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Discussion Starter · #1 ·
So, my question to the forum is...I'm running 2.55 upper and 9.x lower pulley setup and boost is around 16lbs. Blower speed is over 23k rpm and at the end of a 1/4 mi run I see iat2 at 190 plus, depending on the normal factors. I'm stock cam, E85, bmr tank, Hx, and varimax pump. Now the car will be my daily driver and I'm having the lower changed to a 8.6 to lower boost. My thought is 1/4 mi et will be the same or better even with the loss of hp based on lower iat2 and pulling less timing. Sound right ?
 

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So, my question to the forum is...I'm running 2.55 upper and 9.x lower pulley setup and boost is around 16lbs. Blower speed is over 23k rpm and at the end of a 1/4 mi run I see iat2 at 190 plus, depending on the normal factors. I'm stock cam, E85, bmr tank, Hx, and varimax pump. Now the car will be my daily driver and I'm having the lower changed to a 8.6 to lower boost. My thought is 1/4 mi et will be the same or better even with the loss of hp based on lower iat2 and pulling less timing. Sound right ?
To answer your question, you lose about (~) 1% of
your HP for every 10° F of temperature rise in the
intake manifold.

But I think you would be much better off attempting to
retain about 15 psi of boost, and reducing your your
IAT's by improving your mass flow recovery system,
beginning with a better Intercooler, as well as moving
over to E-85, as it helps immensely to reduce internal
engine temps.

I would also suggest you change your camshaft, as
the stock camshaft results in a very limited valve lift.

This then results in a reduced 'Curtain Area', which is
highly restrictive to air flow.

Cheers,
RD
 
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Discussion Starter · #3 ·
All good information RD. I have the pulley already and the cam is to costly for my fixed income. I'm running E85 and I have a C&R hx. I install bigger cooling lines, removed the metal tubing, and my recovery is good. I don't use ice in the BMR tank because I routed the flow down from the tank to the pump in anticipation of an autocross or two. With hard turns I've heard of air getting into the loop and more bleeding issues.
You did answer my question...it appears at 190 degree iat2 I'm dropping about 10% of my hp which is about 60hp which is close the gain I get from running E85. This whole situation is from my own paranoia in search of daily driver reliability cause I have a heavy foot😁
 

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Back when I had a C&R HX, varimax pump, BMR reservoir and 2.38 pulley my IAT2's would be in the mid to upper 140's at the end of the quarter mile. Boost was 16psi and I was on E85. Sometimes the IAT2 would end lower if I was able to time the icing just right.

The C&R has a bleed valve, I would start there first. Sometimes it would catch air that wouldn't bleed via the BMR reservoir. My routing was also different from yours since I would "try" to ice at the track until I realized that tiny tank is not practical for icing. My routing was HX->Varimax->BMR Tank->Lid->HX to repeat. That's the routing for icing regardless of under hood reservoir or trunk tank.
 

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So, my question to the forum is...I'm running 2.55 upper and 9.x lower pulley setup and boost is around 16lbs. Blower speed is over 23k rpm and at the end of a 1/4 mi run I see iat2 at 190 plus, depending on the normal factors. I'm stock cam, E85, bmr tank, Hx, and varimax pump. Now the car will be my daily driver and I'm having the lower changed to a 8.6 to lower boost. My thought is 1/4 mi et will be the same or better even with the loss of hp based on lower iat2 and pulling less timing. Sound right ?
4.5 gal. Trunk tank. Temp at end of quarter depending upon the ambient usually 115 to 125 Fahrenheit Max. 1 varimax pump in the trunk only.
 

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Discussion Starter · #7 ·
I have never considered the trunk tank because it seemed to be for the hardcore drag racers however, I will look into as it may be less expensive than I thought.
I am dropping my lower to a 8.66 so I'll be at a 3.4 ratio rather than 3.6. I know for so many on the forum going backwards in power seems utterly absurd and boarders on insanity but I can justify my actions....the yellow highlite on the pulley ratio chart at 23,400rpm, not good for reliability. That's all I got.
 

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I have never considered the trunk tank because it seemed to be for the hardcore drag racers however, I will look into as it may be less expensive than I thought.
I am dropping my lower to a 8.66 so I'll be at a 3.4 ratio rather than 3.6. I know for so many on the forum going backwards in power seems utterly absurd and boarders on insanity but I can justify my actions....the yellow highlite on the pulley ratio chart at 23,400rpm, not good for reliability. That's all I got.
Chiseled performance in Florida will make you anything you want. 45 gallon tank is probably 200 to 250 plus your fittings plus 50 feet of 3/4 inch heater hose. It can be done for for approximately four hundred bucks in
I have never considered the trunk tank because it seemed to be for the hardcore drag racers however, I will look into as it may be less expensive than I thought.
I am dropping my lower to a 8.66 so I'll be at a 3.4 ratio rather than 3.6. I know for so many on the forum going backwards in power seems utterly absurd and boarders on insanity but I can justify my actions....the yellow highlite on the pulley ratio chart at 23,400rpm, not good for reliability. That's all I got.
Chiseled performance in Florida will make you any tank you want. A four or five gallon tank should be 200 to 250 plus fittings and a 50 foot roll of 3/4 inch heater hose. You should be about 400.
 
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