T-78 Boost Pattern?
T-78 Boost Pattern?
Is this the normal T-78 boost pattern with a 10 psi w/g spring?
RPM PSI
2500 .45
3000 2.50
3500 4.40
4000 6.40
4500 8.70
5000 9.00
5500 9.40
6000 9.40
6500 10.0
7000 10.0
7500 10.05
8000 10.0
8500 10.0
RPM PSI
2500 .45
3000 2.50
3500 4.40
4000 6.40
4500 8.70
5000 9.00
5500 9.40
6000 9.40
6500 10.0
7000 10.0
7500 10.05
8000 10.0
8500 10.0
Hey cris,
been a long time. those #'s seem a little laggy, I would imagine that the T78 should see 10psi at around 3700rpm instead of 4500rpm.
been a long time. those #'s seem a little laggy, I would imagine that the T78 should see 10psi at around 3700rpm instead of 4500rpm.
Originally Posted by crispeed
Is this the normal T-78 boost pattern with a 10 psi w/g spring?
RPM PSI
2500 .45
3000 2.50
3500 4.40
4000 6.40
4500 8.70
5000 9.00
5500 9.40
6000 9.40
6500 10.0
7000 10.0
7500 10.05
8000 10.0
8500 10.0
RPM PSI
2500 .45
3000 2.50
3500 4.40
4000 6.40
4500 8.70
5000 9.00
5500 9.40
6000 9.40
6500 10.0
7000 10.0
7500 10.05
8000 10.0
8500 10.0
Originally Posted by pluto
Hey cris,
been a long time. those #'s seem a little laggy, I would imagine that the T78 should see 10psi at around 3700rpm instead of 4500rpm.
been a long time. those #'s seem a little laggy, I would imagine that the T78 should see 10psi at around 3700rpm instead of 4500rpm.
Yeh that's what I thought also. The owner had it rebuilt so I guess it probably was not done right. I'll have to take it off the car and check. Also I increased the boost to 14 psi and only made 40hp over what it did at 10 psi which was 328rwhp. At 14psi it should at least be in the low 400's not 360 hp.
I usually see around 315-335rwhp at 10psi with the T78 and 360-390rwhp at 14psi. It all depends on the entire system. intake, exhaust, i/c. Check his double throttle and see if they're fully open. That's a good 20-40rwhp right there if they're closed....
Originally Posted by crispeed
It's been too long!
Yeh that's what I thought also. The owner had it rebuilt so I guess it probably was not done right. I'll have to take it off the car and check. Also I increased the boost to 14 psi and only made 40hp over what it did at 10 psi which was 328rwhp. At 14psi it should at least be in the low 400's not 360 hp.
Yeh that's what I thought also. The owner had it rebuilt so I guess it probably was not done right. I'll have to take it off the car and check. Also I increased the boost to 14 psi and only made 40hp over what it did at 10 psi which was 328rwhp. At 14psi it should at least be in the low 400's not 360 hp.
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