THE 3.2
To help our customers better understand our products and choices, we run thousands of dyno tests on the Shelby’s,
sometimes in 1 psi increments on the engine, chassis and supercharger dynos. We recognize that the trend is toward more
efﬁcient and/or larger displacement Ford engines along with the engine builder advances. To keep pace with their higher
HP and RPM levels, we upgrade our base kits to larger superchargers and inlet systems. Our goal, as always, is to offer kits
that make more HP than our competition and the OEM superchargers. The new 3.2 is an example.
5.8 vs. 5.4 BOOST
The larger displacement 5.8 engine see 2 psi less boost at 6300 (rev limiter) but makes it back by 7000 so both develop a
“peak” boost of 17.5. Therefore, we rate both engines at the same “peak” boost. The larger 5.8 developed more HP in stock
form so it will produce more HP when supercharged to the same boost. All tests are SAE. The rarely used STP calibration is
2% higher and EHP is approx. +15%.
SHELBY GT500 2.8, 3.2 BOOST, HP, PULLEY RATIO, RPM
PULLEY
4.00
3.87
3.75
3.50
3.25
3.00
2.75
2.50
corelﬁles\techshelby28-32boosthp.cdr 03/18/2015
3.2 5.4
2.8 5.4
2.8 5.8
7.1” CRANK
6300 RPM
6300 RPM
7000 RPM
HP
BOOST
HP BOOST
HP BOOST
RATIO
710
15.5
627 13.5
628 17.5
730
2.02
13.5
658 15.5
679 20.0
744
2.18
15.5
782
2.36
692 18.5
714 22.0
18.0
840
2.58
23.0
794 21.0
779 24.0
883
2.84
25.0
845 23.5
842 26.0
3.2 5.8
7000 RPM
BOOST
HP
15.5
712
17.5
732
20.0
764
22.0
802
24.0
860
26.0
904