Whipple guys with 20 percent od and 2.8 oor 3.0 pulley

Would like to discuss and learn from people with similar builds. Anyone else running this setup? Was at dyno day yesterday and some reason my curve went flat around 6k rpm trying to figure out why.

Anyone with similar combo care to discuss?

Youre entirely out of blower. A 2.8" blower pulley puts you around 18k blower speed at 6500rpms. I have tested over spinning the 2.9L blower and it didn't do much good at all, they're not like a TVS. The 18k rpm rating from Whipple is not just for longevity and bearing life, its also where they found the blower maxes out efficiency wise. Spin it faster and you'll get a disproportionately higher intake temp versus the increase in boost, and you will lose power.

I would stick with a 3.3 (peak 18k rpms around 7300-7400), I don't think you will pick up much power going smaller than that, itll just be pushing hotter air.

TooSoonJunior said:

Youre entirely out of blower. A 2.8" blower pulley puts you around 18k blower speed at 6500rpms. I have tested over spinning the 2.9L blower and it didn't do much good at all, they're not like a TVS. The 18k rpm rating from Whipple is not just for longevity and bearing life, its also where they found the blower maxes out efficiency wise. Spin it faster and you'll get a disproportionately higher intake temp versus the increase in boost, and you will lose power.

I would stick with a 3.3 (peak 18k rpms around 7300-7400), I don't think you will pick up much power going smaller than that, itll just be pushing hotter air.

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If you have your Intake Air Temps under control, you will definitely make more power spinning the 2.9 over 18K rpm.

The proof is the amount of cars out there that do spin it higher and race competitively, or the cars that are out there making over 1000 whp or more using more than 18K rpm blower speeds.

Would love to see more details on those overspinning it, especially the supporting mods needed to keep temps in check. In my experience I have not found much luck overspinning, it was a marginal increase in torque for flatlined top end.

So then BMR whats your take on the OP flatlined power curve north of 6k rpms?

TooSoonJunior said:

Youre entirely out of blower. A 2.8" blower pulley puts you around 18k blower speed at 6500rpms. I have tested over spinning the 2.9L blower and it didn't do much good at all, they're not like a TVS. The 18k rpm rating from Whipple is not just for longevity and bearing life, its also where they found the blower maxes out efficiency wise. Spin it faster and you'll get a disproportionately higher intake temp versus the increase in boost, and you will lose power.

I would stick with a 3.3 (peak 18k rpms around 7300-7400), I don't think you will pick up much power going smaller than that, itll just be pushing hotter air.

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Good info thanks!!!

Decisions decisions, because it does pick up in the mid range, gets me to 6500 rpm, and maybe its better to shift at 7k anyways vs. 8k?

What else could I do to squeeze some more power out of my combo? I think I've done about everything? Is only option to go turbo next? If I go turbo, there will be issues with the manual right?

What is the end goal for this car for you? If you can shift the thing decently you should be deep into the 9's already.

Couple options are to spray some methanol injection pre blower, itll give you massive cooling, a pound or so more of boost, but will need some careful tuning given you are already running e85.

You could also spray a nitrous shot, might want to also consider spraying pre-blower to help with temps, should pick up a NICE amount of torque and power doing so.

I assume youre running an ice box already?

Other than those options, everything else will give you minor improvements, so your next big step is to switch to a kenne bell (I always like Whipple better than KB but KB offers larger capacity blowers as a bolt on setup) or like you said go turbo.

In either case if you goal is to go fast down the drag strip, you may want to consider swapping to an auto, even for your current setup it WILL go faster down the strip.

TooSoonJunior said:

Would love to see more details on those overspinning it, especially the supporting mods needed to keep temps in check. In my experience I have not found much luck overspinning, it was a marginal increase in torque for flatlined top end.

So then BMR whats your take on the OP flatlined power curve north of 6k rpms?

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Cobra Jets and COPO Camaros.

http://www.hotrod.com/articles/exclusive-factory-stock-fast-blast-2017-gatornationals/

See the attached pic. I would say none of those cars are spinning 18K or less.

BMR Tech said:

Cobra Jets and COPO Camaros.

http://www.hotrod.com/articles/exclusive-factory-stock-fast-blast-2017-gatornationals/

See the attached pic. I would say none of those cars are spinning 18K or less.

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Thanks bud - without knowing exactly the pulley sizes these guys run its tough to guess. What you can know for sure that with the weight (3300lbs), 3 speed auto trans, 3.89 gears, 15" slicks, it is certainly going to take less power than a street car would need to dip deep into the 8's.

