Quote:
Originally Posted by thedugan
Mark, a lot of people with supercharged motors run hydro boost setups or now the huge electric masters. You look to be using the DSE booster and master setup. How do you make that work with all of the track driving you do and having vacuum for the brakes? The reason I ask is I don't want to use a hydro boost or an electric master on my future procharger setup. Want to stick with my DSE setup.
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While I'm not Mark, GM does use an auxiliary electric vacuum pump on the ATS-V to supplement vacuum for the brake booster when the engine is under boost... it works great. There's a vacuum sensor right at the inlet of the brake booster and the ECM will cycle the auxiliary electric pump as needed if the brake booster vacuum drops while the engine is under boost, something which can happen if you're a heavy left foot braker.
The factory electric vacuum pump on the ATS-V is made by Hella, and they're obviously OEM quality and reliable. Hella makes several vacuum pumps with different volumes and duty cycles; many hybrid cars use them as well as the sole source of brake booster vacuum when the car is running in straight EV mode.
The ones I've had very good luck with is Hella # 8TG-012-377-701, it's one of the heavier duty, higher volume, higher duty cycle pumps for hybrids and the like. The one GM used on the ATS-V is a much lower volume, lower duty cycle unit only meant to supplant engine vacuum very occasionally, and the OEM ECM has some logic to limit the vacuum pump duty cycle to prevent overheating it. I've used the larger, higher duty cycle 8TG-012-377-701 on both turbo cars and cars with big cams and poor idle vacuum and also on a couple of rock crawlers where guys didn't want to use a hydroboost but also where losing vacuum to their power brakes would be a real problem if the engine died while all crossed up on some rocks. They pull vacuum very quickly, are quiet while doing so, and are very reliable.