1/4 Runs at HRP on Sunday...

[Titan4x4Aggie]

This is a few days late posting, but I made 8 runs at the Houston Raceway Park on Sunday with eric the head (he was on his bike though).

I averaged around 15.5 sec @ 87.5 mph, with my best 15.485 @ 88.69 mph (shown below). Not bad for a big 4x4 truck with BFG's, but for some reason it always feels faster around town. Guess that's how it always is.

Still, I beat a stock '04 Ford F150 CC 4x2 w/ tow package He said his best was 15.85 sec.

I tried multiple launch techniques, and here is my opinion of the different ones:

1) power brake launch at 2500 - 3000 rpm: too much wheel spin. gained about 1 sec on my average time.

2) power brake launch at 1500 - 2000 rpm: what i used to get my average time; about the same results as a normal stop-light launch.

3) regular launch (punch and go): the way i got my best time.

4) regular launch w/ manual trans mode: slow shifts, gained about 1 sec on my average time.

I also checked my weight on the scales. Said I weighed 5520 lbs WITHOUT me in the truck. My cargo: subwoofer & bandpass box (~40 lbs), 24 pack of water (~25 lbs). That weight seems too high (about 300 lbs too much), even for 4x4 w/ offroad.

Scales could have been off.

[the head]

yeah the scales there are off. I don't know by how much, though. I think around 200 pounds.

[Finnattic]

Head,

I asked this in the Consolidation, Mods, Track Times, why do you think your running a good bit better 1/4 times with a modded CC vs. modded KC?

I'm under the impression the CC is heavier. Am I wrong?

Thanks,

Mike

[Titan4x4Aggie]

Originally Posted by Finnattic

Head,

I asked this in the Consolidation, Mods, Track Times, why do you think your running a good bit better 1/4 times with a modded CC vs. modded KC?

I'm under the impression the CC is heavier. Am I wrong?

Thanks,

Mike

every engine is different. nissan doesn't dyno each engine and scale them all down to the lowest one / advertised HP. i'm sure some might make more HP / torque than others due to many variables.

[Titan4x4Aggie]

also, you compared my truck to head's in the dyno / track time consolodation thread.

i have 4x4 and i dont think he does. i also have offroad.

i'm guessing the 4x4 drivetrain components [extra diff, 1/2 shafts, drive shaft, and transfer case] adds 200+ lbs and the offroad package [skid plates, tow hooks, large BFG tires] add 100 lbs.

that's probably an extra 300 lbs over a basic, $18K XE KC titan. I also have stereo package and added audio mods, and my dual exhaust is more than the stock i'm sure. all that adds up, probably pushing me over his CC weight.

[Finnattic]

Originally Posted by Titan4x4Aggie

every engine is different. nissan doesn't dyno each engine and scale them all down to the lowest one / advertised HP. i'm sure some might make more HP / torque than others due to many variables.

You mean to tell me Nissan doesn't dyno each engine and doesn't let them leave the factory until their exactly the same. Say it isn't so,

of course they don't , around 7 tenths and 2 or 3 mph is a good bit of difference.


Yeah I remember head saying he dynoed stock 330 rwhp.

[Finnattic]

Originally Posted by Titan4x4Aggie

also, you compared my truck to head's in the dyno / track time consolodation thread.

i have 4x4 and i dont think he does. i also have offroad.

i'm guessing the 4x4 drivetrain components [extra diff, 1/2 shafts, drive shaft, and transfer case] adds 200+ lbs and the offroad package [skid plates, tow hooks, large BFG tires] add 100 lbs.

that's probably an extra 300 lbs over a basic, $18K XE KC titan. I also have stereo package and added audio mods, and my dual exhaust is more than the stock i'm sure. all that adds up, probably pushing me over his CC weight.

Ah that's it, he has 2wd, and you 4, I see the light now...

