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Stock 4.8 802RWHP but valve float now

 
Old 05-13-2014, 09:11 AM
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Originally Posted by ls1CANTU View Post
I did a junkyard 5.3 with some 243's on my friends Silverado and went with our boostaholic 2 cam and pulled 823 RWHP. His truck ran 10.50's at 134 MPH full weigh plus added weight of roll cage

What year 5.3?
Any cam specs?
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Old 07-16-2014, 12:56 PM
  #82  
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Wow great thread!
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Old 07-16-2014, 02:23 PM
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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?

Last edited by turbo6man; 07-16-2014 at 02:25 PM. Reason: grammer
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Old 07-16-2014, 02:34 PM
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what exaust wheel are you running on that 6.0 you might be getting to a point where the back pressure is to high . is the afr still good ? not blowing out the spark?just throwing it out there. but it does sound like valve float.
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Old 07-16-2014, 03:03 PM
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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.
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Old 07-17-2014, 07:00 AM
  #86  
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What are you running for fuel? Is that e85? Any pics of the engine bay ? Intercooler ?? Water meth??

Nice work. She haulin the mail
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Old 07-18-2014, 09:27 PM
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Originally Posted by turbo6man View Post
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?
Originally Posted by yenkomike View Post
what exaust wheel are you running on that 6.0 you might be getting to a point where the back pressure is to high . is the afr still good ? not blowing out the spark?just throwing it out there. but it does sound like valve float.
I hope Im not clogging up your thead I was just wondering if you had experienced the same on your datalogs? To answer yenkomike I had a PT88 t4 .96A/R and I thought it was back pressure so I installed a t6 flange with a s484 96mm exh with a t6 1.32A/R. It ran the same in the 1/4 with both turbos. I kind of suspected it was valve float but I thought the back pressure of the t4 was making it worse. I have a totally wrong cam in it(way to much duration and overlap) and after buying the turbo and a new cam from one of the venders on here(wanted to try the turbo before I changed the cam) I realized from the vendor my spring seat pressure is waay low. So I will change the cam now and up the spring pressure as per new cam spec'ing. AFR on the tune was good and I put new plugs in it and gapped them anywhere from .019 to .023
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Old 07-29-2014, 11:12 AM
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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
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Old 08-07-2015, 03:49 PM
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Engine still stock?

how much miles you already run with this setup?
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Old 08-07-2015, 09:10 PM
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Old 08-07-2015, 09:11 PM
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That a 5.3 317 heads and twin on3 76mm 26lbs and a cam I did.
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Old 08-07-2015, 09:29 PM
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Originally Posted by ttls1coupe View Post
That a 5.3 317 heads and twin on3 76mm 26lbs and a cam I did.
Awesome numbers man
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Old 08-07-2015, 09:32 PM
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Originally Posted by Nismo Kid View Post
Awesome numbers man
Thanks I'm getting my new turbos this week got Percision 62/62 with .58 ar's. Think I'll make same power but at 20lbs just cause there way better turbos should know this week
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Old 08-07-2015, 10:05 PM
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Originally Posted by ttls1coupe View Post
Thanks I'm getting my new turbos this week got Percision 62/62 with .58 ar's. Think I'll make same power but at 20lbs just cause there way better turbos should know this week
Keep us posted man. The 62/62 is a great unit.
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Old 08-08-2015, 10:06 AM
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What were the final numbers on that Mustang? I couldnt read it.
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Old 08-08-2015, 11:43 AM
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Originally Posted by SSZ View Post
What were the final numbers on that Mustang? I couldnt read it.
946hp
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Old 08-08-2015, 09:44 PM
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i guess my eyes arent playing tricks!!!!
Real nice numbers.
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Old 05-07-2017, 08:05 AM
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Originally Posted by dmaxvaz View Post
a member here "stock48" used a isky triple 12 cam with great success.
I'm trying to get ahold of stock48 new to this site I've tried searching for him
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Old 05-08-2017, 12:32 PM
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Love the car, building an 87 Turbo T myself. What radiator and fan setup did you use?
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