Twin GT35R's vs twin TC76's info inside...Dr.Turbo?????
09-23-2008, 10:44 AM
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Twin GT35R's vs twin TC76's info inside...Dr.Turbo????? Same car,same trans, same gear, same size engine, DA was within 200ft, same boost, same AF ratio, same timing.
17psi GT35r's ran 146mph.......T3 turbos. 0.8x ar.
17psi TC76's ran 151.5 mph....T4 turbos. 0.8x ar.
TC76's did have 100 more lbs to pull due to more safety parts.
3850lbs vs 3970ish lbs.
Dr. Turbo....looking at the compressor maps, eff, mass airflow, etc...the TC76's should have gained 10mph or more.....obviously they will make much more power with more boost than the GT's....but, the GT35's are pretty impressive for a baby turbo.
Thoughts?
17psi GT35r's ran 146mph.......T3 turbos. 0.8x ar.
17psi TC76's ran 151.5 mph....T4 turbos. 0.8x ar.
TC76's did have 100 more lbs to pull due to more safety parts.
3850lbs vs 3970ish lbs.
Dr. Turbo....looking at the compressor maps, eff, mass airflow, etc...the TC76's should have gained 10mph or more.....obviously they will make much more power with more boost than the GT's....but, the GT35's are pretty impressive for a baby turbo.
Thoughts?
09-23-2008, 11:31 AM
#3
Same car,same trans, same gear, same size engine, DA was within 200ft, same boost, same AF ratio, same timing.
17psi GT35r's ran 146mph.......T3 turbos. 0.8x ar.
17psi TC76's ran 151.5 mph....T4 turbos. 0.8x ar.
TC76's did have 100 more lbs to pull due to more safety parts.
3850lbs vs 3970ish lbs.
Dr. Turbo....looking at the compressor maps, eff, mass airflow, etc...the TC76's should have gained 10mph or more.....obviously they will make much more power with more boost than the GT's....but, the GT35's are pretty impressive for a baby turbo.
Thoughts?
17psi GT35r's ran 146mph.......T3 turbos. 0.8x ar.
17psi TC76's ran 151.5 mph....T4 turbos. 0.8x ar.
TC76's did have 100 more lbs to pull due to more safety parts.
3850lbs vs 3970ish lbs.
Dr. Turbo....looking at the compressor maps, eff, mass airflow, etc...the TC76's should have gained 10mph or more.....obviously they will make much more power with more boost than the GT's....but, the GT35's are pretty impressive for a baby turbo.
Thoughts?
Nothing new....but look at it this way as well. You went 7mph faster with 100lbs more as well. Doing the math, that's ALOT more power at the same boost level. Not as close as you may think. Also factor in if you changed to a higher stall as well. 150+hp more already at same boost.....I'll take that any day and not worry about pushing water as well. Backpressure with the GT35R's will rise VERY fast.
09-23-2008, 12:04 PM
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The GT's sixty better due to all of the compromises to the car. (1.35 vs 1.55). The converter eff at top of each run was close in both cases. Chance knows turbo converters. If the car was built to race only, the TC's would sixty as good or better than the GT's...the GT's are a good "crutch" turbo for heavy weight, 3.00 gear, yada,yada,yada.....
09-23-2008, 12:07 PM
#5
The GT's sixty better due to all of the compromises to the car. (1.35 vs 1.55). The converter eff at top of each run was close in both cases. Chance knows turbo converters. If the car was built to race only, the TC's would sixty as good or better than the GT's...the GT's are a good "crutch" turbo for heavy weight, 3.00 gear, yada,yada,yada.....
09-23-2008, 12:12 PM
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Around 17lbs the GT35R's are getting towards the end of the maps. The TC76's have ALOT more to go. TC76's have already gone 170+mph. Also keep going on boost.....1200hp with GT35R's versus 1900+hp with TC76's....big difference.
Nothing new....but look at it this way as well. You went 7mph faster with 100lbs more as well. Doing the math, that's ALOT more power at the same boost level. Not as close as you may think. Also factor in if you changed to a higher stall as well. 150+hp more already at same boost.....I'll take that any day and not worry about pushing water as well. Backpressure with the GT35R's will rise VERY fast.
Nothing new....but look at it this way as well. You went 7mph faster with 100lbs more as well. Doing the math, that's ALOT more power at the same boost level. Not as close as you may think. Also factor in if you changed to a higher stall as well. 150+hp more already at same boost.....I'll take that any day and not worry about pushing water as well. Backpressure with the GT35R's will rise VERY fast.
It's obvious that I'm just greedy...I wanted 10mph at more weight at less boost
Is there a compressor flow map for the TC76's somewhere? The old T76 map is used a lot for GT76, TC76, etc,etc and obviously there is a big difference in covers....aren't the TC's a 60's series cover?
How does the Garrett 74mm map compare to a TC76 map.
TIA.