[Titan4x4Aggie]

i also forgot to mention all that crap adds lots of rotating interia (even if it's only set on 2wd), along with rotating drag due to the extra fluids and other drivetrain losses, which will still be evident even if 4wd is not engaged, since the parts are always rotating (just not powered by the engine).

[Finnattic]

Originally Posted by Titan4x4Aggie

i also forgot to mention all that crap adds lots of rotating interia (even if it's only set on 2wd), along with rotating drag due to the extra fluids and other drivetrain losses, which will still be evident even if 4wd is not engaged, since the parts are always rotating (just not powered by the engine).

Good example off the possible differences it is.

I gotta ask I noticed you tried different launch techniques and spun some.

I know the manual says don't but have you tried or ran with 4wd? I wouldn't have a choice. Maybe with a real limited slip but abls isn't cutting it.

[Titan4x4Aggie]

Originally Posted by Finnattic

Maybe with a real limited slip but abls isn't cutting it.

i totally agree. only helps going around corners in dry conditions when the brakes are warm.

ss brake lines might help.

still, ABLS is worthless at the track and even worse offroading in mud.

[Finnattic]

Originally Posted by Titan4x4Aggie

i totally agree. only helps going around corners in dry conditions when the brakes are warm.

ss brake lines might help.

still, ABLS is worthless at the track and even worse offroading in mud.

Please don't get me started, that's def another subject...

I gotta tell ya it did do alright(once) going real slow through some muddy trails but give it some gas and forget about it...

[the head]

I think there are several reasons and I'll put them out there for consumption:
Houston Raceway Park is at like 7ft of elevation. We have dense air here almost all year long. This is the main reason, IMO, why I can run these times.
I stage shallow. Which is to say that I stop as soon as the second staging light comes on. This means I get a very, very short rolling start before the timers start to help get a good time. If it's a heads-up race, then I tend to stage deeper so as to shorten the length of the track. This doesn't sound like much, I'm sure, but it is the sum of the parts that add up.
I don't run with the tailgate, spare tire, front metal shield under the engine (because I have to remove it anyway to route my nitrous line), floor mats, jack, tools, nada - I even take out my CDs. However, I do usually leave the baby seat in just for effect.
I have a lot of runs and know what it takes to get the best 60' times on my particular truck.
I only run with an 1/8 tank of gas or less. Most of the time I have the low fuel light on when I get to the track. For reference, I weight about 180#.
Immediately after passing through the end of the 1/4 mile, I turn on my heater full blast. It is always on full blast unless I am in the burnout area and making a pass. The heater is just another radiator so I use it to cool down. I pop the hood whenever I'm stopped to let the heat out. I have not used ice on the intake yet because it gets a little messy and I don't want to have to deal with it.
I do run the throttle bypass mod for the cooling hoses. This has been subject to debate but I believe in it for a few reasons.
I run the front tires at 50psi.
All utility bed items are removed.

That's everything I can think of that I do at the track.

My mods:
Stock airbox with the inner tube cut out with a K&N drop-in air filter.
Banks cat-back exhaust.
Resonator mid-pipes replaced with custom made mid-pipes. These are stepped 2" coming out of the cats to 2.5" for the slight bends and then 3" to the Moroso Spiral flow mufflers (3") and then 3" to the Banks.
17" off-road wheels with P275/60-17s on them for about 3" less tire height and better gearing.
And the small wet nitrous system.

Remember when I first started out I was running 15.4s. I got 15.3s when I figured out how to launch it. 15.2s with the weight removal. 15.1s with the Banks. 14.9s with the mid pipes. 14.8s(14.79) with the shorter tires.

By the way, a Volant will be on the way shortly. I chose it mainly due to the fact it was "fixed" with a second generation box to make it better and the fact the engine breather lines are downstream of the mass air sensor and not in front of it like the K&N CAI does. I don't necessarily agree that it is the oil in the K&N filters that ruins the sensors (as I have run several on other FI cars with MA meters), but the oil vapor being sucked in from the engine intake vacuum is definitely not helping, IMO. I will most likely put individual breathers on the valve covers and plug the lines on the intake tube just to keep things "cleaner" going into the engine.

