Since the T-Rex in-line pump provides 50 gph @ 70 psi

WALBRO PUMP DATA

GSS242					GSS307					GSS340
190 lph					255 lph					255 lph
12.0V		13.5V		Current Draw	12.0V		13.5V		Current Draw	12.0V		13.5V		Current Draw
PSI	GPH	PSI	GPH	amps	PSI	GPH	PSI	GPH	amps	PSI	GPH	PSI	GPH	amps
0	56	0	64	3.1	0	75	0	83	5.5	0	75	0	83	4.9
10	52	10	61	3.6	10	72	10	81	5.8	10	72	10	81	5.2
20	48	20	57	4.1	20	67	20	77	6.7	20	68	20	77	6.1
30	44	30	53	5.0	30	63	30	72	7.7	30	63	30	73	7.0
40	40	40	50	5.8	40	58	40	68	8.8	40	59	40	69	8.0
50	36	50	46	6.7	50	54	50	64	9.9	50	56	50	65	9.0
60	32	60	43	7.5	60	49	60	58	10.9	60	52	60	61	10.1
70	28	70	39	8.4	70	40	70	51	12.0	70	48	70	57	10.6
80	22	80	32	9.3	80	29	80	39	13.2	80	43	80	52	11.1
90	12	90	23	10.2	90	0	90	12	14.5	90	36	90	45	11.6
100	2	100	15	11.5						100	27	100	38	13.5
110		110	0	12.6

Both the GSS307 and the GSS340 pumps are rated at 255 liters/hr @ 45 psi (65 gal/hr @ 45 psi). Above 70 psi, the GSS340, still provides flow, while the GSS307 drops off significantly. If you run normally aspirated, your fuel pressure regulator is set at about 40 psi, which is the same flow rate for both pumps. If you are running a supercharger and FMU, the pressure will need to increase well above 70 psi when under boost, and the GSS340 would be a better choice.

Revised: September 22, 2001 09:01 PM