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old01cobra

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Alright, got my combo dyno'd. All supporting mods etc, E85, 3.12 pulley on a 10 percent od 4v with a v1 ti feeding it with a 8rib. I also only had the big ass MT 28x11.5 bias tires to put on it and its running 4.30 gears. She put down 677/530 at 11lbs. Tuner is the best in the business and im still battling belt slip pretty bad and this was acknowledged by the tuner himself. Boost was falling due too coolant, we got that corrected and the last 800 rpm looks like a sin wave now due to slip.

You guys think this is all this blower is going to do or do you think I still have some head room? Blowers ratted for 950 hp. I know the 28inch tires and 4.30's are eating up some power how much who knows but the 28's are getting replaced for smaller street tires for the next dyno. Im obsessive with this crap and I will keep dumping money into her just want moral support in thinking it will be for something. Goal was 750+whp but reality is reality. Bigger blower time?
 

blownstang4.6

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How is it only 11psi? Are you losing like 10psi through the intercooler? I'm making 12psi with a 3.12 on an S trim, with stock crank pulley, and stock 6 rib.
 
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old01cobra

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Volumetric efficiencies. My engine is probably 110+ percent. If your stock you’re probably like 85ish. The engine is extremely efficient.

Figure with the normal 12 percent loss and the extra loss for the 4.30 and 28 inch tires it’s gotta be 800+flywheel hp right now.

Was hoping someone with some ti trim experience could vouch for the 950 hp they’re rated at so I’m not chasing a magical number.
 

old01cobra

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also I am getting belt slip. I was only expecting like 14 psi out of the blower because the engine alone was making over 1/2 of what the blower was rated for as it made 460rwhp NA.
 

01yellercobra

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I'd get it back on the dyno now that the belt slip is fixed. See where you're at then go from there. Are you spinning it to the max RPM?

FWIW, I ran an older T trim on my big bore stroker. At max RPM I only saw 14psi. Never put it on a dyno, but I ended going with an F1A because I wasn't a fan of the Vortech.
 

old01cobra

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Yeah for now I thought I’d see 14 16 on the setup not 11. I’m making the ac compressor adjustable to take up slack. Will see if it helps.....

Yes it’s a 3.1 pulley with a 10 percent od crank spinning too 7000 so it’s maxed.

I was looking at Prochargers but that step ratio is steep for how I have the car setup. Right now I can still run the 4.30s and she hauls.. With a 28 tire I should have enough to hit mid high 130mph traps. That’s the obsession with 750+rwhp that should easily put me in the 10s
 

01yellercobra

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Yeah for now I thought I’d see 14 16 on the setup not 11. I’m making the ac compressor adjustable to take up slack. Will see if it helps.....

Yes it’s a 3.1 pulley with a 10 percent od crank spinning too 7000 so it’s maxed.

I was looking at Prochargers but that step ratio is steep for how I have the car setup. Right now I can still run the 4.30s and she hauls.. With a 28 tire I should have enough to hit mid high 130mph traps. That’s the obsession with 750+rwhp that should easily put me in the 10s

Why wouldn't you just get a shorter belt if that's what's needed? That's a lot less effort than fabricating the a/c compressor.

All the step up ratio means is you can use a larger blower pulley to hit higher impeller RPM. IIRC I ran a 3.9" upper with a 12 or 15% crank pulley and it put the F1A in the high 60k range at my shift point. I was aiming for hitting 80% of the max RPM and it was right there.
 

old01cobra

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tried the different belt idea first. Need something like a 111belt and no one makes them.

As far as the step and rpm range the Vortech fit better at this time. Plus I personally like the mounting bracket on the Vortechs better on our cars. But the Biggest factor was it was a lot cheaper than a d1sc or d1x. Got the bracket and blower for 2800 out the door new.
 

jaxbusa

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Check the specs of the intercooler if you remember what brand and model you have. Might be a pain but you could try to bypass the the intercooler temporarily to see if it’s the problem. I don’t think I’ve ever heard of belt slip on an 8 rib at that low of pressure.

Vortech specs for V1 TI:
55,000 impeller, 26 psi, 1400 cfm

Using Vortech’s calculator:
3.1 unit pulley, 10% crank pulley (7.25) , 7,000 rpm= 56,479 impeller speed. If my input is right you are right at max impeller speed.

