$2008 Challenge Festiva, Help!

[gotrootdude]

Air dams are great if you don't have a smooth underbody. If you have a full underbody pan I believe they'll decrease your aerodynamics more than help it.

For stability in a race, I'd choose the dam over smoothing the underbody to decrease the air pressure under the car and stick it to the road. Then again, if you can put fins on the underbody to shoot air out the sides then maybe a smooth underbody would be best (maybe with a RWD)... Not sure which way to go on this...

[Safety Guy]

Gotrootdude wrote:

"Look guys, all I did was offer a few CHEAP suggestions that MIGHT offer some improvements. I didn't think I'd be ganged up on about it. After all, I'm not disagreeing with you that the suspension and engine come first."

I wasn't "ganging up!" Just wondering where you were getting your ideas, knowledge, etc.

That article series looks really good. I've known about the tuft testing for ages, but I've never done it. Looks like I should.

My only experience with aerodynamics comes from an air dam I made for my Chevette a long time ago. It was fairly deep in the first two piece version, then not so deep in the one piece second version (which also looked way better). All I can say is that it did indeed reduce the air pressure under my car because it did increase stability going over hills and kept the front end firmly planted! I never measured fuel economy or drag so I can't say if the increased frontal area overcame the air flow effects. I did have it on when I went on a long trip out west.

My plans for Festivas are to make another front air dam, but this time to do coast down or mpg testing to see if it makes a difference. With the FMS lowering springs installed, the air dam should not have to be as deep, and may both increase down force AND increase mpgs. Also, to block off at least half of my engine compartment area to wind intrusion. I have also thought of a modified front grille to better integrate the hood with the front bumper, but that would be more involved.

For winter, I'm also thinking of a solid front grille, for both aero and warm-up purposes.

Karl

[GenevaDirt]

lol....he's approved

[Seth]

got some images. il get more later.

1.6TDOHC Dorsey


1.6TDOHC Dorsey


1.6TDOHC Dorsey

its his car. hes currently waiting on approval for the board. i finally got him to get on here.

[Seth]

There was a car here that was built for that in 2003. It was Nightdwellers car. He recently sold the car to another members friend. It had alot of low budget tricks done to it. I know Nightdweller didn't build it but if you PM him he might be able to give some pointers as to what was done to the car.

Alright. well. the one that purchased it is my bestfriend. so im the one that can get pctures. ive been trying to get him to just come on the board he always talk about it his lazyness just kicks in. hah.

from what i remember it having.

Enginewise, swapped in 1.6T stock intercoolor festiva transmission.(id suggest g25, the guy who built it said he blew like 5 tranny in it had the tranny swap down to about 30 mins) he has an oil cooler.(il have to get pics its a relocated oil filter routed through a radiator) it has the stock trubio with and old HKS boost controller. he has the cone filter with air induction tubes running from three places, one from the cowl, one from under the car, and he added a little carbon fiber scoop right above were the cone sits. he has a oem blowoff valve.(im nto sure what psi its rated cause at stock 5-7 psi i dotn hear it.but id you step on it and powershift its loud. jsut dont hear it normal driving) thats all i can remmber about the engine right now.

Suspension wise, he has KYB GR2s all round with some brand of coil overs, all the bushings are red. maybe high durometer or maybe just replaced. front aspire brake swap. dual bolt pattern rims.(aspire and festiva) and in the engine bay he has a strut tower brace made from a F350 inner tie rod end.

an as for other thing i can remember, he has 2 APC racing seats. 1 five point harness, one four. half cage. or roll bar.(is only behind the seats nothing in the cockpit) 20 gallon fuel cell. two fuel pumps. a 1 gallon reserve tank fire extinguisher, a punch of little pods. boost guage, volts, oil pressure, EXC. big tach. momo steeringwheel. he had a thing on the bumper, like fins for downforce i belive. spoiler. he had a removable rack on the rof for toteing race wheels. passenger mirror.

geez i cant remember what else. il have to get pictures. hope this helps. and give you some ideas.

[gotrootdude]

Safety,

I use the yarn method for testing. Stick yarn on with tape where you believe the wind will change and a short run at lower speeds to see where the yarn goes. I find the vortex generators work much better underneath the car (where it's rough and turbulent) than they do on top as mentioned in this article in the testing conclusions: http://autospeed.com/cms/A_3061/article.html So, since I figured anything that would aid the handling of the car would help, I mentioned them. I can say from my results, since I do normally drive lower than 100+mph, that it does make a difference at lower speeds.

If I were in a race to win, I'd take any advantage I could get.

Look guys, all I did was offer a few CHEAP suggestions that MIGHT offer some improvements. I didn't think I'd be ganged up on about it. After all, I'm not disagreeing with you that the suspension and engine come first.

