TravisJB Journal

Zeto · 04-05-2010, 08:37 AM

Quote:

Originally Posted by ChrisSlicks

I experimented a lot with tire pressure as well, with stock camber I was using 38.5 front, 35 rear, and after adjusting the camber I found that 36 front 34.5 rear was the ideal for maximum grip on my setup with RE-11's. Everyone will be a little different as it will vary depending on car setup, tires, and driver.

Thanks for the insight. i just mounted 285/255 RE-11's and I wasn't sure what tire pressures would be optimal. One question, wouldn't it be better to have a stiffer rear tire side wall with higher PSI to avoid rolling?

ChrisSlicks · 04-05-2010, 11:38 AM

Quote:

Originally Posted by Zeto

Thanks for the insight. i just mounted 285/255 RE-11's and I wasn't sure what tire pressures would be optimal. One question, wouldn't it be better to have a stiffer rear tire side wall with higher PSI to avoid rolling?

That all depends on how your car is setup. From the factory you have slightly more rear camber than front camber, and the rear can be adjusted to around -2.0 with stock suspension. It's typically the front that rolls the tire edge the most during cornering, it's the heaviest part of the car and experiences the most loading.

The pressures I quoted are if you have after-market sway bars installed with adjustable front camber. With stock sway bars there will be more body roll and you will need slightly higher pressures to compensate.

travisjb · 04-01-2010, 12:53 PM

and of course maximum perceived grip is usually different than best time around track... hoosiers are known for this

Zless@arizona · 04-04-2010, 10:35 PM

Quote:

Originally Posted by travisjb

and of course maximum perceived grip is usually different than best time around track... hoosiers are known for this

You have stumbled upon the holy grail of racing! Michael shumacher was able to dismiss the feeling, so that he could lap faster than anyone (minus a few bumping mishaps).

Zeto · 04-05-2010, 08:35 AM

Quote:

Originally Posted by Zless@arizona

You have stumbled upon the holy grail of racing! Michael shumacher was able to dismiss the feeling, so that he could lap faster than anyone (minus a few bumping mishaps).

This is really go to know.

travisjb · 04-04-2010, 11:26 PM

yeah, what's up with Shumi today ? rain... malaysia... supposed to be his day! argh

So, the Ford truck is great, but alternator went bad... took the opp'n to put in 2 dry cell optima red tops... going to upgrade as things break... the trailer lights aren't working right either, but not sure there's an upgrade for those

Will post some pics of the trailer soon... it's 99% set up now and I'm starting to get into the routine of using it and loading / unloading... really pleased with the purchase

I carved out the rear license plate area today with a die cutter and sawz'all... then installed a black s/s wire mesh w/ snap rivets... looks okay - my fabrication work isn't as good as Junior's!

Will be at the Import Tuner event with Sharif this Saturday at Firebird Main - he'll be driving his GTR

Sharif@Forged · 04-05-2010, 08:41 AM

Quote:

Originally Posted by travisjb

Will be at the Import Tuner event with Sharif this Saturday at Firebird Main - he'll be driving his GTR

Hey Travis, our GT-R crushed it's 4th gear two weekend's ago, and I had to scramble to find a new gearset. It doesn't look like the car will be ready for the Tuner Shootout.

Still trying to secure a backup car, but it's not looking very promising at this point. It's a shame because we were looking to improve on our 3rd place podium finish from last year.

travisjb · 04-05-2010, 10:21 AM

bah, who needs 4th gear ! lol

hope you get it sorted out !

travisjb · 04-09-2010, 09:20 PM

NASA AZ night event tomorrow... will be a packed event, good chance to test the car on a track I've not run before - Firebird Main

