Went from pt7675...to on3 7876
Thread Starter
TECH Junkie
Joined: Jul 2015
Posts: 3,012
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The pt76 is a bad **** for its size no doubt about that at all. There are mod motor cars running bottom 8s in the 1/4 with it. If you honestly expected a China turbo to be equal or better for a fraction of the cost I'm not sure what to tell you. I have the old 76gts which has been going strong for a long time but I read at one point precision stopped using Garret parts and started having issues.
I'm not sure you read my full post. I know there have been a ton of precision turbo problems lately. As far as I know Garret turbos stop supplying them with parts sometime in the past years and they started having a lot of issues. Would I buy a brand new precision turbo? No, but they make amazing power and that 76mm wheel flows 120 lbs/min. Their turbos have a ton of tech and making amazing power but I still wouldn't buy a new one. They are top performance there is no doubt about that but I never stated they are top quality. I should have rephrased it to read that if you believe a china turbo will make the same power as a precision I don't know what to tell you. In your situation I would have done the same thing with the on3 or turbonetics 76/75 but I would know that the power will be down. Their H cover simply flows more than the others small compressor covers.
My on3 is quiet also,I doubt your making more power with it unless you up'd the boost.I feel the precision wouldve been a slightly more efficient turbo and spool up harder.The on3 are decent budget turbos..I dont expect the world from it.
Thread Starter
TECH Junkie
Joined: Jul 2015
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The precision definitely made good power, and really....I liked it. I guess what really made me go bad is, not only did the turbo have a short life. But the fact that they wouldn't even give me a ballpark figure of what it would be to rebuild the thing. It wouldn't surprise me in the least, if I sent it in......then they call me with some insanely inflated bill.....telling me that the whole thing was junk and they had to replace everything.
Ya I also called precision and they would not give any estimate. Kinda irritating but also understandable working in a diesel tech shop. Estimates can be very far off. But something as small as a turbo you would think an estimate would be easy, o well. I'm doing the opposite swap, going from an on3 to the 76gts I just had rebuilt from precision. Im hoping to make a lil more power cause room on an f body is tight ha.
Thread Starter
TECH Junkie
Joined: Jul 2015
Posts: 3,012
Likes: 48
Ya I also called precision and they would not give any estimate. Kinda irritating but also understandable working in a diesel tech shop. Estimates can be very far off. But something as small as a turbo you would think an estimate would be easy, o well. I'm doing the opposite swap, going from an on3 to the 76gts I just had rebuilt from precision. Im hoping to make a lil more power cause room on an f body is tight ha.
Thread Starter
TECH Junkie
Joined: Jul 2015
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Wow. $600 to rebuild.....ridiculous. I'm fully aware that you've got to pat to play.....and they have to make money as a business. But still, that's ridiculous. Thanks for sharing that info though.
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Ya I was lil surprised as well but o well. It is what it is. I'm sure it's a lil inflated just like Deere but I didn't wanna tackle it myself. Hopefully I can it swapped on with a different converter before winter and see what name brand vs China looks like
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TECH Junkie
Joined: Jul 2015
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Since it looks like the track is going to be rained out this weekend, I may put the car back on the rollers to see what the difference between the two is. I already know what the car made with the precision. Will even use the same dyno.
I'm very interested to hear the results. Good or bad I think a lot of people will be happy to have some nice concrete numbers to compare. If it's a -50whp difference that's still a win for the on3 in my book.
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TECH Junkie
Joined: Jul 2015
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Got the coupler issue taken care of yesterday. Got off work this morning, and was finally able to flog the car really good due to no traffic. If the car is down on power, I definitely cannot feel it. One thing I did notice is, I don't have to turn the controller up as high to get the same boost (not really important though). Ran the turbo at 19.5 psi....and it felt GREAT. And I agree, should I come up 50 rwhp short...I'm cool with it. That will be easily fixed with a laptop.
I never dynoed it, just using time slip and scale information to get a general idea. Car ran 9.5-9.8 @ 140-145, started out crossing the stripe at 4220lbs and eventually got the car weight down to ~4000lbs. Started out about 20 PSI and worked it up to 24-26lbs.
Got the coupler issue taken care of yesterday. Got off work this morning, and was finally able to flog the car really good due to no traffic. If the car is down on power, I definitely cannot feel it. One thing I did notice is, I don't have to turn the controller up as high to get the same boost (not really important though). Ran the turbo at 19.5 psi....and it felt GREAT. And I agree, should I come up 50 rwhp short...I'm cool with it. That will be easily fixed with a laptop.
Thread Starter
TECH Junkie
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Well, I made the comment in someone else's thread that this on3 didn't light off as quickly as the precision. Im thinking my perception was thrown off, due to the turbo being so quiet. This morning when I made a couple of hits, it seemed to be REALLY close to the precision....if not a little better. I'm trying to be as objective as possible, as I know that many times when you get something new.....the butt dyno can be terribly generous.
The On3 7875 was done at 700 rwhp through a TH400 and then he put in the PT7675 and made another 100 rwhp at the same boost level which was around 18-19 psi I believe. It was a while ago but I remember it being pretty definitive and not really a surprise that a chinese cast turbo like the On3 would be left behind.
Well, I made the comment in someone else's thread that this on3 didn't light off as quickly as the precision. Im thinking my perception was thrown off, due to the turbo being so quiet. This morning when I made a couple of hits, it seemed to be REALLY close to the precision....if not a little better. I'm trying to be as objective as possible, as I know that many times when you get something new.....the butt dyno can be terribly generous.
The On3 7875 was done at 700 rwhp through a TH400 and then he put in the PT7675 and made another 100 rwhp at the same boost level which was around 18-19 psi I believe. It was a while ago but I remember it being pretty definitive and not really a surprise that a chinese cast turbo like the On3 would be left behind.
What engine is the 7675 on to make 800whp through an auto at 18-19PSI? That's really good, I've seen others have to run it up to 24-26+ PSI to make close to that number.
Did you use a cast PT7675 or did you swap it for a PT7675CEA? Seems odd to be done so early when others have made more power with 7875, granted the TH400 sucks up a lot. A manual car would probably see 800whp with the 7875 which is why we've seen some 750whp dynos with it at relatively low boost. Did you crank up the boost on the 7875 and it just wasn't making any more power? I ran the On3 88/83 up to 26psi were it just wouldn't make anymore.
What engine is the 7675 on to make 800whp through an auto at 18-19PSI? That's really good, I've seen others have to run it up to 24-26+ PSI to make close to that number.
What engine is the 7675 on to make 800whp through an auto at 18-19PSI? That's really good, I've seen others have to run it up to 24-26+ PSI to make close to that number.