09-23-2008, 12:22 PM
#7
Very true that the GT's were getting close to the end. I didn't push them any harder since I was on the same head gaskets for 3 years and new they were near the end. Very true that the TC's will kill them after I turn the boost up.
It's obvious that I'm just greedy...I wanted 10mph at more weight at less boost
Is there a compressor flow map for the TC76's somewhere? The old T76 map is used a lot for GT76, TC76, etc,etc and obviously there is a big difference in covers....aren't the TC's a 60's series cover?
How does the Garrett 74mm map compare to a TC76 map.
TIA.
It's obvious that I'm just greedy...I wanted 10mph at more weight at less boost
Is there a compressor flow map for the TC76's somewhere? The old T76 map is used a lot for GT76, TC76, etc,etc and obviously there is a big difference in covers....aren't the TC's a 60's series cover?
How does the Garrett 74mm map compare to a TC76 map.
TIA.
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09-23-2008, 12:39 PM
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09-23-2008, 12:41 PM
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What's the actual ratings for the TC76, gt76 and the new TC78?
May have to try a set of 78's over the winter.
09-23-2008, 12:43 PM
#11
GT76 is the new budget Garrett based unit....its a T6 though. So not easy to compare to the other 2.
09-23-2008, 04:56 PM
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Around 17lbs the GT35R's are getting towards the end of the maps. The TC76's have ALOT more to go. TC76's have already gone 170+mph. Also keep going on boost.....1200hp with GT35R's versus 1900+hp with TC76's....big difference.
Nothing new....but look at it this way as well. You went 7mph faster with 100lbs more as well. Doing the math, that's ALOT more power at the same boost level. Not as close as you may think. Also factor in if you changed to a higher stall as well. 150+hp more already at same boost.....I'll take that any day and not worry about pushing water as well. Backpressure with the GT35R's will rise VERY fast.
Nothing new....but look at it this way as well. You went 7mph faster with 100lbs more as well. Doing the math, that's ALOT more power at the same boost level. Not as close as you may think. Also factor in if you changed to a higher stall as well. 150+hp more already at same boost.....I'll take that any day and not worry about pushing water as well. Backpressure with the GT35R's will rise VERY fast.
09-23-2008, 04:59 PM
#13
They are 3400 lbs limit. Also a member on this board went right at 170mph with a heavy car I believe. Members screen name is LastLS1
https://ls1tech.com/forums/member.php?u=7231
https://ls1tech.com/forums/member.php?u=7231
09-23-2008, 07:09 PM
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Turbonetics solved some of the mystery late today.
TC76 is only an 88Lb/Mn turbo....not the typical 96Lb/Mn T76
TC78 is a 92Lb/Mn turbo.
Garrett 74mm is 95Lb/Mn per the Garrett website.
Plenty of turbo to make killer power...just not as big as I originally calculated on a T76 compressor map.
TC76 is only an 88Lb/Mn turbo....not the typical 96Lb/Mn T76
TC78 is a 92Lb/Mn turbo.
Garrett 74mm is 95Lb/Mn per the Garrett website.
Plenty of turbo to make killer power...just not as big as I originally calculated on a T76 compressor map.
09-23-2008, 08:37 PM
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Turbonetics solved some of the mystery late today.
TC76 is only an 88Lb/Mn turbo....not the typical 96Lb/Mn T76
TC78 is a 92Lb/Mn turbo.
Garrett 74mm is 95Lb/Mn per the Garrett website.
Plenty of turbo to make killer power...just not as big as I originally calculated on a T76 compressor map.
TC76 is only an 88Lb/Mn turbo....not the typical 96Lb/Mn T76
TC78 is a 92Lb/Mn turbo.
Garrett 74mm is 95Lb/Mn per the Garrett website.
Plenty of turbo to make killer power...just not as big as I originally calculated on a T76 compressor map.
92= TC76
95= TC78
I worked with Tnetics to get the 78mm made in the CHRA. Dave engineered the cover to work with the 78mm, 5% total loss. Plenty to run 7's or blow the heads off.....or whichever comes first.
09-23-2008, 09:00 PM
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They also told me today that have T4 Turbine blankets (silver type) for $102 in stock that would last years. Is that a bunch of BS also?
09-23-2008, 09:04 PM
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Well which new guy did you talk to today....lol. Their are always new people there.....and their is NO map for that turbo. Just calculated flow....
I spoke to Dave about this almost 4 years ago....the money to map out a unit now is WAY to expensive. Around 1500-2K for 1 hour of testing. Minimum is around 4-8 hours to map complete for hot/cold sides. Never seen their blankets.....will have to look. If they have them, I'm sure we will be carrying them soon.
09-23-2008, 09:05 PM
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Peak total efficiencies are still the same....map just shifts a little to the left and total peak PR is just a touch down, but no LS1 runs at 50+psi, so that doesn't effect the performance on this application for PR's. Most LS based motors that I have ever dealt with or know of are mostly under a PR of 2.5-3.0.