On of the engineers I work with has an extensive background in aerospace fluid dynamics and stopped by my house tonight to provide input. Here's the list we came up with - in no particular order:

a. replace headlights and tail lights with flat contoured aluminum sheets
b. likes the idea of a flat bottom but would prioritize side skirts ahead of that... goal is to be <3" off the ground on sides and have them extend out enough to be effective
c. he likes the idea of using the side scoops to generate vortices out the rear license plate area... recommending creating two counter opposing vortex generators and experimenting with the amount of airflow to determine optimal
d. doesn't like the front splitter design and instead recommends creating an entirely new front fascia with a gradual build up from lower lip tapering smoothly to hood... if keeping front splitter, doesn't need to stick out any farther and should be made more light weight
e. add a flexible 'skirt' from hood to windshield to eliminate the large seam that exists now w/o the plastic
f. create ducts in fenders behind the front wheels and determine a way for air to flow out of the wheel wells along the side panels / doors
g. reduce the volume of the wheel wells somehow hugging closer to tires
h. make the rear diffuser a lower priority
i. add small plastic fairings in front of the open windows to keep some of the air from rushing into the cockpit
j. optimize the angle of the rear wing... and make corresponding changes to rear suspension spring rates
k. feels the rear of the car is very "un-aero"... add vortex generators all along the back of the car to minimize the air separation... suggested I study some older aircraft designs that were retrofitted with vortex generators
l. also on the rear, he strongly recommended shave the 'hump' off the rear hatch - it is only cosmetic and is causing a major drag effect

Also, here's an updated project list:

- check steering column... very loose at hub... 2 screws are stripped
- update the splitter with t. washers and eliminate some weight
- fabricate air box for rear flow and setup diff cooler and pump
- weld / fill the holes on the rear deck
- shave weight on hood, rear hatch, bumper beams, rear structure, etc
- more permanent wiring for electrical accessories
- fix triple gauge... possible short
- fix SRM... possible short
- add front brake cooling
- swap radiator hoses for new SAMCO's
- resolve fuel starvation issue
- install longer wheel studs and open lugs
- alignment... -3.5 front / -2.5 rear, dial back caster to ~5
- install spa oil/water gauge in place of clock
- COBB tune... then dyno for NASA

Trailer to do's:
- patch holes in trailer... big one on side, some little ones
- install electric winch in trailer
- paint floor with "porch paint"

F250 to do:
- figure out why battery light keeps coming on

Mike · 04-09-2010, 09:51 PM

Quote:

Originally Posted by travisjb

f. create ducts in fenders behind the front wheels and determine a way for air to flow out of the wheel wells along the side panels / doors

Funny he mentioned that one. I work with a local corvette shop, MTI Racing, and they added the louvered Katech front fenders to their shop car and I don't remember how much speed they picked up due to reduced turbulence and getting the air out the top, but it was fairly significant.

FuszNissan · 04-09-2010, 09:44 PM

Good Luck

ChrisSlicks · 04-09-2010, 09:49 PM

Sounds like your project list just got a heck of a lot longer! Look forward to seeing what happens with those aero ideas.

travisjb · 04-09-2010, 11:01 PM

like this right ? should help draw air from under car and from wheel wells... may also help manage air flow separation and resulting drag around sides of car

Mike · 04-10-2010, 09:05 PM

Quote:

Originally Posted by travisjb

like this right ? should help draw air from under car and from wheel wells... may also help manage air flow separation and resulting drag around sides of car

No, MTI found in wind tunnel testing that those basically do nothing. The Katech vents are on top of the fender, wouldn't really work with our fender design though, but I'm sure something up top on the sides would work.

These vents/louvers:

Zless@arizona · 04-10-2010, 10:54 PM

Mmmm...wind tunnel testing!

Quote:

Originally Posted by Mike

No, MTI found in wind tunnel testing that those basically do nothing. The Katech vents are on top of the fender, wouldn't really work with our fender design though, but I'm sure something up top on the sides would work. These vents/louvers:

04-01-2010, 12:53 PM	#3 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 189	and of course maximum perceived grip is usually different than best time around track... hoosiers are known for this __________________ 2009 370Z #104 For Sale

04-04-2010, 11:26 PM	#6 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 189	yeah, what's up with Shumi today ? rain... malaysia... supposed to be his day! argh So, the Ford truck is great, but alternator went bad... took the opp'n to put in 2 dry cell optima red tops... going to upgrade as things break... the trailer lights aren't working right either, but not sure there's an upgrade for those Will post some pics of the trailer soon... it's 99% set up now and I'm starting to get into the routine of using it and loading / unloading... really pleased with the purchase I carved out the rear license plate area today with a die cutter and sawz'all... then installed a black s/s wire mesh w/ snap rivets... looks okay - my fabrication work isn't as good as Junior's! Will be at the Import Tuner event with Sharif this Saturday at Firebird Main - he'll be driving his GTR __________________ 2009 370Z #104 For Sale

