here is a short list of my next few mods; Cat Bypass pipes (if I can find anyone that will make it),



Are your plans to bypass all the cats? What sort of gains do you think you will make.



Schrick Cams,

What sort of gains will theses cams give you and what about the ECU? Will you have to reprogram the ECU with new cams?


Head work looking for a set now to get ported and polished and I may try to see if I can do the GT3 crank like Markski in his 996TT.


Again, what will the GT3 crank do for our cars and can these mods work on a 2.5?


Oh and an IC when/if iA does finish it up. At that point I can run more boost. :dance:



Now Dave on 6 speed had FVD do a 3.8 transplant. I have the dyno sheet somewhere and IIRC 360 crank

With these mods you may be over 400 crank.
That may put you at the most powerful Boxster...good luck.

[boostiality]

Originally Posted by JP-s-in st. louis

Gary

I am @ 285WHP and 345 at the crank on a Mustang dyno. Some will say that it does not matter what dyno says what, we all should know that is wrong. After I finish the suspension this next week here is a short list of my next few mods; Cat Bypass pipes (if I can find anyone that will make it), Schrick Cams, Head work looking for a set now to get ported and polished and I may try to see if I can do the GT3 crank like Markski in his 996TT. Oh and an IC when/if iA does finish it up. At that point I can run more boost. :dance:

Now Dave on 6 speed had FVD do a 3.8 transplant. I have the dyno sheet somewhere and IIRC 360 crank

Correct me if I'm wrong, but I thought our M96 motors have no interchangeable parts to the GT1 block?

Do you mean like putting the M96 3.8 crank into your more? Stroker boxster would be pretty cool.

[2000SoCalBoxsterS]

Originally Posted by JP-s-in st. louis

Gary

I am @ 285WHP and 345 at the crank on a Mustang dyno. Some will say that it does not matter what dyno says what, we all should know that is wrong. After I finish the suspension this next week here is a short list of my next few mods; Cat Bypass pipes (if I can find anyone that will make it), Schrick Cams, Head work looking for a set now to get ported and polished and I may try to see if I can do the GT3 crank like Markski in his 996TT. Oh and an IC when/if iA does finish it up. At that point I can run more boost. :dance:

Now Dave on 6 speed had FVD do a 3.8 transplant. I have the dyno sheet somewhere and IIRC 360 crank

JP, Fabspeed has CAT ByPass pipes. Wouldn't they work for you?

[JP-s-in st. louis]

Gary

Correct at that point I will have no cats. I have seen the Fabspeed and for 500 bucks , I think if I can take the time I can have a set fab'd up and cost less then half that amount.

No extra ECU tunning will be needed for the CBP. As for HP I would expect 5-10 max.

The GT3 Crank was modified on a few of the Protomotive BIG build TT's along with CJV to achieve 9K RPM redline. At that point a full rebuild may be needed. The crank is just an idea as of now and I would have to speak with Tod d Z first.

FVD has a set of 3.8 heads on sale right now. I am curious if these will work on the 3.2. My learning curve and this project will continue to be a work in progress.

I know who all to go to for all this project except the person to finance it. The suspension is getting VERY expensive.

Josh

[boostiality]

Originally Posted by JP-s-in st. louis

The GT3 Crank was modified on a few of the Protomotive BIG build TT's along with CJV to achieve 9K RPM redline. At that point a full rebuild may be needed. The crank is just an idea as of now and I would have to speak with Tod d Z first.


Josh

Josh

Since it doesn't look like the motors are gaining displacement, what positive aspect does the GT3 do compared to the TT? I'm pretty sure they both use the same crank, I just curious what their telling people on the reason why.

Joe

[tholyoak]

The GT3 cars and turbo cars use an engine based upon the old 964/993/GT1 engine. These cranks will not swap into an M96 based motor.

Todd

[boostiality]

Originally Posted by tholyoak

The GT3 cars and turbo cars use an engine based upon the old 964/993/GT1 engine. These cranks will not swap into an M96 based motor.

Todd

Whats up Todd

Can different M96 rotating assemblies be swapped? Like say a 3.6 crank, rods, pistons go into a 2.7 motor ( I mean if we were to bore out the cylinders to accept the pistons) ?? . I'm guessing the motor would be choked up because of the cams and heads though

Joe

[tholyoak]

Joe,

I'm not 100% sure but at least within the same design years I would guess that the journal diameters are the same. You are correct though, the top end would need modification to deal with the larger bottom end. This is why I think it would be cheaper and easier to just start with the bigger motor rather than try and build up a smaller one. Custom engine work isn't cheap and all things considered, crate engines from Porsche are.

Although if you built up a 2.5 or 3.4 into a 3.6/3.8/4.0, you wouldn't have to deal with the electronics issues that can complicate some engine conversions. Problem is you then open up a new can of worms as far as needing custom ECU programming that wouldn't be cheap to do correctly.

Also, a large amount of the difference between the 3.4 swap that was in my car and the subsequent 3.6 engines I have had in the same car comes not from the displacement increase, but the significant torque improvements from the increased cam timing changes that came with the variocam plus system over the basic variocam setup (40 degrees vs 25 degrees if I remember correctly). You wouldn't get this benefit if you modified an earlier motor.

Just my $0.02.

Todd

[JP-s-in st. louis]

Thanks for the info Todd now back to the old drawing board.