2.9 whipple 2.80 stock lower 100 mm belt?

[jon henry]

Hey there I have a 2.9 Whipple now with a 3.50 pulley on a 76 inch belt with no Auxilary idler yet. I have a 100 mm idler. First question is what is the consencus on what you add for belt length to put a 100 mm auxilary idler on there? 2nd question, what belt for all stock idlers with the 100 mm auxilary with a 2.80 upper and Stock lower? Just trying to save myself from buying anymore belts. I am at 4 now and 1 should work. Anyone running a 2.80 with stock size idlers with a 100 mm upper idler? What belt and tensioner notched or not? Thanks in advance for an help...

Jon

 

[jon henry]

Anyone? I know there is some Whipple 2.9 guys out there...

 

[1320 Junkie]

k080751 for the 2.8 k080765 for 3.5 and aux idler....u may have to knock the tab out of the tensioner though. Hope you know the 2.8" will make 25psiand u will have spark issues...our stock ignition systems cant handle more than 23-24psi cleanly...im @ 3.0" (23psi) upper for my race tune and easily over 700+ hp...enjoy.

 

[jon henry]

Are you at sea level? I am only seeing 15-16lbs out fo my 2.9 at 4400 ft in the air. I DO have a 3.10 upper pulley, But I think for me to get to 21-22ish I am going to need the 2.80 upper. I tell you tonight my 3.10 rr is here...

Jon

k080751 for the 2.8 k080765 for 3.5 and aux idler....u may have to knock the tab out of the tensioner though. Hope you know the 2.8" will make 25psiand u will have spark issues...our stock ignition systems cant handle more than 23-24psi cleanly...im @ 3.0" (23psi) upper for my race tune and easily over 700+ hp...enjoy.

 

[1320 Junkie]

O

Are you at sea level? I am only seeing 15-16lbs out fo my 2.9 at 4400 ft in the air. I DO have a 3.10 upper pulley, But I think for me to get to 21-22ish I am going to need the 2.80 upper. I tell you tonight my 3.10 rr is here...

Jon

Yes I am at sealevel . My tuner pulled my car on the dyno to 6700 and he said he saw 19psi out of the 3.5 but the most I seen on the street was 18 @ 6300 where I shift and our stock valves don't float. Right now most I see is 17psi because of the summer heat and humidity....so all things being equal u will prob see 23psi with the 2.8 and 19 with the 3.1". Keep us posted how u make out.

 

[jon henry]

Got a 3.20 RR had to put it on and see what boost it would make. Seems like it holds 18 and spikes to 19 with the 3.20. Do you think I need about a 3.00 to see 20-21 lbs at my elevation? Speaking of elevation it does not seem to be making much of a difference on the boost levels advertised. Going .30 smaller I got about 2-2.5 lbs more boost.

Jon

P.S. Thanks Blown04 you have really helped me out alot...

Jon