DOC Race going big with Precision PTE6870 turbocharger to replace Comp 6465BB on their N54 shop car

[DOCRace]

Well this is as big as we can go with the current manifold design and location. Took the tapped out Comp 6465BB and installed the PTE6870 which is their newest bad boy turbo packed in a small frame turbo. I got the 1.15A/R which I planned on using with a built motor. Since that might not all be together for a while I was just itching to install it so I did yesterday.

Note to anyone wanting to run this exact turbo (1.15A/R) with our manifold: It fits but you might have to trim the engine cover, bend the heat shield, remove some of the factory chassis glue. The housing is huge compared to the standard **66 1.00A/R. I made it all fit without cutting the engine cover and also installed the new DOC Race lava turbo blanket.

First off I just want to say there have been a lot of horror stories about Comp turbos. I may have just gotten a lucky one but this turbo has been super reliable. The only thing that did annoy me was there was oil coming out of the compressor housing and made it look bad when I showed people the car. Other than that it made 750whp on race gas. I put a good 10K miles, some race but mostly pump and never had an issue with it other than the oil in the compressor.

First impressions after install: At first start up it was a lot louder so I can definitely tell the exhaust is now really moving. Took it out for a spin to burn off all the oil left from handling the exhaust parts and yes, it has quite a bit more lag which is what I was expecting. Got it back to the shop, checked everything again. Also noticed that once I turned the engine off the turbo spun for much longer than the Comp. I would say it spun for almost a good minute.

Took it out for another spin. This time took it up higher in rpm and boost logging everything this time. Again, this thing sounds like a different car. Much louder and again more lag. Was able to log a couple runs. A/F was spot on still so I feel safe enough to at least drive around town low boost. 4th gear I was about to reach 20psi at 3850rpm. I wouldn't say that's too bad. With the Comp 6465 I was able to get 20psi by 3300rpm.

So forget about all this low boost talk, what does this really mean? I talked to Andy at AD-Engineering and he's going to try to squeeze me in for a tune also adding a couple other things that I will mention later AD-Engineering and Horsepower Barn have a few cars going to Shift Sector 1/2mi race in Oregon in Spet. 10-11 which I will be attending as well so we will be seeing some fast BMW's out there. I will keep everyone updated on the tune.

[bigdnno98]

20psi by 3850 is pretty good for that turbo. I don't think Payam could get his to spool that fast.

[Stucks]

wow, very impressive! looking forward to more updates as always.

[Payam@BMS]

20psi by 3850 is pretty good for that turbo. I don't think Payam could get his to spool that fast.

Actually I had it about 3500-3600 with 4th gear pull. However conditons and gear will make the most difference.

The 1.15AR is huge though, I didnt run out of exhaust on the .84AR with 38 psi on a log. I dont really see any reason in going that big unless you plan to run 50+ psi IMHO.

[Sticky]

Edited and promoted to front page.

[bigdnno98]

Actually I had it about 3500-3600 with 4th gear pull. However conditons and gear will make the most difference.

The 1.15AR is huge though, I didnt run out of exhaust on the .84AR with 38 psi on a log. I dont really see any reason in going that big unless you plan to run 50+ psi IMHO.

If you got it to spool that quickly, why were you so unhappy with it?

[omarmarji]

i want that intake manifold so bad

[DOCRace]

Actually I had it about 3500-3600 with 4th gear pull. However conditons and gear will make the most difference.

The 1.15AR is huge though, I didnt run out of exhaust on the .84AR with 38 psi on a log. I dont really see any reason in going that big unless you plan to run 50+ psi IMHO.

I got the 1.15A/R because I planned on putting it on a built motor. I will admit the 1.15 is an overkill on a stock motor.

[bme30]

Were did you get your turbo guard??

[andy_divers]

Battle of the 6870's at Oregon shift sector

[Abacus38]

Is there space for the 72mm?

[jt0407]

Is there space for the 72mm?

Can always make room... But, we need more RPM, first.

[DOCRace]

Is there space for the 72mm?

Like jt0407 said. There is always room. But lets see someone max out a 6870 first.