The cog system I installed from the Dsport car . Is in the June issue of DSport Mag. They tell exactly what they went thru , why belts kept snapping . And how they got the project to work . Its basicly the same as I thought and said . Reduce the boost and rpm and it will work fine . The belts are just not wide enough to be strong enough to handle the trq. and power .
It also proves that it takes 14.7psi or more to produce enough power to double your N/A power with a SC . This setup for Derek made 37whp over doubling his N/A whp at 18psi [ 235whp N/A ] . With some pretty empressive engine , head , and exhaust mods

I had the blower off because the seals went bad . I also put a bigger pulley on the blower to reduce the boost some . Its up and running again and Im thinking of going to even one step bigger till I get a new EMS . Ive gone to redline a couple of times with this pulley , but its at around 20psi and its a bit much for the SS box . It only goes to 16psi

 

Hey Booger,

I'm glad you got the issue and that the setup is working out for you. We just didn't have the time to continue the R&D and complete the final tweaks necessary to get the cog setup to run correctly. I just got my car back yesterday and will have some updates soon with the JWT BB700 Kit and tuning by Sam@GT.

Derek,
DSport

 

The one thing I would love to find is a slightly shorter belt to run it under the idler pulley instead of on top . 20 - 30 mm shorter would be pefect . Running the 34 tooth cog on the jackshaft isnt doable with out notching the blower where it runs closest . So Im going with bigger pulleys on the blower instead.
Good luck on your setup !

 

sorry for the noob question, but what is cog?

 

Read that article too. Sucks that it took forever to have this article come out.

 

http://www.superchargersonline.com/p...30&tabactive=4

 

THANKS DUDE!!!

 

Took them a while didnt it

Derek
I PMed you about the BOV

 

I haven't read the new article yet, but the rule of thumb is is that every 14.7psi you make, you double your power.
That is under the assumption that the timing, intake temps, exhaust velocity, compression, etc are the same as they are when NA.
Chances are Dsport was pulling some timing compared to a bone stock G35, and also their compression ratio was lowered from the stock 10.3 to 9. Also there's the efficiency of the blower/turbo and parasitic loss to consider.

There's also other things concerning power other than the just air pressure.
NA and nitrous engines can gain power without increasing the air pressure at all with more aggressive timing and colder intake charges



I thought I'd post up what their compressor chart would probably look like based on Booger's logged psi numbers with the cog system since Dsport hasn't posted a boost chart. Obviously Dsport had a larger exhaust and more headwork than Booger, so the chart might actually be slightly lower than how it's graphed here, but not by much

They were shooting for 8000 rpms, but had to pretty much stop at 7500 rpms making something around 25-26 psi and then promptly snapping a belt

if you chart that out on the T-trim compressor map, you can clearly see that it's outside of the T-trim's most efficient range the entire time. It's probably somewhere in the neighborhood of around 68% most of the time, except possibly at the end where it might be 67-68%

If Dsport was able to reach their goal of 8000 rpms, you can bet the efficiency % would be even less, like maybe 66%

The T-trim's highest efficency is 72%

72% even compared to 68% is a 5.8% improvement or in this case about 25whp worth of power on the table going from 68 to 72% efficiency

What it looks like to me is that if Dsport could get the car to run all the way to 8000 rpms, it wouldn't really improve power much at all compared to 7500 rpms. It'd pretty much start capping off as the blower starts blowing hotter air as it runs into lower efficiencies. Of course they were spinning the blower pretty fast too which starts building up more heatsoak over time. 7500 rpms actually brought the plot off of vortech's chart and I had to expand the graph to show it. 8000 rpms would be even further off the chart.




As interesting as what they were doing was, after plotting it all out, you have to wonder just how much they thought things out with reving so high with so much boost on such small belts

If they ran this setup on a larger engine or toned the boost WAY down, the entire chart would pretty much lower itself and move further to the right as it brings the T-trim back into its most efficient range. The boost pressure would go down and overall airflow would increase due to the larger displacement

IMO I do agree with Dsport and Booger that if they didn't try to overdrive it and rev so high, they'd have a better and more reliable setup. Hell, it might even make similar power levels compared to reving it so high etc since it'd be treading closer to 70% efficiency the whole time instead of 66-68%

by contrast, my car's S-trim when plotted out is treading around 71% most of the time

 

LOL !!!!! And your point is ????? You think that running a few %'s more efficient is going to make your blower make that much more power ? Or you can double your N/A power with less psi ?

And I expect no less than a 1 ft. long reply from you too. So get typing...lol

Oh...and make sure you include some more of your ricer math !!!

 

Just what I thought . Put me back on ignore...you'll feel better