TP38 turbo on 5.3L, Turbo people I would appreciate your opinion
01-26-2009, 10:09 PM
#11
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I attached a compressor map of a Garrett T4 series T04B 60-1. I also attached a dyno graph posted by a guy on here with screename Bill Reid. His setup was a RCSB 5.3L stock cam with comp 918 springs and pushrods. He has a 60-1, and this dyno was done at 9 psi. I'm not sure, but I think it was through a 4L80 trans.
I have been reading about compressor maps and how to read them. From a chart I found on forcedinductions.com it says that a 346cid LS1 @ 9psi has a pressure ratio of 1.61 and from 3400 RPM to 5500 RPM covers a range of 32 to 51 on the lb/min scale. At 12psi PR is 1.82 and covers a range of 36 to 58 from 3400-5500 RPM on the lb/min scale.
So you basically plot a horizontal line across the map with those coordinates and see if you stay within the surge and choke lines while staying in the efficiency range of the turbo.
I can see how the 60-1 is a great choice, It seems to reach the choke line right at the RPM limit of the engine, which based on what the dyno graph shows, is about 5500 RPM.
But the TP38 seems to be doing the same thing, maybe falling off at 5200-5300 instead of 5500.
Look at 3000-4000 RPM range at 12psi on the TP38, it is plowing right through the highest efficiency point on the entire map, that seems like a tire shredding place to be...
The thing is, this turbo has a T4 exhaust flange just like the 60-1, T66, T76, all the good ones. If I put this one on and it doesn't do good, it really won't take much to do something different turbo wise.
All of your comments have been appreciated.
I have been reading about compressor maps and how to read them. From a chart I found on forcedinductions.com it says that a 346cid LS1 @ 9psi has a pressure ratio of 1.61 and from 3400 RPM to 5500 RPM covers a range of 32 to 51 on the lb/min scale. At 12psi PR is 1.82 and covers a range of 36 to 58 from 3400-5500 RPM on the lb/min scale.
So you basically plot a horizontal line across the map with those coordinates and see if you stay within the surge and choke lines while staying in the efficiency range of the turbo.
I can see how the 60-1 is a great choice, It seems to reach the choke line right at the RPM limit of the engine, which based on what the dyno graph shows, is about 5500 RPM.
But the TP38 seems to be doing the same thing, maybe falling off at 5200-5300 instead of 5500.
Look at 3000-4000 RPM range at 12psi on the TP38, it is plowing right through the highest efficiency point on the entire map, that seems like a tire shredding place to be...
The thing is, this turbo has a T4 exhaust flange just like the 60-1, T66, T76, all the good ones. If I put this one on and it doesn't do good, it really won't take much to do something different turbo wise.
All of your comments have been appreciated.
01-26-2009, 10:16 PM
#13
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The pressure ratio is what pressure you are going to run.. The ratio is based off sea level atmospheric pressure of 14.7 SO If you "plan" on running 9 psi of boost and live at 3000-4000 feet you would have a higher pressure ratio of someone running 9 psi at sea level....
01-26-2009, 10:21 PM
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For example....
Sea level dude buys a cheap E-bay air to air cooler that has a 3 psi pressure drop at 10ish psi, He wants 10 psi of boost in the manifold, SO he would need 13+14.7=27.7 of Apsolute pressure..
Divide that by 14.7 you get a 1.88 pressure ratio....
Sea level dude buys a cheap E-bay air to air cooler that has a 3 psi pressure drop at 10ish psi, He wants 10 psi of boost in the manifold, SO he would need 13+14.7=27.7 of Apsolute pressure..
Divide that by 14.7 you get a 1.88 pressure ratio....
01-26-2009, 10:57 PM
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Is this going to be a rear mount or front? I had a 60-1 on my STS and 5.3L with a .84 housing and it spooled very quick. I think any bigger on the exhaust housing and it wouldn't have spooled very well. I do disagree a little with the comment on the valve springs. I had noticable valve float with the turbo, stock springs and stock cam. I through in a set ls6 valve springs and it cured the valve float in the higher rpms. Also, I have the 60-1 sitting around from the STS kit that I would let go really cheap.
01-27-2009, 08:21 AM
#17
The compressor maps maybe simular what about your turbine side. The turbo you listed has a much larger a/r then what is normally ran with good power, low spool rates. The 62 we use has an .81 a/r.
This does not mean it will not work just alot different. If the turbo is cheap enough I would recommend trying it. Keep in mind if the spool is not what you want, start dropping the exhaust a/r.
Take lots of pics, and let us know how it turns out.
This does not mean it will not work just alot different. If the turbo is cheap enough I would recommend trying it. Keep in mind if the spool is not what you want, start dropping the exhaust a/r.
Take lots of pics, and let us know how it turns out.
