It's no debate that Topgun has been ahead of the game for quite a while, while other companies with bigger marketing teams and budgets were able to reap the benefits. I think that if Topgun had better marketing of its products with some revisions to its fit and finish it would definitely be more recognized and appeal to more people.

That's one reason I don't post anything anymore. Can't steal it if you can't see it.

Consumers benefit in a competitive market.

This might be due to the fact that Topgunz kit can use a smaller pulley to get boost down low, then bleed off extra boost at high RPM. Z1 kit has a normal Turbosmart BOV so it can’t do that


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what's stopping you from putting a solenoid in between manifold and turbosmart BOV to bleed off actuating pressure....

(or do you mean it just doesn't come setup like that out of the box?)

Yea exactly, it just comes with a normal BOV out of the box. Switch to a controlled BOV like Topgunz kit and I imagine the power would be very similar.


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the BOV doesn't need to be changed. just need to add a solenoid in line (pretty sure)

EDIT:
i think i'm wrong lol
topgun kit must use a wastegate as a BOV with top and bottom pressure fittings...right?
vs z1 using a BOV that generally only has a top fitting for vacuum reference.

In a short-sighted sense, consumers do benefit from the race-to-the-bottom pricing that is sparked by copy cats like Z1... but it is not the sort of competition you are thinking of.

It isn't like they are bringing competition in regards to development and progress to the platform. They are merely providing mildly reinterpreted versions of products you already had access to. They have contributed virtually nothing as far as performance achievements, problem solving, or innovation. Especially when you consider the scale of that company and their resources.

Compare them to businesses of a similar scale that specialize in other platforms such as Supras or GTRs or etc, and Z1 suddenly looks pretty weak sauce. With every other platform, the big heavy hitters are dropping innovation left and right; new/unique power adders, highly engineered intake manifolds, engine programs that solve problems, drivetrain engineering, etc etc. Meanwhile over here we have Z1, 20 years in on the VQ and they are releasing catback exhausts, cold air intakes, strut tower bars, cheap chinese coilovers, and copying anything they can get their hands on from small businesses. :icon17:

Yup, Mr. Squeeze and I have been talking about this for over a year. The same players have moved from the 350z, to the 370z and now to the new Z doing the same old thing. They will innovate to a point and then throw their hands in the air. Vinney Ten came back on the scene and ran a 8.65 in the quarter mile in his 350z this last week. Where are all the big players in the Z community? Selling/doing the same old thing.

The Z1 kit also uses a bypass valve on the wrong side of the intercooler. It sits on top and the hot charge air is coming in from the bottom meaning all of the HOT air coming from the supercharger is constantly being driven through the intercooler soaking it with heat and never giving it a chance to cool off. This is a terrible idea which will look good on the dyno since they let it cool down with the car off then hit it with one pull. On the street/track that intercooler will always be hot.

They also strung that motor out to 8000 rpm on their run which most guys are never going to do so the numbers are there for show...again.

Don't give them any hints. LOL

It's a damn shame more of the stuff they made for their time attack 370z didn't get produced. https://www.youtube.com/watch?v=JwZDloDWhL8

I ran my 370Z with Topgunz kit at autocross and can happily say, with the wastegate setup keeping boost constant through RPMs, it was SUPER easy to drive. Lots of torque out of corners and when I did have some slip, the car was as controllable as it was when NA.
Ended up at 7th fastest out of 94 on a car I haven't driven at autocross in YEARS, on a tire that wasn't a competitive autocross tire (not a super200 tw tire, not always in temp range)
https://www.youtube.com/watch?v=XQIFBq2x7kk

how does it sound when you're at 1/2 throttle but still decently high rpms?
Lots of BOV hissing?

I hear tons of BOV noises on my car, not much on the WG though.

I'm just waiting on TGZ to copy Soho and release a bypass valve setup; the BOVs always annoyed me, which is part of the reason I never ran them with any of my turbo'd vehicles lol

my TPGZ Rotrex SC Setup, at 3k+ rpm on no throttle/low throttle/decel type scenarios the BOV was a constant loud hissing that I found annoying, same with at idle when there was less noises covering it up.

I made a silencer for the BOV that has had zero negative impact to its functionality and dramatically reduced the volume in all scenarios so you really don't hear or notice anything ever now.

If I'm more than a quarter or 1/3 throttle, the BOV stays closed and is quiet. At very low throttle, that's where it opens and is noisy.

Black Friday Deals Are Here!