I have yet to dyno the engine. I made my hp calculations off of a performance calculator by inputting the weight of the truck and the MPH from the timeslips.

[RockyMtnTitan]

Originally Posted by Titan4x4Aggie

I also checked my weight on the scales. Said I weighed 5520 lbs WITHOUT me in the truck. My cargo: subwoofer & bandpass box (~40 lbs), 24 pack of water (~25 lbs). That weight seems too high (about 300 lbs too much), even for 4x4 w/ offroad.
Scales could have been off.

Those scales seem way off. I just weighed my CC 4X4 a week ago, and it weighed in at 5170 w/o me in it and with about 50# of tools in it. Published weight is 5046, so I think my weight is pretty close. Your KC should be even lighter.

BTW....Nice Times! Like you said....not bad for a big 4WD truck.....plus, you got to smoke a Ford!!

[Finnattic]

Originally Posted by the head

I think there are several reasons and I'll put them out there for consumption:
Houston Raceway Park is at like 7ft of elevation. We have dense air here almost all year long. This is the main reason, IMO, why I can run these times.
I stage shallow. Which is to say that I stop as soon as the second staging light comes on. This means I get a very, very short rolling start before the timers start to help get a good time. If it's a heads-up race, then I tend to stage deeper so as to shorten the length of the track. This doesn't sound like much, I'm sure, but it is the sum of the parts that add up.
I don't run with the tailgate, spare tire, front metal shield under the engine (because I have to remove it anyway to route my nitrous line), floor mats, jack, tools, nada - I even take out my CDs. However, I do usually leave the baby seat in just for effect.
I have a lot of runs and know what it takes to get the best 60' times on my particular truck.
I only run with an 1/8 tank of gas or less. Most of the time I have the low fuel light on when I get to the track. For reference, I weight about 180#.
Immediately after passing through the end of the 1/4 mile, I turn on my heater full blast. It is always on full blast unless I am in the burnout area and making a pass. The heater is just another radiator so I use it to cool down. I pop the hood whenever I'm stopped to let the heat out. I have not used ice on the intake yet because it gets a little messy and I don't want to have to deal with it.
I do run the throttle bypass mod for the cooling hoses. This has been subject to debate but I believe in it for a few reasons.
I run the front tires at 50psi.
All utility bed items are removed.

That's everything I can think of that I do at the track.

My mods:
Stock airbox with the inner tube cut out with a K&N drop-in air filter.
Banks cat-back exhaust.
Resonator mid-pipes replaced with custom made mid-pipes. These are stepped 2" coming out of the cats to 2.5" for the slight bends and then 3" to the Moroso Spiral flow mufflers (3") and then 3" to the Banks.
17" off-road wheels with P275/60-17s on them for about 3" less tire height and better gearing.
And the small wet nitrous system.

Remember when I first started out I was running 15.4s. I got 15.3s when I figured out how to launch it. 15.2s with the weight removal. 15.1s with the Banks. 14.9s with the mid pipes. 14.8s(14.79) with the shorter tires.

By the way, a Volant will be on the way shortly. I chose it mainly due to the fact it was "fixed" with a second generation box to make it better and the fact the engine breather lines are downstream of the mass air sensor and not in front of it like the K&N CAI does. I don't necessarily agree that it is the oil in the K&N filters that ruins the sensors (as I have run several on other FI cars with MA meters), but the oil vapor being sucked in from the engine intake vacuum is definitely not helping, IMO. I will most likely put individual breathers on the valve covers and plug the lines on the intake tube just to keep things "cleaner" going into the engine.

I have yet to dyno the engine. I made my hp calculations off of a performance calculator by inputting the weight of the truck and the MPH from the timeslips.

Thanks for the write up head, thought I was reading Road and Track online for a second.

I'll be a little more prepared when I eventually get to run because of guys like you... Happy Holidays