Stock 4.8 802RWHP but valve float now
05-13-2014, 09:11 AM
#81
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07-16-2014, 02:23 PM
#83
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Wow that's moving. I had a 3.8 Buick with a 68mm turbo in my nova and with a dusty spec'ed 9.5 for 10.0 in the 135mph range.Worked perfect with the v6. Well I put a 6.0 in it and the convertor was way too loose and the data log showed it was running thru the whole quarter mile higher in rpms than where the bone stock motor made its best power and the slippage calcs were similar to yours. I sent it back to Dusty and he tightened it up for me and now the slippage calcs are single digits but more important it dropped my rpms thru the quarter to where it made more power.
I have since upgraded to a rebuilt motor with aftermarket cam but want to ask you this? On the valve float issue, do you datalog? If you do did you notice this, because I think I am experiencing valve float on my current set up and I notice this: with my boost set to 19psi the data log looks pretty: it comes off the brake and rpms rise cleanly to the shift point then drop 900 rpm at the shift(powerglide) and then cleanly go up to the end of the quarter=146-to 147mph..
Now I only change the boost from 19 to 23psi and make a 1/4 pass. The RPM data log is flat as a pancake with a quick spike at the shift point then the rpms are flat and do not rise for the rest of the quarter=143-144mph Tune and timing are the same it just lays over.
If you dont mind, for that stock cam what did you set up/shim the installed height psi and what was it at max lift?
I have since upgraded to a rebuilt motor with aftermarket cam but want to ask you this? On the valve float issue, do you datalog? If you do did you notice this, because I think I am experiencing valve float on my current set up and I notice this: with my boost set to 19psi the data log looks pretty: it comes off the brake and rpms rise cleanly to the shift point then drop 900 rpm at the shift(powerglide) and then cleanly go up to the end of the quarter=146-to 147mph..
Now I only change the boost from 19 to 23psi and make a 1/4 pass. The RPM data log is flat as a pancake with a quick spike at the shift point then the rpms are flat and do not rise for the rest of the quarter=143-144mph Tune and timing are the same it just lays over.
If you dont mind, for that stock cam what did you set up/shim the installed height psi and what was it at max lift?
Last edited by turbo6man; 07-16-2014 at 02:25 PM. Reason: grammer
07-16-2014, 03:03 PM
#85
OP, your car is crazy man. I'm running a 4.8L in my truck with a S475/83 borg. I'm only running 12lbs right now since my fuel system is pegged but will be running 25psi through this engine at some point. I'm going to keep an eye on this thread. Get that ptc fixed and you'll be in the 5's ever pass.
07-18-2014, 09:27 PM
#87
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Wow that's moving. I had a 3.8 Buick with a 68mm turbo in my nova and with a dusty spec'ed 9.5 for 10.0 in the 135mph range.Worked perfect with the v6. Well I put a 6.0 in it and the convertor was way too loose and the data log showed it was running thru the whole quarter mile higher in rpms than where the bone stock motor made its best power and the slippage calcs were similar to yours. I sent it back to Dusty and he tightened it up for me and now the slippage calcs are single digits but more important it dropped my rpms thru the quarter to where it made more power.
I have since upgraded to a rebuilt motor with aftermarket cam but want to ask you this? On the valve float issue, do you datalog? If you do did you notice this, because I think I am experiencing valve float on my current set up and I notice this: with my boost set to 19psi the data log looks pretty: it comes off the brake and rpms rise cleanly to the shift point then drop 900 rpm at the shift(powerglide) and then cleanly go up to the end of the quarter=146-to 147mph..
Now I only change the boost from 19 to 23psi and make a 1/4 pass. The RPM data log is flat as a pancake with a quick spike at the shift point then the rpms are flat and do not rise for the rest of the quarter=143-144mph Tune and timing are the same it just lays over.
If you dont mind, for that stock cam what did you set up/shim the installed height psi and what was it at max lift?
I have since upgraded to a rebuilt motor with aftermarket cam but want to ask you this? On the valve float issue, do you datalog? If you do did you notice this, because I think I am experiencing valve float on my current set up and I notice this: with my boost set to 19psi the data log looks pretty: it comes off the brake and rpms rise cleanly to the shift point then drop 900 rpm at the shift(powerglide) and then cleanly go up to the end of the quarter=146-to 147mph..
Now I only change the boost from 19 to 23psi and make a 1/4 pass. The RPM data log is flat as a pancake with a quick spike at the shift point then the rpms are flat and do not rise for the rest of the quarter=143-144mph Tune and timing are the same it just lays over.
If you dont mind, for that stock cam what did you set up/shim the installed height psi and what was it at max lift?
07-29-2014, 11:12 AM
#88
Launching!
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What are you using for fuel management? Stock ecu? Microsquirt? Holley?? Nice power. Looking forward to seeing this thing with a new convertor and cam and springs
Kerry
Kerry
08-07-2015, 09:32 PM
#93