But I agree evidence seems to say they're overspinning it.

One thing for sure, all the Copo, cobrajet, and dragpak whipple kits have a MUCH thicker intercooler brick. When they finally released the dragpak version of the 2.9L kit, we were able to measure and it was nearly 1" taller than the base whipple kit. Made a SUBSTANTIAL difference to temps.

3575lbs

Math says thats 1100~whp.

They are also running 8500+ engine RPM.

TooSoonJunior said:

What is the end goal for this car for you? If you can shift the thing decently you should be deep into the 9's already.

Couple options are to spray some methanol injection pre blower, itll give you massive cooling, a pound or so more of boost, but will need some careful tuning given you are already running e85.

You could also spray a nitrous shot, might want to also consider spraying pre-blower to help with temps, should pick up a NICE amount of torque and power doing so.

I assume youre running an ice box already?

Other than those options, everything else will give you minor improvements, so your next big step is to switch to a kenne bell (I always like Whipple better than KB but KB offers larger capacity blowers as a bolt on setup) or like you said go turbo.

In either case if you goal is to go fast down the drag strip, you may want to consider swapping to an auto, even for your current setup it WILL go faster down the strip.

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End goal: I'd like to make 1000rwhp and then see how fast I can get it down the track. I am not running an ice box. What would be the benefit of that? Cool inlet temps? (Still learning)

I have given some thought to swapping to auto. And to hard top. Have considered trying to find one real cheap swap everything over then sell this vert. But haven't made any final decisions yet as I'm pretty far upside down in this car right now (Still owe 45k)

doodguy said:

End goal: I'd like to make 1000rwhp and then see how fast I can get it down the track. I am not running an ice box. What would be the benefit of that? Cool inlet temps? (Still learning)

I have given some thought to swapping to auto. And to hard top. Have considered trying to find one real cheap swap everything over then sell this vert. But haven't made any final decisions yet as I'm pretty far upside down in this car right now (Still owe 45k)

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Youre very close, so I would say stick with the Whipple for now.

Few things to check over, do you have a log of the pull where you flatlined up top? I assume youre a 10 rib, so little chance of belt slip but a log will for sure show it, and also confirm there is nothing else going on (timing, fuel, IATs, etc)

Second, yes an Icebox will definitely help you eek out more power. Basically you bypass your normal coolant routing of Blower to small auxiliary tank with pump, to the heat exchanger, then back to the blower, and instead go from the blower to the icebox which has its own pump. You fill the icebox with water and ice, and you greatly lower your blower temp and intake temps, allowing you to run more timing and have a cooler charge, both will make more power. Remember making boost results in heat, there is no way around it, once you produce the boost and heat, anything you can do to cool it back down is a plus. The idea of nitrous or methanol injection preblower is you start off with a lower temp to begin with, so the end result is a cooler boosted charge. Just a different way of getting to the same result.

As BMR is pointing out, seems like the big dragster guys are overspinning their blowers and not seeing the same drop off in power as you have seen, so you have to try to find the bottleneck. Air filter too restrictive? Belt Slip? Tune problem?

Yes 10 rib. Lund said log looks good. It's capping at 21psi and stopping.

I don't think there's a tune issue. Belt slip is likely the culprit. Gonna get smaller belt see what happens. Also debating get 2.8 pulley see what it does.

get in touch with anthony ballard... hes making over 1000 0n a built motor...

The difference between Ballard's combo and [MENTION=17037]doodguy[/MENTION] is Ballard uses Stage 3 Comp cams. However, Ballard has stock 11-14 heads compared to Doodguys S550 heads.

I am not sure the smaller pulley will do much in this case, as the car made similar peak power on the 3.0 pulley as it did on the larger pulley....with the primary difference being that it made more power in the mid range with the 3.0 pulley.

Very interesting stuff.

BMR Tech said:

The difference between Ballard's combo and @doodguy is Ballard uses Stage 3 Comp cams. However, Ballard has stock 11-14 heads compared to Doodguys S550 heads.

I am not sure the smaller pulley will do much in this case, as the car made similar peak power on the 3.0 pulley as it did on the larger pulley....with the primary difference being that it made more power in the mid range with the 3.0 pulley.

Very interesting stuff.

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Confused... did we not just talk through that you can overspin the blower and make more power? Sounds like you are now agreeing the blower is out of gas and cant push more air. Or is there something else in doodguy's setup that is holding it back from utilizing more air?