[shinysun]

Hello ,

I tried to find the comp map for Whipple 2.9, but couldn't find it while there are bunch of TVS series' map.

Where can I find it?

The thing I am concerning is IAT goes up too high during WOT. Almost 160F even I sprayed Meth.
I am using 3" upper and 8" lower. almost maximized the rev for SC.
17333 rev @ 6500 rpm, 17.4 psi. (18000 max)
Usually almost all compressor's efficiency going very low around the boundary.

I assumed the efficiency is quite low now, so trying to figure it out with the map, but can't find.

Do I better use the bigger upper pulley? and advance the time more?
now I am using 21 degree.

[toohighpsi]

Peak thermal efficiency on the 2.9 is 65% at 8000 rpm and 1.9 PR (13.2 psi boost). By the time you reach 18000 rpm and 17 psi you'll be at <45% thermal efficiency and probably making quite a bit of heat.

You're not running a stock throttle correct?

21 degrees of timing isn't that far from MBT timing, only way to know for sure that a bigger pulley and more timing helps is to test it. I won't be surprised if you can make more peak power with the bigger pulley, but actual vehicle performance might be worse if you lose HP are under the operating curve in trade for a higher peak power number.

Let us know!

[NickeyMatt1LE]

More details on your setup? Engine? Stock heads? Stock cam? Headers? Have you checked to make sure the intercooler pump is running and pumping coolant? How long under wide open throttle are you running it to see 160?

[F419sr1]

Have you checked to see if you have still have air in the coolant system. It’s a pia bleeding it.

[Joshinator99]

Originally Posted by toohighpsi

Peak thermal efficiency on the 2.9 is 65% at 8000 rpm and 1.9 PR (13.2 psi boost). By the time you reach 18000 rpm and 17 psi you'll be at <45% thermal efficiency and probably making quite a bit of heat.

You're not running a stock throttle correct?

This is a really good point. Stock TB looks to be a big no-no with both Whipple & Maggie. You’re choking the inlet side, which raises your pressure ratio without flowing more air. Heat is the byproduct of that scenario too...

[toohighpsi]

700 RWHP is about the most you should consider with a 90mm throttle body on any PD blower. You could probably squeeze 750RWHP out of it but the pressure ratio will be falling into unfriendly areas. 102mm and a good intake/filter system will get you to 1K RWHP then you need the 112mm to go past that.

Remember that a PD SC is a simple multiplier, what ever pressure ratio you're set for, the manifold pressure will be = PR x inlet air pressure (at the SC rotor face). Maximum capability of the blower is almost always determined by the inlet tract to the SC (or max speed).

[shinysun]

Originally Posted by toohighpsi

Peak thermal efficiency on the 2.9 is 65% at 8000 rpm and 1.9 PR (13.2 psi boost). By the time you reach 18000 rpm and 17 psi you'll be at <45% thermal efficiency and probably making quite a bit of heat.

You're not running a stock throttle correct?

21 degrees of timing isn't that far from MBT timing, only way to know for sure that a bigger pulley and more timing helps is to test it. I won't be surprised if you can make more peak power with the bigger pulley, but actual vehicle performance might be worse if you lose HP are under the operating curve in trade for a higher peak power number.

Let us know!

Thanks for the advise.

No, I am running 103mm throttle.
I will test the bigger pulley.

[shinysun]

Originally Posted by NickeyMatt1LE

More details on your setup? Engine? Stock heads? Stock cam? Headers? Have you checked to make sure the intercooler pump is running and pumping coolant? How long under wide open throttle are you running it to see 160?

Stage1 TSP cam and ported heads. and 2" headers, and lowered CR.

It happened at 1/2 mile drag, the ambient was quite hot.

[shinysun]

Originally Posted by F419sr1

Have you checked to see if you have still have air in the coolant system. It’s a pia bleeding it.

Yap, I checked.

[Drsagacity]

Originally Posted by toohighpsi

700 RWHP is about the most you should consider with a 90mm throttle body on any PD blower. You could probably squeeze 750RWHP out of it but the pressure ratio will be falling into unfriendly areas. 102mm and a good intake/filter system will get you to 1K RWHP then you need the 112mm to go past that.

Remember that a PD SC is a simple multiplier, what ever pressure ratio you're set for, the manifold pressure will be = PR x inlet air pressure (at the SC rotor face). Maximum capability of the blower is almost always determined by the inlet tract to the SC (or max speed).

I was running 776whp with the stock TB. I am dialing it back only because well, I am still driving on street tires. What pressure measurement are you saying is a problem? Even when I ran over 800whp I saw injectors as the limiting factor, but curious because maybe there was something else too.

[Joshinator99]

Originally Posted by Drsagacity

I was running 776whp with the stock TB. I am dialing it back only because well, I am still driving on street tires. What pressure measurement are you saying is a problem? Even when I ran over 800whp I saw injectors as the limiting factor, but curious because maybe there was something else too.

Toohighpsi was referring to the compressor’s pressure ratio. A stock TB on a positive displacement blower at higher HP levels will choke the inlet side, raising the pressure ratio and increasing heat vs a properly sized TB. Very surprised to hear you’re running the stock 87mm TB at your power level.

[Drsagacity]

Originally Posted by Joshinator99

Toohighpsi was referring to the compressor’s pressure ratio. A stock TB on a positive displacement blower at higher HP levels will choke the inlet side, raising the pressure ratio and increasing heat vs a properly sized TB. Very surprised to hear you’re running the stock 87mm TB at your power level.

To run in the low 700’s, it only takes 8psi. Would be interesting to add the TB and see the difference.

[Joshinator99]

Originally Posted by Drsagacity

To run in the low 700’s, it only takes 8psi. Would be interesting to add the TB and see the difference.

Agreed, I suspect you’d see a nice gain given that your setup could really use the extra air IMO.