See if your intercooler is rated around 1400 cfm.


Sent from my iPhone using svtperformance.com
 
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old01cobra

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Intercooler is a treadstone trv25 it’s rated for almost 1500 cfm. So it’s matched to the blower really well. Plus it’s only 1 or 2 degrees above ambient temp at this time so it’s working.

Yeah the belt slip on 8 rib surprised me also. That’s why I went with it figuring it wouldn’t. But what I’m learning is it’s not just the psi that causes the slip. It’s also the power output of the engine being applied to the crank. 800 hp (roughly) is a decent amount so it’s still transferring that level of power to the crank even if it’s just 11lbs. Vmp cobras are running 20+ to make that power. From my understanding the power applied to the crank pulley is what mainly causes slip as the initial serpentine pressure is applied at that point and the back pressure psi is just the inefficiency of your engine/combo.

I’ve never dealt with this power level and low boost. It’s acting like a LSx motor and they slip also around these levels with lower belt tension issues like I have. But they have adjustable idlers and crap to make up for it and we don’t.
 

jaxbusa

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Thanks for sharing. It seems like you might have to step up to a bigger blower and a cog belt. I have a Vortech V2 TI with that same intercooler on my stock 2 valve. I wanted something that I could use on my stock car and grow into. I was hoping to get 650 to the wheels on E-85 and heads. I’ll be a little disappointed if that’s all you get out of it. Keep us posted.


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old01cobra

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You’ll hit 650rwhp when you want too. I’m at 677rwhp now and that’s with some pretty bad belt slip and those goofy bias slicks definitely didn’t help. Tire swap alone should put me over 700whp. Regardless I’m pretty sure when the kinks are worked out I should be able to hit 750+. I can live with being off the blower rating by 100 or less. Mark that up too reality of blower loss due too engine setup etc. Will see. Was hoping someone maxed out a newer ti setup. SLO said he got 14psi off the old t on a similar setup. New ti is worth about 125 hp over that blower so hopefully I can get this too see 15 16 lbs. that should put me over my mark. I’ll update when I get it returned. Thanks to those that replied appreciate it...
 

01yellercobra

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I should've added that 14psi was on a 5.3L big bore stroker. Stock 03 heads, Ford GT cams, and stock 01 intake at that time. Along with Bassani mids, catted X, and Stingers. So it flowed decently. With the F1A and a ported 01 intake I saw 19psi at redline. Never saw a dyno, but estimates were 650-700.

FWIW, I had alignment issues in the beginning. Once I figured those out and went to a Thump tensioner I never had an issue. Pulled like a damn freight train.
 

DSG2003Mach1

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old/weak tensioner perhaps?

have you checked gates catalog from their website looking at effective lengths? I swear there are some right around that 111" mark but maybe Im wrong.
 

old01cobra

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Mines on a 5.3 bb/s ported 03 heads fr500 intake etc. Man if you’re making 19lbs with the f1a you’re definitely short changing yourself. If you still have it get it on the dyno you’re well above 700... I’m there on 11lbs. You’ll be 800 plus lol. Nice....

Do you recall where your alignment issue was? I could look at that but I think I’m good got about 700 miles on it with no issues other than slipping.
 

old01cobra

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Brand new single bolt ARS tensioner basically thump they’re the same company. I looked at the catalog didn’t see anything in the 111 in 8 rib
 

01yellercobra

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Mines on a 5.3 bb/s ported 03 heads fr500 intake etc. Man if you’re making 19lbs with the f1a you’re definitely short changing yourself. If you still have it get it on the dyno you’re well above 700... I’m there on 11lbs. You’ll be 800 plus lol. Nice....

Do you recall where your alignment issue was? I could look at that but I think I’m good got about 700 miles on it with no issues other than slipping.
That car is llooonnnggg gone. Got tired of little issues creeping up. I still have the shortblock though. For future use in my 04.

I had to move the power steering pulley a bit and then shim the idler on the passenger side of the blower. It was the ribbed one. It would pull the belt towards the engine and cause it to run on the inner lip of the blower pulley. It would look like I used a knife to slice off one rib.
 

old01cobra

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Yeah I don’t have any issues like that yet. Thanks for the replies guys much appreciated...
 

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