$500 off all 370Z/G37 Rotrex Supercharger kits! $6499

Dyno - Industry leading 800whp capable
Strip - 1/4 mile world record supercharged 370Z
Track - Super Lap Battle RWD Record holder and Global Time Attack RWD Record holder
Street - Tried and Proven.

I guess I'm reviving this thread.

I was under the impression that a smaller pulley creates higher top end power but less low end torque.

A smaller pulley on the SC means that it is spinner faster at all times, so you’ll be building boost at a lower RPM compared to a larger pulley… thus more low end torque. Theoretically this also means you have more boost at high RPM too, but the TSG Rotrex kit opts to bleed off additional boost at higher RPM and have constant boost after some set RPM. This would mostly be to protect the engine.


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Interesting.

I read or watched somewhere that a smaller pulley while producing more power by spinning faster is harder to spin. Similar to a higher gear on a bike. And that results in less low end torque. Is that incorrect?

For example here's a source: https://www.aimsindustrial.com.au/bl...ey-speed-ratio

The link in your source accurately states that a smaller driven pulley will turn faster and produce less torque. If you want to overlay this example with a supercharger, the engine is the drive pulley and the supercharger is the driven pulley. So this wouldn't at all imply that the engine torque would be lower with a smaller supercharger pulley.

But if you want to look at further... sure spinning the supercharger faster should increase parasitic load on the engine some, consuming a small additional amount of the engines output. But as we all know, the airflow (thus HP) provided by a supercharger far outweigh the effort it takes to spin the supercharger itself.

I bought a Innovate PSB-1 gauge and I have an updated EcuTek. Should I exchange the PSB-1 for a SCG-1?

Also, I am only going with innovate because I have the AAM flex fuel kit with the MTX-D gauge. Are there any better gauge options? I'd like to have only 3 gauges for E%, F temp, F press, A/F (ECB-1?), oil temp & press, and boost (controller?).

http://www.the370z.com/members/hapaz...-img-6492.jpeg

Finally made it to the dyno to complete my e85 tune. Very pleased with the numbers that my kit put down. 562/477 at 11psi. Big thanks to Aaron/Topgunz and Eugene at Enthusiast Auto Care!!

Nice, smooth graph

For the most part yeah! I'm trying to sort out a wastegate issue where it's letting out too much boost when it first opens. It's a little hard to see it on that pic but there's a dip down to around 9psi before it settles back around 11psi.

Build completed and tuned by Seb at Speciality Z
 

Hi Guys

Long time lurker and occasional poster here. Happy to say I completed my TopGun Rotrex SC build (incl waste gate addition) over the winter (Aarons prob even forgot i bought it its taken so long lol) and in June got it on the Dyno with Seb at SpecialityZ (cant say enough good things about Seb n Gregg, awesome professionals & enthusiasts to work with).

Kit was Aarons 93 Oct 500whp setup plus the Tial MVS wastegate, tuned to 511whp, 393 ftlbs torque w 11.6 psi WG spring (Dyno chart below), Dyno day Vid link https://youtu.be/EorNHSTusHc

Very happy with the build. Quality of the Kit was very high. Instructions (pdf) were good (could do with an update) and fitment was good for someone with experience working on cars etc, i,e, its not plug and play but this is working on modifying cars w aftermarket gear, shouldn't expect anything to be ;)

So thanks to everyone thats posted here, i used a lot of your knowledge sharing to select and build from :tup:

Now as we all know a build is never totally finished, heres some questions for my next bit of winter work,

- Blowoff Valve
Can anyone tell me what BOV Aaron supplied if ordered early 2023? Cant seem to find the model info.

- Pulley bearing failure
I've had premature belt pulley bearing failure on the SC bracket (anyone else had this?) and don't know what pulley I'm looking for so i can purchase a replacement. Can anyone tell me from the attached photo what info I need to get the correct replacement part please?

- Belt friction point
It looks like the belt is rubbing on something somewhere in the engine and i cant find it, really bugging me and starting to be a concern. There is a quarter inch wear band on the engine side of the belt and some dust getting thrown onto the hood, see photos. Anyone any idea what the contact point may be? Hoping its a known thing and not just my mistake on the install. Its only light friction wear, no heat or smell, but obv needs fixing soon.

That's it. Hope you're all enjoying summer driving, stay safe and thanks :)

Oh, also happy to answer any questions anyone might have.

K.

Thanks a lot for the writeup. I'm thinking heavily about going the SC route and posts like these are really valuable. Thanks again.

having had turbos in the past i really like the driveability of the SC. Feel free to PM me if you have any questions! Im not online much but ill get back to you when i do see it.