I have googled until my fingers went number but I cannot locate any information. How small a pulley can you run before this compressor begins to get out of it's efficiency range? :read:
2.3 tvs efficiency range
- Thread starter Riptide
- Start date
Subbed, I know it's not nescessarily an indication of efficiency but VMP has had their Boss up to 875rwhp. I really wanna know how well these things work after 700rwhp. I guess with the smaller pulleys needed to make that power, the torque delivery is insane.
I'm running a 69mm w/ 5% overdrive balancer making 750 to 760whp with a Gen 1 Roush... I'm no where near running out of efficiency. Pulls hard to 7500rpm. I think Rebecca is running a 63mm & possibly 15% overdrive.
Still running the same heat exchanger and pump setup with it? How much have IATs suffered?
That is good news because I may need to pulley down from the 79.
That is good news because I may need to pulley down from the 79.
Original Roush heat exchanger and pump here. I've seen 800rwhp~ through the auto and stock manifolds on my Aluminator with my VMP Gen2. I made some tuning changes since my last run and plan on getting a clean pass before pushing for anymore power.
Rebecca Starkey's car has been over 900, it had longtubes and I know Justin has added cams now.
Rebecca Starkey's car has been over 900, it had longtubes and I know Justin has added cams now.
I'm running the stock single core heat exchanger, but I do have a trunk mounted intercooler tank. My tuner ran the stock pump, HE, and resivoir that came with the Roush all last summer. Same 69mm & 5% as I run. I went with the bigger tank to run back to back passes for True Street in the heat of the summer. Plus I drive my car to the track, so no generators w/ fans for me between passes...
I'm still refining my tune... I'm shooting for 9.50's on big & littles come fall!
I'm still refining my tune... I'm shooting for 9.50's on big & littles come fall!
Here is a efficiency map of the standard Eaton R2300 TVS, which would be a gen 1 Roush TVS, I'm porting the roush or the VMP gen 1 or gen 2 would have better efficiency
So how small a pulley can you run on the stock idlers and crank pulley before slip starts being a problem?
I want to pulley down to make up for altitude.
I want to pulley down to make up for altitude.
72mm won't slip... A 69mm starts to get tricky.
You'll need a shorter belt & possibly a 90mm idler pulley.
Talk to Justin at VMP
You'll need a shorter belt & possibly a 90mm idler pulley.
Talk to Justin at VMP
What fuel are you running? Are you trying to go higher on stock internals?
With a Gates K060815 belt and a Metco 100mm idler you shouldn't have any slip on a 72 and little if any on a 69mm.
If you want to run the 69mm with no slip at all on the 6 rib setup, check out the mosaleen idler. Its a bracket that adds an additional idler for a good bit more belt wrap.
When I was doing the math the 6 rib mosaleen idler will give very similar belt to pulley surface area to that of an 8 rib setup.
If you want to run the 69mm with no slip at all on the 6 rib setup, check out the mosaleen idler. Its a bracket that adds an additional idler for a good bit more belt wrap.
When I was doing the math the 6 rib mosaleen idler will give very similar belt to pulley surface area to that of an 8 rib setup.
Thanks I appreciate the suggestions. I will talk to VMP in a couple weeks after I track the car with the 79mm.
Will be on 91 and a stock long block. No need for more fuel with the smaller pulley at high altitude. Only if IAT becomes an issue and the tune will protect it if it does.
Will be on 91 and a stock long block. No need for more fuel with the smaller pulley at high altitude. Only if IAT becomes an issue and the tune will protect it if it does.
Splash in some Torco or some Lucas Octane Booster (The one that has MMT in it). This will add a good bit of knock resistance to your fuel and will get you more power. No tune change is required.
Keeping in mind 91 is garbage fuel for a high hp car, and running at altitude, I'd set my expectations low for the first time out.
Good luck!
Keeping in mind 91 is garbage fuel for a high hp car, and running at altitude, I'd set my expectations low for the first time out.
Good luck!
Thanks I got a case of Lucas in the garage. Planning on using it if anything for insurance when making passes. Believe it or not the car is seeing KS -2.00 over most of the pulls I've done in 2nd right now. So the fuel I've been getting may not be all that bad.
End goal is a mid to low 11 and you're right - expectations at this point are pretty tempered. We'll see what happens!
End goal is a mid to low 11 and you're right - expectations at this point are pretty tempered. We'll see what happens!
Per my conversation with Lucas, 3oz in 5 gallons of 93 octane will give you 96 octane. More Lucas does not increase the octane level. That is all I ever run in my car.
Great info I'm about to get a phase 2 setup for my truck and was wondering what kind of power they were good too
VMP said I can go with the 72mm pulley and recommended I add a 90mm idler along with it. I have seen the diagram on their website and it doesn't seem to indicate exactly which idler you replace on the 2011+ GT. Anyone want to share where the 90mm is supposed to go? I am assuming it is the top most one on the upper bracket.
Also won't need a re-tune from what I was told. Looking forward to installing and testing this once I get a baseline with the existing setup.
Also won't need a re-tune from what I was told. Looking forward to installing and testing this once I get a baseline with the existing setup.
Top most idler is the one you replace. I used a 100mm Metco before the mosaleen .
I like to run a tvs at 21-22psi max. On Rebecca's 11 5.0l with my blower we run a 20% OD lower, and 2.6 or 2.5 upper. With stock cams this would make 24psi, which was way too much, with comp stage 3 intake/stage 2 exhaust it makes about 18psi and we are able to run the smaller 2.5 or 2.4 pulley (which is what we would call a 66mm or 63mm in roush speak). The 20% lower is a prototype, it make 1 more psi than the 15% lower, but requires heavy modification to the accessory tensioner to clear.
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