Whipple 4L performance question

ItsDocJim · Aug 13, 2017

Hello everyone. I am a new owner and am expecting delivery of my 95. I had a 4.0 liter Whipple added. I was wondering what the performance expectations would be.

what are people getting for HP?

What is the top speed of a 05 with a 4.0 L Whipple?

Would like to know performance without breaking the car to find out myself

spartan · Aug 13, 2017

What car did you buy?

ItsDocJim · Aug 13, 2017

05 Red with white stripes.

2112 · Aug 13, 2017

Boost a pump too?

ItsDocJim · Aug 13, 2017

All I know so far is the whipple, upgrading the stereo, clear bra and butterfly doors and about 1350 miles. Car should get here in about 2 weeks.

twobjshelbys · Aug 13, 2017

Congratulations on your new toy! Gotta be like a kid on Christmas eve waiting for Santa to come!

To answer your question: The car will go faster than you can legally go anywhere except on a track (even without the Whipple). However, you will get to the speed limit faster than anyone around you.

Enjoy!

nota4re · Aug 13, 2017

DocJim, the drivetrain and virtually everything else is identical between the 2005 and 2006 cars. The 4.0L Whipple was available with a variety of different pulleys which would serve to provide designated boost levels. I suppose the most popular were the sizes that yielded either 19psi or 21psi. With either of those the RWHP was likely in the 800HP range and pretty near the GT's max fuel delivery capability. The boost-a-pump is a device that resembles a small stereo amplifier and it will drive the fuel pumps at 12-18v providing a little more volume of fuel for higher HP applications. Think of it as providing some "headroom" for the stock fuel system. 4L Whipple cars will typically break the 200mph barrier in the standing mile venues. Not sure what final top speed would be but I would say in the 230's.

ItsDocJim · Aug 14, 2017

Trying to figure it out for vanity plates:
"220 MPH"
"225 MPH"
"230 MPH"
"240 MPH", etc

"DATE NT"

Xcentric · Aug 14, 2017

"300 MPH" would impress more people.

Sent from my SM-G950U using Tapatalk

nota4re · Aug 14, 2017

You should take some time to get to know your GT - regardless of how many cars you have driven or your propensity (like all males) to rate yourself as a well above average driver. Unlike many exotics of yesteryear, the GT has near instant torque and it doesn't take much to get the tail end to come around. Large Whipple + Unknown Date Code on Tires + New Owner = BE CAREFUL.

PeteK · Aug 14, 2017

Ditto what Nota4re said. You best take the car to a large empty parking lot and see how it behaves when you stomp on the go pedal. Not something you want to find out the hard way on a public road.

2112 · Aug 14, 2017

Regarding the vanity plates.

I would get a feel for the INSANE amount of attention you are going to garner before choosing a plate that might just add to that and maybe not all positive.

mmlcobra · Aug 14, 2017

nota4re said:
You should take some time to get to know your GT - regardless of how many cars you have driven or your propensity (like all males) to rate yourself as a well above average driver. Unlike many exotics of yesteryear, the GT has near instant torque and it doesn't take much to get the tail end to come around. Large Whipple + Unknown Date Code on Tires + New Owner = BE CAREFUL.

Seat time and a mature attitude is important in being safe in a car at this power level.
Congrats on your new purchase.
You are going to love it!!!
Best,
Mark

ItsDocJim · Aug 14, 2017

I agree completely. It has been a long time since I raced my father's Pinto at 120 MPH on the back roads in high school (hopefully the statute of limitations has expired). My charger was pretty stable at 150, but I quickly realized I was passing minivans filled with kids at 100 MPH faster than they were going and didn't want them to panick and go into a ditch, so I never did that again. I spent the summer with my brother's GT at about 630hp, so I got familiar with some of how to expect it will behave, but I know to be careful.

I do not want to drive it 230 mph (well, actually I do, but it would need to be a closed course with a long straight). Mostly, I just wanted a real # to put on a Vanity plate. (300 mph is impressive and I give the other GT credit, but I was looking for something believable for MY car).

My brother once said his smaller Whipple put out 740 hp and the car was capable of 240 mph, but Shelby said my larger Whipple would be about 740 hp and 220 mph. I just didn't know what the other forum members heard/knew or experienced.

Nafod · Aug 14, 2017

The numbers from Shelby will probably be spot on. He would know the "pulley" and resultant boost. Which would normally equal approx. top speed.
Probably not a 3.9 final drive car as there are few of those, but this would also affect top speed with normal RPM.
Mile event will be where you probably will be able to find the final number.
Congrats on the new arrival.
Bruce

NorthwoodGT · Aug 14, 2017

Guess I'm not clear on what you want to do. have a driveable street car or have the bragging rights to a top speed bullet? I've installed the 3.4 Whipples on a couple of my cars and for the street, it's plenty. the issues of going to larger units is the fuel system as mentioned before. when you get into the 4.0 and larger you then have to increase fuel pump capacity, fuel lines, injectors and other components. the 3.4 litre Whipple give you approx. 700 HP with the proper tune which for me is nice on the street without all the fuel mods. top speed? not a clue nor will I ever find out. JMHO

ItsDocJim · Aug 14, 2017

NorthwoodGT said:
Guess I'm not clear on what you want to do. have a driveable street car or have the bragging rights to a top speed bullet JMHO

One of the questions I always get at car shows with my brother's car is "what is the top speed?" I figured other people on the road would ask themselves the same questions. The plate would tell them.

Specifically to the question, both. Drivable with bragging rghts&#55357;&#56860;

daytrayd · Aug 14, 2017

Honestly, I cant tell if youre trolling us or not.

NorthwoodGT · Aug 14, 2017

daytrayd said:
Honestly, I cant tell if youre trolling us or not.

lol!

ItsDocJim · Aug 14, 2017

Sarcasm... usually that comes from me. Seriously, I am not trolling. I am just excited to finally have one of my own (in about 10-14 days depending on closing on home equity line and how long it will take Shelby to arrange delivery). I am just trying to figure out vanity plates so I am ready to register it when it arrives. I also don't want to talk Hp and top speed at a car show and have someone call BS on me. Just looking for the real numbers.

If I knew how to post pics here I would put up pic of brother's or the one Shelby sent me of mine getting loaded on to the truck to go to him for upgrades.

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