04-05-2010, 10:21 AM	#8 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 189	bah, who needs 4th gear ! lol hope you get it sorted out ! __________________ 2009 370Z #104 For Sale

04-09-2010, 09:20 PM	#9 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 189	NASA AZ night event tomorrow... will be a packed event, good chance to test the car on a track I've not run before - Firebird Main On of the engineers I work with has an extensive background in aerospace fluid dynamics and stopped by my house tonight to provide input. Here's the list we came up with - in no particular order: a. replace headlights and tail lights with flat contoured aluminum sheets b. likes the idea of a flat bottom but would prioritize side skirts ahead of that... goal is to be <3" off the ground on sides and have them extend out enough to be effective c. he likes the idea of using the side scoops to generate vortices out the rear license plate area... recommending creating two counter opposing vortex generators and experimenting with the amount of airflow to determine optimal d. doesn't like the front splitter design and instead recommends creating an entirely new front fascia with a gradual build up from lower lip tapering smoothly to hood... if keeping front splitter, doesn't need to stick out any farther and should be made more light weight e. add a flexible 'skirt' from hood to windshield to eliminate the large seam that exists now w/o the plastic f. create ducts in fenders behind the front wheels and determine a way for air to flow out of the wheel wells along the side panels / doors g. reduce the volume of the wheel wells somehow hugging closer to tires h. make the rear diffuser a lower priority i. add small plastic fairings in front of the open windows to keep some of the air from rushing into the cockpit j. optimize the angle of the rear wing... and make corresponding changes to rear suspension spring rates k. feels the rear of the car is very "un-aero"... add vortex generators all along the back of the car to minimize the air separation... suggested I study some older aircraft designs that were retrofitted with vortex generators l. also on the rear, he strongly recommended shave the 'hump' off the rear hatch - it is only cosmetic and is causing a major drag effect Also, here's an updated project list: - check steering column... very loose at hub... 2 screws are stripped - update the splitter with t. washers and eliminate some weight - fabricate air box for rear flow and setup diff cooler and pump - weld / fill the holes on the rear deck - shave weight on hood, rear hatch, bumper beams, rear structure, etc - more permanent wiring for electrical accessories - fix triple gauge... possible short - fix SRM... possible short - add front brake cooling - swap radiator hoses for new SAMCO's - resolve fuel starvation issue - install longer wheel studs and open lugs - alignment... -3.5 front / -2.5 rear, dial back caster to ~5 - install spa oil/water gauge in place of clock - COBB tune... then dyno for NASA Trailer to do's: - patch holes in trailer... big one on side, some little ones - install electric winch in trailer - paint floor with "porch paint" F250 to do: - figure out why battery light keeps coming on __________________ 2009 370Z #104 For Sale

04-09-2010, 09:44 PM	#11 (permalink)
FuszNissan A True Z Fanatic Join Date: May 2009 Location: St. Louis Posts: 14,275 Drives: Pure Sex Rep Power: 543	Good Luck __________________ Mods: Too Many to list! LouFuszNissan ZDAYZ 2012

04-09-2010, 09:49 PM	#12 (permalink)
ChrisSlicks A True Z Fanatic Join Date: Mar 2009 Location: North East Posts: 6,203 Drives: 09 370Z Sport M6 Rep Power: 654	Sounds like your project list just got a heck of a lot longer! Look forward to seeing what happens with those aero ideas. __________________ Hotchkis ARB \| Stillen CAI \| Art Pipes \| Berk CBE \| Stillen AP Racing Brakes \| AE Performance Oil Cooler \| BC Racing ER Coilovers \| Doran Control Arms

04-09-2010, 11:01 PM	#13 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 189	like this right ? should help draw air from under car and from wheel wells... may also help manage air flow separation and resulting drag around sides of car __________________ 2009 370Z #104 For Sale

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