Vortech vs. Speed By Design-Need advice

[xuimod]

Originally Posted by Basket Case

I'm willing to bet the exhaust leak issue isn't a big deal and a fairly easy fix. Sme times with exhaust componenets if you don't get everything lined up perfectly before torquing you might not get a proper seal. and FYI, any performance mods for a supercharger including a header would delete the cats...

That's not true. You can change the pulley's on some (most?) Superchargers for an increase of like 30-40hp. Changing pulley's doesn't affect (and definitely doesn't delete) the catalytic converter.

Originally Posted by raven1231

Here is a terrible comparison of the dynos, I threw together between the OFT 300 dyno and shiv's SBD dyno. Both are on the OFT maps (vortech 9 psi, SBD 10 psi) Obviously there are a ton of potential issues when comparing these but I thought it might be interesting either way. The black lines are the differences between torque and the red are gap between horsepower. HP values on the left start at 50 and go up to 300 in increments of 50.


Looks like the SBD kit has the upper hand until about 5.5-6k where they even out.

That SBD dyno is not stock. It is for boost of 10.5 psi. The stock psi for the SBD kit is only 7.25 psi.

If you compared the stock SBD kit with the stock Vortech kit, they would be about even.

[raven1231]

Originally Posted by xuimod

That's not true. You can change the pulley's on some (most?) Superchargers for an increase of like 30-40hp. Changing pulley's doesn't affect (and definitely doesn't delete) the catalytic converter.



That SBD dyno is not stock. It is for boost of 10.5 psi. The stock psi for the SBD kit is only 7.25 psi.

If you compared the stock SBD kit with the stock Vortech kit, they would be about even.

Oh I thought that dyno was for Shiv's OFT tune....that's a little misleading then. Is there a dyno for how the kit comes (wastegate pressure) on the provided tune?

[Turdinator]

Originally Posted by xuimod

I have the SBD kit. If I could do it over again, I would go the SC route.

With the SBD kit I'm having issues with an exhaust leak and some carbon monoxide leaks into the cabin as a result. Bought a carbon monoxide detector so I know what the exact levels are in the cabin. Have to run the car's ventilation on circulate most of the time as a result. And when cabin carbon monoxide levels get too high for my liking (say over 50 ppm) I open the windows while driving. I had to crack the windows open when it was raining today, that sort of sucked.

When I get around to it, I'm going to bring the car to a muffler shop to fix the exhaust leak. Also going to install an aftermarket catalytic converter because almost all turbo kits delete the stock catalytic converter. With no catalytic converter, your car puts out extremely dirty exhaust fumes. If your car is parked in a garage, that's not a good thing at all.

So that's more money out of my pocket to fix the exhaust leak and install an aftermarket catalytic converter.

In general, all turbo's run off exhaust so during the installation you change the car's whole exhaust setup. The exhaust coming out of your car's tailpipe (as a result of the catalytic converter delete) will be much dirtier and if fitment of the install turbo's exhaust pieces isn't exactly right, there's a fair chance you might end up with an exhaust leak (which result in harmful gases entering the cabin; especially if you don't run your car's ventilation on recirculate).

In contrast, with SC, you don't mess around with the exhaust so there's almost 0% chance of exhaust issues as a result of the SC. And iirc almost all SC kits maintain the OEM catalytic converter so the air coming out of the exhaust is much much cleaner compared to turbo kits.

Our cars have two cats from the factory, the SBD kit only requires the removal of one.

Is your leak a result of the kit's poor fit and finish or poor installation?

[xuimod]

Originally Posted by Turdinator

Our cars have two cats from the factory, the SBD kit only requires the removal of one.

Is your leak a result of the kit's poor fit and finish or poor installation?

Where's the 2nd cat located?

I think leak is result of poor fit and finish. I actually am almost sure I know where it is (where the TP and Overpipe meet). Just haven't gotten around to bring car to muffler shop.

[Turdinator]

Originally Posted by xuimod

Where's the 2nd cat located?

I think leak is result of poor fit and finish. I actually am almost sure I know where it is (where the TP and Overpipe meet). Just haven't gotten around to bring car to muffler shop.

There is a cat in the header and a cat in the front pipe.


Good luck with the leak. There was talk of the flex joints on the SBD kit leaking, have you checked that?

[limitedblkwrx]

Originally Posted by nelsmar

1. No they don't. They add resistance that the rods need to push harder to force the exhaust out. Due to this choke point your end up with a chance of ectra exhaust in the cylinder post stroke. (Unless overlap which isn't ideal) this increases cylinder pressure / temperature and decreases efficency. Have you ever blown through one of those little party toys that make sounds when you blow hard? Yeah that's not "free". Blowers aren't as inefficient as they used to be. A large turbo gives less back pressure and lower egt and can be easier on the engine but then your spool lacks. People confuse this logic with compressor maps and think larger turbos make more power due to cfm rate.
2. Very true when using a recirculated dump tube. Very wrong when open dump tube. Sbd is recirculated.
3. Incorrect. On a dyno plot this is true in most cases. But transient response time suffers greatly. And a large efficient turbo suffers even more. Not to mention some
Blowed make full boost at sub 2k rpm...
4. Mostly true unles using a wastegates setup. However wastegates setups reduce efficiency.
5. True. But units like the vortech don't require oil and coolant likes this are less likely points of failure.

My supporting reasoning for the above: I have had both a high horsepower vortech setup and I daily drive a forged setup with a maxed out gtx30r. Which did I like more? My vortech. I hate transient lag. Not to mention O have also tuned probably 100+ cars on this platform alone...

The wastegate is internal on the SBD kit, so no recirculation is required because its dumped right into the downpipe from the turbo.

[nelsmar]

Originally Posted by limitedblkwrx

The wastegate is internal on the SBD kit, so no recirculation is required because its dumped right into the downpipe from the turbo.

A recirculated wastegate means it feeds into the downpipe... You are likely confusing the term recirculated bypass valve that pours into the inlet of the turbo. Like o said sbd is recirculated / internal gated. So it will flow through the exhaust. While wastegste is shut the car will be dramatically quieter. Once it starts to open it will start getting louder but still be quieter than NA / supercharged.

[limitedblkwrx]

Originally Posted by nelsmar

A recirculated wastegate means it feeds into the downpipe... You are likely confusing the term recirculated bypass valve that pours into the inlet of the turbo. Like o said sbd is recirculated / internal gated. So it will flow through the exhaust. While wastegste is shut the car will be dramatically quieter. Once it starts to open it will start getting louder but still be quieter than NA / supercharged.

Nope