SLOW BOOST...Are my turbos mismatched?
11-13-2010, 02:52 PM
#22
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IM thinking my turbos are too big. Took the car to the track today.....Same thing...Ran 11.55 at 130mph...Boost is still not strong until late in the RPM Range. It's acting like a huge single turbo car. When it finally hit's full boost at 5000 rpm it pulls like an SOB. Im wondering if it is just the fact that these turbos may be too much for my 370ci. The exhaust housings are .68 each but wondering if the compressor housings are just too big. let me know what you think.
11-16-2010, 07:31 AM
#24
What boost level to go 130? Unless the car is over 4000lbs 130 is a little slow for 800whp.
If its a low boost level and the gates are cracking that is normal to see boost come on late, especially with the combination.
A boost controller keeping them closed up will help a lot. Also what kind of timing and AFR coming into boost?
If its a low boost level and the gates are cracking that is normal to see boost come on late, especially with the combination.
A boost controller keeping them closed up will help a lot. Also what kind of timing and AFR coming into boost?
11-16-2010, 08:13 AM
#25
If these are front mounted, imho they should be fine. Have you check for boost leaks with a regulated compressor? I would check cold and hot side. Pull the valve covers and loosen the rockers so you can check the complete system, cold/hot side. Those 66's up front should spool plenty fast. Best of luck. p.s.... do you have fresh plugs in it? if you have weak/hurt plugs, it will kill spool
11-16-2010, 09:15 AM
#28
A AFR 8019 spring is damn near identical in spring pressures to a PRC Extreme.
PRC Extreme:
Spring Pressure Closed: 155 lbs. @ 1.800"
Spring Pressure Open: 410 lbs. @ 1.140"
Coil Bind: 1.090"
AFR 8019:
Spring Pressure Closed: 155# @1.810
Spring Pressure Open: 412# @ 1.210
Coil Bind: 1.080"
Not sure what comes standard on AFR's but I have always chose to get the better spring.
11-16-2010, 11:02 AM
#30
check for leaks with a compressor @15#s. check around the injectors, iac valve, throttlebody flange ect. any can be leaking, and even a few could be leaking a tiny bit.
11-16-2010, 11:08 AM
#31
also, alotta times im seeing ppl use arp head studs, and they usually dont clear on some of these aluminum intakes. the top row of small studs that are supposed to fit under the intake between the ports, actually stick out further that the intake surface. stock intakes aernt solid in that area, but most of the aluminum intakes are.
11-16-2010, 08:11 PM
#32
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What boost level to go 130? Unless the car is over 4000lbs 130 is a little slow for 800whp.
If its a low boost level and the gates are cracking that is normal to see boost come on late, especially with the combination.
A boost controller keeping them closed up will help a lot. Also what kind of timing and AFR coming into boost?
If its a low boost level and the gates are cracking that is normal to see boost come on late, especially with the combination.
A boost controller keeping them closed up will help a lot. Also what kind of timing and AFR coming into boost?
11-16-2010, 08:13 PM
#33
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If these are front mounted, imho they should be fine. Have you check for boost leaks with a regulated compressor? I would check cold and hot side. Pull the valve covers and loosen the rockers so you can check the complete system, cold/hot side. Those 66's up front should spool plenty fast. Best of luck. p.s.... do you have fresh plugs in it? if you have weak/hurt plugs, it will kill spool
11-16-2010, 08:15 PM
#34
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also, alotta times im seeing ppl use arp head studs, and they usually dont clear on some of these aluminum intakes. the top row of small studs that are supposed to fit under the intake between the ports, actually stick out further that the intake surface. stock intakes aernt solid in that area, but most of the aluminum intakes are.
11-17-2010, 09:46 AM
#35
loosen the rockers to close the valves, plug off the turbo air inlet (i used 4" pvc plug) and install a fitting on the end so you can hook up a compressor air hose. Set your regulated air to 15 pounds or so and listen for leaks. You can also check the hot side using the same technique. I think you will be surprised how much air a small leak can produce. Best of luck.
11-17-2010, 08:26 PM
#37
its pretty hard to notice, they just barely stick past the head surface, i know the bbk's dont clear. but yes, they defanitly will leak
11-17-2010, 09:42 PM
#39
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Ok...thanks for doing some research for me.....I am going to go to lowes friday and buy the supplies to make a leak tester with valve stems and a pressure gauge so I can fill the system and then listen for leaks.
11-19-2010, 04:32 PM
#40
this is your best bet. check injectors, map sensor, throttlebody, ect. soapy water in a spray bottle. clean it up and check for leaks at the same time lol