760hp/745tq Stock Bottom LS1 (TC78 to PT7675)
#1
760hp/745tq Stock Bottom LS1 (TC78 to PT7675)
Put this up in the dyno section too, figured you guys might enjoy it more.
Swapped my turbo out from a TC78 to a Precision 7675 GTS-H. The bigger turbine let the car hold boost better and it made 690 right off the street.. no changes whatsoever. threw another degree in it through the entire range and fattened it up to 11.0AFR throughout (was 11.4-5 through the first pull). Tuner said my 80lbs were maxed on this pull but it was pretty cool to see.
Timing at peak torque is 14deg, at peak hp its 19-20deg.
Boost was at 16psi and fell to 15psi by the end of the pull.
IATs went from 67* to 98* by the end of the pull (4" thick ebay intercooler)
Left the dyno at 12lbs so its back down to 680-690. I still may bring it down some more cus the rods are going to be extremely angry with me, all depends how i gear the car.
Side note: when it made 630 last year, the car had stock heads(853s), stock head gaskets and stock head bolts.
Link to last years results: https://ls1tech.com/forums/dynamomet...hp-inside.html
This year: stock untouched 317s, ls9 gaskets, and ARP head studs. NO other changes, at all (besides turbo).
So realistically, i picked up 60rwhp by switching to the PT7675 and putting on the 317s, not bad.
Ill get a video this weekend when i go back for the dyno day, we had to sit on the rear to keep if from spinning so i couldnt get one.
Swapped my turbo out from a TC78 to a Precision 7675 GTS-H. The bigger turbine let the car hold boost better and it made 690 right off the street.. no changes whatsoever. threw another degree in it through the entire range and fattened it up to 11.0AFR throughout (was 11.4-5 through the first pull). Tuner said my 80lbs were maxed on this pull but it was pretty cool to see.
Timing at peak torque is 14deg, at peak hp its 19-20deg.
Boost was at 16psi and fell to 15psi by the end of the pull.
IATs went from 67* to 98* by the end of the pull (4" thick ebay intercooler)
Left the dyno at 12lbs so its back down to 680-690. I still may bring it down some more cus the rods are going to be extremely angry with me, all depends how i gear the car.
Side note: when it made 630 last year, the car had stock heads(853s), stock head gaskets and stock head bolts.
Link to last years results: https://ls1tech.com/forums/dynamomet...hp-inside.html
This year: stock untouched 317s, ls9 gaskets, and ARP head studs. NO other changes, at all (besides turbo).
So realistically, i picked up 60rwhp by switching to the PT7675 and putting on the 317s, not bad.
Ill get a video this weekend when i go back for the dyno day, we had to sit on the rear to keep if from spinning so i couldnt get one.
Last edited by Ryans99ls1; 04-30-2013 at 12:01 AM.
#5
With the TC78, no matter what i did it would spike to where i wanted it (12lbs) and then fall back to wastgate(9.5lbs) by redline. I put the the PT76 on, didnt touch the **** from last year and it held it to 11lbs. The backpressure was the biggest issue. Ill get an electronic controller on it this year.
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#8
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Thanks! But yeah Ive been meaning to buy an eboost street but have literally not had the time to buy/install it. Ive got a 2step/wot box i need to install as well.. along with a clutch and new rear gears lol
With the TC78, no matter what i did it would spike to where i wanted it (12lbs) and then fall back to wastgate(9.5lbs) by redline. I put the the PT76 on, didnt touch the **** from last year and it held it to 11lbs. The backpressure was the biggest issue. Ill get an electronic controller on it this year.
With the TC78, no matter what i did it would spike to where i wanted it (12lbs) and then fall back to wastgate(9.5lbs) by redline. I put the the PT76 on, didnt touch the **** from last year and it held it to 11lbs. The backpressure was the biggest issue. Ill get an electronic controller on it this year.
#9
No reason it shouldnt! things really started taking off past 12lbs.. it was wild. Amazing what a turbo in its efficiency range can do huh? haha
Oh that it is. The m/t's hold perfect in 3rd and 4th. 2nd too if let it spin a couple times. glad i could serve as some motivation!
i like the big digital readout too. much easier to see if things are where you want them to be.
Yea for the money I love mine. I had the same issue with my manual BC dropping off up top. I wired up the eboost street and never touched the rpm correction and it hit my target boost perfect and held it perfectly all the way to redline. At half the price of the eboost 2 its often overlooked for some reason.
#10
TECH Addict
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Yea for the money I love mine. I had the same issue with my manual BC dropping off up top. I wired up the eboost street and never touched the rpm correction and it hit my target boost perfect and held it perfectly all the way to redline. At half the price of the eboost 2 its often overlooked for some reason.
OP you sould do video soon of your car, I need motivation
#11
heres vid from when it was around 600 with the TC78. i need to borrow my buddies go pro, gimme a week and i should have a few. Graduation and what not is taking over this week for me.
#14
TECH Senior Member
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I put mine in my glove box because there really isnt a need to have it in sight when you have a boost gauge already. The 2 can do boost by gear and I think more then 2 boost settings. Other then that they use the same solenoid. I dont need boost by gear so that is a useless feature IMO. I also only have a high boost tune and low boost tune.
#15
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I put mine in my glove box because there really isnt a need to have it in sight when you have a boost gauge already. The 2 can do boost by gear and I think more then 2 boost settings. Other then that they use the same solenoid. I dont need boost by gear so that is a useless feature IMO. I also only have a high boost tune and low boost tune.
#16
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I didnt plan on going overkill parts on this 347 ci engine when everyone is doing 6.0's and lsx engines... but I wanted something I could beat on for a good year or so and not have it break for any reason.. then I can sell it to help fund my future build, plus I can reuse half the stuff on my next build..
dang 138? if you can hit that good for you bro...
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Very nice numbers! Maxing out the 80 lbs, wow! What was your duty cycle at that power level? What fuel system do you have?
Does anybody know what power level the pt7675 can handle comfortably without maxing it out? 800, 850rwhp?
Does anybody know what power level the pt7675 can handle comfortably without maxing it out? 800, 850rwhp?