CGS Mike thanks for the dyno’s.
Looks like comparing the 2 on high boost e70 the SC has the turbo beat from 2.5k to 3k by only 10hp, after that the tides turn heavily in the turbo’s favor.

Although I would not be disipoited in ether one.

I have a turbo on my car now, so don't take this the wrong way... but in my opinion this post doesn't really support your position very well...

1) your "more reliable" statement is factually incorrect for a couple reasons. The turbo is not the 1 moving part. There's also the wastegate and the bov, both of which have diaphragms inside them that can fail, flanges that can leak, and vacuum lines going to them that can fail. Also the couplers for all the pressurized tubing love to "move", i.e. blow off and/or burst, and thus fail. There's also the entire cooling system for the turbo which loves to leak... oil/water. So let's not oversimplify.

2) also, your lag example - that's.... a lot of lag in comparison. The Harrop with a mid-level boost pulley makes 12-13 psi at 2k rpm instantaneously (within milliseconds). It's so un-laggy that it's dangerous for the motor.

Of course, with a correctly sized turbo, with a modern architecture like a GTX v2 or EFR, lag is dramatically reduced - again reaching the point where torque can be made at a low enough rpm to be dangerous for the motor. So I'm not arguing merits of one vs the other.

Having just swapped from a Harrop SC to a PRL turbo kit with a GTX2867r, I'm quite happy with the transient response of the turbo setup. In fact, at times it's too instantaneously torquey at mid-high rpm.

I have been driving with JRSC for more than 12K miles all year, rain, snow, shine. Simple, efficient, reliable, super smooth CARB certified tune ... I would buy again without any hesitation.

Nobody sells more turbo kits than SBD in North America.

About 500/year in the USA alone.

It's a fantastic match with the Auto Trans!

Not the wrong way at all!

Yes the wastegae moves but not much, so your chance for wear failure is small.

I read a lot of threads on the SC, that was the initial direction I was going. Somewhere in one of them a member compared all the supercharger posts and problems people were having. The most reliable SC was the Jackson. This system shares the same design in intake piping, and a BOV/Recirculation valve. Another item that swayed my decision is when the SC itself fails everyone was talking st over $2k to replace out of warranty. You can get a realy good Turbo for that price!

The chance of hose failure is almost nothing when properly selected, installed and secured. 99%+ of hose failures are caused by improper routing/securing,maintaining(yes rubber hoses have to be replaced at 7 years, Silicone probably 12) or torque of the clamp.

A properly installed and maintained turbo or supercharger will be reliable. The simplicity of the turbo just leans itself to win out by a little.

Not sure I beleive 12-13psi at 2k. Not saying it is not true but would have to see that one to beleive.

I know the HKS V2 units had failures of a particular internal component. However I have enjoyed my V3 derived replacement unit extensively this year and will take it on the track 2nd time this Mon. It is small and adds little weight and likely has minimal effect on COG. It is unfortunate that several weak units were sold previously as this is a great package otherwise. I suspect that few people that read this forum will jump on. For units produced in 2017 there appears to be no reported issues unlike those from 2015. Without failures, the HKS unit is just the right package for me without clutch or other issues at 276whp/209tq.

Some turbos create massive under hood heat. Granted heat blanket and wrap should be applied. However I think heat coating/wrapping the exhaust manifold can potentially result in eventual failures or cracking due to the extreme red hot heat these pipes must then withstand then cool down over and over.

I checked all options. There were no turbo options simpler than JRSC.

I love turbos and would probably prefer the drama of one to a supercharger, but my experience is biased because the Harrop SC will be my first SC when I install it. I went SC for emissions and reliability.

Reliability wise, turbos are good but I wouldn’t call them simpler or more reliable. Like johan and others pointed out, failures are probably more common. Because they tend to boost higher, the couplers fail more. Because they require external oiling/cooling, leaks and failures are more common. Oil change intervals may get shortened more with the extra oil wear from oil cooled turbos.

Then there are the really bad things like manifolds cracking leading to leaks all the way to engine failures. Wastegates can be inadequate leading to boost creap. Wastegate springs can stick or fail leading to huge boost spikes and ultimately engine failure. The heat can be hard to manage; Ive seen it melt catalytic converters fast when the tune was off. I’m not a tuner, but I bet the turbo is harder to tune than a SC.

Yes I was contemplating the HKS kit. I looks great and the power output was in the ballpark of what I was looking for. I know they improved the V3 but was scared of by the amount of issues reported on the earlier kits. Also about some comments of the company standing behind the product. Yes most of those were earlier kits but still made me wonder.

That is a good looking SC!

Now we are comparing apples to oranges. When you state boost higer, engine failures. These are from poor tuning or improper use. Exhaust crack, who cares I drive home with it and weld it back up with the stress relieved. Boost creep I know about it on my MAP gauge and do not floor it. Poor tune, once again it does not matter SC or Turbo this will cause problems. Once again ease of install is not the same as simplicity of design and operation.

Talk about a :threadjacked:

The best SC or Turbo for a AT car is the one that will just get to the HP you want. Install it correct, Have it tuned by Delicious!(or any good tuner). Then the important part is to Maintain it! That last part get forgotten a lot and then the kit or brand gets blamed.

Lets play devil's advocate here, and also delve a bit more into why I specifically chose the GReddy turbo kit for my car.

1. It is physically impossible for me to overboost. The turbo is sized properly, and I can't blow an engine from a wastegate suddenly getting stuck. I have no blowoff valve that can fail; the Mitsubishi 18G used in the kit is strong enough to not need one. To this day, I have never, ever, seen a failed turbo from the T518Z kit, and there are quite a few out there, many of them driven as hard as mine.

2. With an extended pull, I can have full boost at 2300 rpm. My transient response is good enough that I have boost on throttle blips, and is both heard when I heel-toe downshift, and is visible on datalogs.

Bonus: because I don't have a BOV, I don't release boost between shifts on pulls. I don't have to respool cuz I stay spooled.

Before people say the turbo is too small, I make 350whp/450crank hp on 10.5 psi boost, with a stock front pipe, and stock catback. Obviously, there's more power and response left untapped by my setup, but I like having a stealthy silent setup that doesn't smell.

Dude. No offence, but go read... there are already a ton of threads on pretty much all the options for this car.

Personally went the SC route and I’m very happy (as are a ton of TC owners etc).
I did it for the simpler install, easier maintenance, and immediate throttle response. Gives me everything I needed.

Best advice I can give you is try and get a drive in different cars with some of the options you want.
For e.g. I went in 2 different rotrex cars - great kits, but lacked lower down oomph where I do 99.99% of driving in my street driven car.
Had I not done this I would’ve ordered one. Ended up going for the Sprintex SPS kit. I might lose a few hp up top, but I’ve got good low and mid range & zero lag.

FYI while we are here and CGS mike is posting about never seeing a turbo failure.... Someone it over in the Jackson Racing SC thread posting about a SC taking a shit?????

This may be a difficult thing to compare idk. But comparing all twin screw SC assuming pulley size adjusted so all of them made 7-8psi Would they all have relatively the same whp / 0-60 / 1/4mile times and would they all have relatively the same engine realibilty?
I know this isn’t a 0-60 1/4 mile car and autos are slow etc...

Probably not even possible but I’d love to get lowish 5s 0-60 and mid 13s 1/4mile at a reliable 7-8psi in an auto on pump gas.