803whp 730wtq naturally aspirated Prefix 9 liter

[Arizona Vipers]

Prefix finally wrapped up my engine, just dyno'd at 803whp and 696wtq LOL. (Dyno Jet dyno on hot and humid day)
See graph below with a layover over the previous dyno before the new pistons, cam and valvetrain
You can read more about the motor build here- https://driveviper.com/forums/thread...ession-pistons
This is in a 2950lb 2013 Viper LOL



DynoGraph9literHighCompression.jpg

[ViperGTS14]

Good lord! Congrats! Any pic's of the motor bay, curious how things are layed out and or what is different than factory especially regarding the intake/throttle body setup. Very interested in how heat is dealt with at this power range.

[txA&M08]

Good God that thing must rip

[J TNT]

Great numbers , Congratulations !
Yes keep us posted on heat management.
Thanks.

[ViperGeorge]

Great numbers , Congratulations !
Yes keep us posted on heat management.
Thanks.

Ditto on heat management. A friend just had Prefix do a 9 liter extreme in his 2016 TA 2.0. I don't know if he's gotten it back yet though. He had his headers Swain coated some I am curious as to how well that stuff works. His is not the high compression version though like I think AZ just got.

[blingnoring]

wow

[RedTanRT/10]

Wild graph AZ. Killer top end but the bottom end seems odd

I’ll go over there tomorrow and go for a test drive!! Any advice??

[Arizona Vipers]

at 730whp the car ran cooler than my stock ACR. You just gotta wrap your headers, I've said it 100 times. Coatings do nothing imo. Would you take your hand and grab your header with a coating on it? LOL. Your hand would stick and you'd be in the hospital.
Removing condenser is huge also as it blocks 60% of your radiator. Taking the beauty covers off the valve covers helps as well.

[ViperGTS14]

at 730whp the car ran cooler than my stock ACR. You just gotta wrap your headers, I've said it 100 times. Coatings do nothing imo. Would you take your hand and grab your header with a coating on it? LOL. Your hand would stick and you'd be in the hospital.
Removing condenser is huge also as it blocks 60% of your radiator. Taking the beauty covers off the valve covers helps as well.

More more more of this info please. Seeing you make this type of power and not have heat issues like us stock guys is giving me hope on not giving up the battle with heat. I've been frustrated in the FL weather this summer, my viper feels like its down at least 200 hp all joking aside. Are you suggesting even wrapping stock headers would help with heat? Please do show photos if you're willing, I know I'm not allow with heat issues and not sure what to do about it. Going to remove the valve cover covers like you suggested. Curious about the condenser your referring to by the radiator.

[Arizona Vipers]

More more more of this info please. Seeing you make this type of power and not have heat issues like us stock guys is giving me hope on not giving up the battle with heat. I've been frustrated in the FL weather this summer, my viper feels like its down at least 200 hp all joking aside. Are you suggesting even wrapping stock headers would help with heat? Please do show photos if you're willing, I know I'm not allow with heat issues and not sure what to do about it. Going to remove the valve cover covers like you suggested. Curious about the condenser your referring to by the radiator.

Send me a PM with the heat issues you are experiencing

[ViperGTS14]

Send me a PM with the heat issues you are experiencing

Thank you.

[serpent]

More more more of this info please. Seeing you make this type of power and not have heat issues like us stock guys is giving me hope on not giving up the battle with heat. I've been frustrated in the FL weather this summer, my viper feels like its down at least 200 hp all joking aside. Are you suggesting even wrapping stock headers would help with heat? Please do show photos if you're willing, I know I'm not allow with heat issues and not sure what to do about it. Going to remove the valve cover covers like you suggested. Curious about the condenser your referring to by the radiator.

Prob need to get your car dynoed to see what’s wrong. Been seeing your threads and posts about being down on power

[Arizona Vipers]

Prob need to get your car dynoed to see what’s wrong. Been seeing your threads and posts about being down on power

These cars do KILL power when hot. Timing starts getting pulled at only 205* water temp which is before the thermostat even opens LOL

[ViperGTS14]

These cars do KILL power when hot. Timing starts getting pulled at only 205* water temp which is before the thermostat even opens LOL

Assuming going away from the stock PCM / tuning has greatly helped with temp related issues with your build. Again that is impressive for NA power!

[ViperPete]

Holy crap. 200whp more than my car.... Must be astonishingly fast!!!

[serpent]

Only thing left to do is a dct. Because racecar

[outnumbered]

Dang!

[13COBRA]

I need to 9.0L mine, like I need a hole in my head...but wow, 800rwhp at <3000# is a ROCKET.

[Murpowa]

Unreal. Hoping for some video in the near future

[sharmut]

Forgive the ignorance, is the lower torque above 4k rpm expected?

[Voice of Reason]

Forgive the ignorance, is the lower torque above 4k rpm expected?

Do you mean lower torque BELOW 4k? That's not uncommon with a big cam, low end is often sacrificed to get bigger gains up top.

[Oh Three Z]

I agree with the others. The weight of your car combined with the power level is awesome. I have a 700/700 full bolt on Z06 that is a rocket. Yours must be insane. I’ve promised myself to leave my TA alone but your build is tempting

Congrats!!

[sharmut]

Do you mean lower torque BELOW 4k? That's not uncommon with a big cam, low end is often sacrificed to get bigger gains up top.

I was looking at the incorrect plotline, thought the orange was after the change.

[Arizona Vipers]

Forgive the ignorance, is the lower torque above 4k rpm expected?

There really isn't any loss. Looks like maybe 12 ft/lbs max from 3,000 to 3,500 RPM's, that's it. Which is amazing considering how much more power this cam is making
Also, I switched to 3.91's so this is exactly what I was expecting/wanting.

[sharmut]

There really isn't any loss. Looks like maybe 12 ft/lbs max from 3,000 to 3,500 RPM's, that's it. Which is amazing considering how much more power this cam is making
Also, I switched to 3.91's so this is exactly what I was expecting/wanting.

Should be fun for you to figure out how early you can roll into throttle and keep all that power to the ground.