[Silv3rBull3t]

If you didn't know gotrootdude, at an AutoX the car will not see 60mph. Hardly worth the time, effort and $ for a challenge car. If we were talking road racing 100+mph, I would say you were right, maybe it should be looked into. Not in this application, especially not instead of adding power or suspension first.. -Kyle

[Kraig]

I think his 55 mpg is one measure of success.....

[Safety Guy]

Gotroot, I doubt anyone is questioning the value of cheap mods, or cheap aero mods.

What I personally find questionable is your strong belief that your "vortex generators" will work as stated, along with the cut in half clear plastic piping.

My understanding is that reducing the Cd of a vehicle takes quite a bit of work in either expensive wind tunnel testing or extensive coastdown measures.

What we think wind will do around a complex shape is not always what it WILL do around that shape in the real world.

Am I saying all that you described will not work? No. Just asking how you have measured its success, assuming you tried to measure it at all.

Think "peer review."

Karl

[gotrootdude]

BTW. Improving the aerodynamics of a automobile is part of racing and eco-modding. It has nothing to do with hypermiling.

[gotrootdude]

Dude, you'd be surprised how much small changes to aerodynamics with cheap material can do in racing. I accelerate much quicker with those cheap mods. Pie tin moon hubs would help as well but look a bit funny on a festy.

Anything that decreases the amount of air going under the car and those VG's under the body would really help the car stick to the ground around curves.

The only reason I suggested the steering knob is because it may help in a slalom course like on those you-tube videos and save your arms a bit.

Yeah, you could fiberglass custom sideskirts, like on RACE CARS, but time and money is a issue. Spend the big bucks on the engine, tires and suspension.

festivaWES, he asked for suggestions. I gave them. If he takes them fine, if he doesn't then thats fine too.

[festivaWES]

Well, I can tell you what I've done on my '89 Celica to to reduce drag and bring the gas mileage up to 55mpg. Along with a few suggestions.

On my Celica I bought cheap black plastic lawn edging from walmart, around $9, and used it to make the side skirts and bumper hang closer to the ground. It's cheap so it's not a issue if it suffers some road rash. I used the same stuff to make a ramp smoothing the front bumper transition and making a partial grill block. On the underbody, I formed a full pan out of aluminum sheet metal flashing. I also made vortex generators for the rear window and trunk transition and stuck some under the car as well to form a suction to hold the car down at high speeds. Very cheap, works great, looks decent. I took 2" diameter clear vinyl hose, cut it in half, and attached each half to the front of the wheel wells with the rounded part pointed outwards from the car. This guides the air flow around the tire instead of in the hub and the flexible tubing flattens out at higher speeds to close the gap between the tire and the body.


For the Festiva, I believe the largest weakness is the underbody and the negative pressure zone behind the car. A spoiler is a must, and I'd highly recommend a full underbody pan with VG's in a "V" formation under the car guiding air out the side skirts.

I'd also recommend a steering knob to help with handling. Something like this: http://www.dealextreme.com/details.dx/sku.12973

By the way yoiur gonna be racing...not hypermiling! Plastic gutter gaurd might do wonders in gaining MPG's but has nothing to do with racing.

[festivaWES]

Good luck...i couldn't spend the little amount of money and expect to compete.....I'd spend 2008 dollars on suspension and tires alone....lol

[Silv3rBull3t]

^ You're kidding right? Please tell me he's kidding...

For $500 for suspension/braking:

Aspire swap front and rear.
Homemade strut tower braces out of some plate steel and tube. (If you have a welder available)
Ebay Civic coilovers.
Used KYB GR2's.

For $500 drag:

I would go with nitrous but to each their own. Turbo, maybe Reich ECU and exhaust..

For $500 show:

Tremclad paint job
Wheels/Tires (Used R comp's for AutoX but I would use them for drag as well unless you can find some used slicks)

-Kyle

[gotrootdude]

Well, I can tell you what I've done on my '89 Celica to to reduce drag and bring the gas mileage up to 55mpg. Along with a few suggestions.

On my Celica I bought cheap black plastic lawn edging from walmart, around $9, and used it to make the side skirts and bumper hang closer to the ground. It's cheap so it's not a issue if it suffers some road rash. I used the same stuff to make a ramp smoothing the front bumper transition and making a partial grill block. On the underbody, I formed a full pan out of aluminum sheet metal flashing. I also made vortex generators for the rear window and trunk transition and stuck some under the car as well to form a suction to hold the car down at high speeds. Very cheap, works great, looks decent. I took 2" diameter clear vinyl hose, cut it in half, and attached each half to the front of the wheel wells with the rounded part pointed outwards from the car. This guides the air flow around the tire instead of in the hub and the flexible tubing flattens out at higher speeds to close the gap between the tire and the body.


For the Festiva, I believe the largest weakness is the underbody and the negative pressure zone behind the car. A spoiler is a must, and I'd highly recommend a full underbody pan with VG's in a "V" formation under the car guiding air out the side skirts.

I'd also recommend a steering knob to help with handling. Something like this: http://www.dealextreme.com/details.dx/sku.12973