hypergear

The boost pressure at the compressor cover will be higher than at inlet manifold. lets say, trying to hold 20 psi flat at 7000 RPM. If your wastegate opens at 20 psi measured at the compressor cover, the engine may only be seeing 16 psi. Your base pressure reading at engine would be 20psi by 4K and 16psi by 7K while your MAP at compressor housing still reads 20psi at 7K. For this reason your ECU's MAP source is never on the compressor cover. This difference isn't a major concern if you're using an electronic boost controller (EBC).

I usually source pressure on inlet manifold after throttle body

Steam valve seals are usually responsible for cold start smoke, it goes away once engine warmed up. Disconnect it let engine breathers and let it breath freely, see if problem goes away after a short drive. Also check to make sure engine oil drain pipe is not blocked or kinked.

In many cases, aftermarket dump pipe inlet flanges don't properly align with the outlet of the turbine housing, as they were designed to fit within the constraints of a 3-inch pipe. When an oversized wastegate flapper valve is installed, it can interfere with the dump pipe flange. A bit of die-grinding usually resolves this issue. Additionally, the actuator must be preloaded, otherwise, the flapper valve may rattle. The stock wastegate also tends to open too early, so upgrading to a wastegate actuator with a stiffer spring can improve boost response.

Consider it as a G25-550 in a T3 .63 rear housing. So performance wise will be very similar.

Updating results following our SR20det project. Data collected form improves future turbocharger making and high flowing services. So far differences between G and GT series turbine wheels, we are in the process of making a new turbine, the aim is for better mid top range flow without gain too much lag. Result is back to back comparison of G25-660 and GTX2867 spec turbochargers on the same car, nothing changed apart from turbocharger. Both tuned to knock limit from pump 98 fuel (US Ron93). GTX2867 was about 400RPM more responsive making 255rwkws while G25-660 made 17 extra Kws with wider spread of torque after 4500RPM finishing off at 272rwkws.

Result of another R35GTR build. Similar specs as above except this is running our bigger size SS-2 profile option. Made similar power except this car runs on Pump 98 fuel. Build specs are: Nissan R35 GTR 2015 model stock engine and box. ETS street intercooler boost logi intercooler piping with tial bov, boost logi turbo inlet pipe ID 1050 injector DW 300C fuel pump Decatted oem down pipe and y pipe& HKS exaust 3inch intake pipe Upgraded actautors HyperGear SS-2 high flow option Final result is 639whp / 477wkws hubs, Ron 93 / P98 fuel at 20psi.

Sharing results from recent Liberty Walk R35 GTR, since they are still considered as somesort of a V36 Skyline. We do them turbos too. This are high flowed SS-1 models with ball bearing conversion done. Car have managed to pull 485awkws @ 20Psi so far pushing limitations of factory built engine. The build list for R35 GTR enthusiasts as follow : HyperGear high flowed stock turbos in SS1 (G25-660 specs) Custom titanium intake pipes. Vspec performance titanium front pipes. Vspec performance 4" titanium exhaust. Upgrade fuel pumps. 1200cc injectors. Ignition coilpacks Hks intake plenum. Hks intercooler piping. Greddy intercooler. Greddy bovs. Top-secret coolant reservoir. Emtron ecu. Straight E85. Built gear box.

The overboost could be more of a cause. Broken turbines usually ends up in the cat, time to engine rebuild. Blown stock turbos can be high flowed with bigger and modern wheels for greater power goals.

Not yet. The current 45mm Gen 4 gate is already a tight fit. I don't think the EWG 40mm is going to squeeze in that spacing.

I’m doing some side developments on SR20det S13 engines, its one my hobby cars used it to compare flow capacity of some smaller size wheels. SR20det is one of another JDM legendary engines I'm sure there are plenty of SR enthusiasts on this forum, I will share results some common turbo configurations here. a quick run down of what the car is: Wide body 180sx Type X with black top engine (blue). It has: Stock bottom end Haltech 1500 ECU 5-0 motorsports trigger kit Kelford SR20DET Beehive Spring with Titanium Retainers Kelford Cams SR20DET S13 188-B 268/272 Cams G25-660 Turbocharger in T2 .64 rear housing internally gated ARP Head studs MLS head gasket 1000CC ID injectors Walbro 450L Fuel pump Front mount cooler kit JJR’s 3 inches turbo back exhaust (its too short for the 180sx it had to be extended) Pump 98 fuel Hub Dyno tune So far made 270rwkws at 22psi full boost by 4500RPM. Engine is very knock limited hence a pretty bad looking top end. From previous experiences it seems like SR20dets are happier with bigger size turbine, some thing like a GT30 would make way better top end, but on same time response is lost. It won't be a problem with S15 VCT engines. I'll be testing alternative turbine housing, turbine wheel and possibly dump pipe options for extra flow to resolve the problem and of course E85 would resolve all the issues.

Updating results from our ATR43SS-1 turbo in T3 .63, OEM bolt dump pattern. Not a big number but pretty sweet for a stock Rb20det. Car's managed to pull 220rwkws at 20psi, perfect boost control internally gated with EBC and excellent mid top end power band as they usually skydive after 5.5K. Usual bolt on supporting mods and inlet plenum and factory location exhaust manifold. Pump 98 fuel was used (Ron 93).

Might also needs a stronger actuator with the right preloading. With older 2019 built bush G3 units, BB upgrade or 21U housing down size makes a pretty decent gain in response as well.

Car would be very knock limited on pump 98 fuel, this is also why lots of old school turbos has such a massive turbine end to drive a small compressor. Overall a decent result for pump fuel,

Greater amount of energy is required to turn larger wheels up to speed, there for laggier. However bigger wheels are capable of flowing greater amount of air through both housings, let the engine burn more fuel and makes more power that way.