Piper 300 - full T25 - C1J combo

[olidaviesuk]

Hi All,

Just wondering if anybody has run the above as a replacement after running the 285 and if you saw much difference on the dyno, I'm assuming you'd probably see some gains in torque but nothing beats real world experience.

Cheers

Oli

[newbstar*]

Rollerbearing t25 would be the way to go! I like t28rb and vnt. Had them all;)
Start off by looking at compressor maps, or talk to adam l.

[Scoff]

It'll be the other way around. The BP300 doesn't make much in the way of peak torque. It also isn't all that great at dealing with high boost (20+psi). I wouldn't expect to see any more peak power from it either, it might just move things up the RPM range a bit. It's longer and smoother torque curve might be usefull on the track ?

[Sparkie]

i once did a piper 300 with a piper 285's lift.
piper know it as a piper 1011, was pretty lumpy - but i did get it ground at 108deg...

[olidaviesuk]

Thats really interesting to hear Scoff - although should have guessed that myself what with the 300 having almost 1mm less lift :crap: we're really stuck with turbo size and boost level (restrictors and one type of turbo - which already is effectively a rollerbearing T25) the longer smooth torque curve would be a definite advantage on track - although not at the expense of outright bhp. :D

Have tried cams with lots of lift (11.5mm) and about the duration of the 300, but whilst they work with big turbos running lots of boost, the T25 can't shift enough air at the boost levels we are stuck with to get anywhere with them - atm we are in the region of 215+ @ relatively low boost levels (well around 1bar anyway) so getting near the limit of what can be done without efi, but as they say every little helps.

Sparkie > I like the sound of your custom grind - what sort of boost/power/torque did you get with it? was that on a full T25?




It'll be the other way around. The BP300 doesn't make much in the way of peak torque. It also isn't all that great at dealing with high boost (20+psi). I wouldn't expect to see any more peak power from it either, it might just move things up the RPM range a bit. It's longer and smoother torque curve might be usefull on the track ?

[Alastair]

Are you running standard fuel or race fuel?

[olidaviesuk]

Standard fuel.... If it was race fuel would be a different ball game...
Are you running standard fuel or race fuel?

[Alastair]

Standard fuel.... If it was race fuel would be a different ball game...

What boost are you limited to? And how do they measure it ;)

Are you on a 34mm intake restrictor?

I assume the regs haven't changed and you are limited to a Tomcat blower?

Sounds like you are making really good numbers at that boost on standard fuel ;) :agree::agree::agree:

[olidaviesuk]

Will pm you the finer details Ali... Regs are more or less the same though still stuck with the T25, yep Matt puts a very, very nice engine but always chasing more and more power ;)


What boost are you limited to? And how do they measure it ;)

Are you on a 34mm intake restrictor?

I assume the regs haven't changed and you are limited to a Tomcat blower?

Sounds like you are making really good numbers at that boost on standard fuel ;) :agree::agree::agree:

[Sparkie]

Sparkie > I like the sound of your custom grind - what sort of boost/power/torque did you get with it? was that on a full T25?

it was along time ago, i did the same cam for a few people round here, it had a long torque curve, it was far more revvy than a 285. i think the 108 lobe angle might have given too much overlap - it was on a t28/t25 btw.

[m1n1 (Jasper)]

New poster! (less than 10 posts)

I've got a piper 300 together witH a T3/T25 Hybrid running at 19 psi above the throttle valve (1,3 bar) and a Group A carb.
It really needs it's revs as you can see in the picture from the dyno last saturday....

http://i83.photobucket.com/albums/j320/joke221/dyno%2024%20maart%202012/Jasper5GTTGrpAcarbCam300deg.jpg

[Dave Reed]

Your afr's are quite high on that run (13's) .. Have you adjusted your carb since?

[m1n1 (Jasper)]

New poster! (less than 10 posts)

Your right it's quite high.
I haven't changed it it yet but I plan to put a bigger main jet in this week after our dutch MOT...

[Markey Mark (BD)]

New poster! (less than 10 posts)

Your right it's quite high.
I haven't changed it it yet but I plan to put a bigger main jet in this week after our dutch MOT...

Best advice mate is to ditch the larger venturi body and fit a standard one, i would advise modifying the enricment jets too and not just stick a larger main jet in there not really the best way to fuel the carb really

[m1n1 (Jasper)]

New poster! (less than 10 posts)

I've already made the air correction jet smaller and the stage 2 jet bigger. I will try to get the AFR around 12.5 at WOT
Found a lot of info about the solex on the site here :agree:

[olidaviesuk]

Nice even power and torque curves! Would have thought you would have made a little more power at that boost level - especially since its running that lean. Looks like it pays to have that extra lift from the 285.

You've got a nasty little lean spike at around 4500 on the AFR - a little work with the second stage would probably help that a bit - sounds like you're already got those mods worked out though! :agree:


New poster! (less than 10 posts)

I've got a piper 300 together witH a T3/T25 Hybrid running at 19 psi above the throttle valve (1,3 bar) and a Group A carb.
It really needs it's revs as you can see in the picture from the dyno last saturday....