Duke Posted November 23, 2009 Report Share Posted November 23, 2009 I really like the new look. The truck does loose some of the sleeper status with the air dam and rear spoiler, so I think that they should be easily removable so you can really suprise people at times. Perhaps add a splitter to the air dam as well. You can even make it out of the "natural carbon fiber" you used for the bed cover. An interesting tidbit about the rear spoiler. My family is good friends with the old manager of the Rousch Craftsman Truck team. We were talking one day and he said that the rear spoilers on their trucks did virtually nothing until the truck got sideways. Once the truck was sideways and the spoiler was out in the airflow, it provided downforce. This made it really easy to avoid a spin because the rear would stick more when the truck was sideways. Quote Link to comment
Jester Posted November 23, 2009 Report Share Posted November 23, 2009 Looking good Bob. I too would like to at least see a splitter on the air dam. Even if it didn't really help. It sure would look killer. Quote Link to comment
Rubberman Posted November 24, 2009 Report Share Posted November 24, 2009 Hey Bob, did you get my pm with the pic? Quote Link to comment
Bob3 Posted November 27, 2009 Author Report Share Posted November 27, 2009 Hey Bob, did you get my pm with the pic? Yes - That looks cool. I'll pm you. Thanks Rubberman! I'm going to the track tomorrow to test my new AERODYNAMIC DEVICES! I'll post my findings. What I'm looking for is an increase in top speed at the brake point for turn #3. I will let you all know how the experiment goes! Myth Busters aint got nothin on me!:rollseyes: Quote Link to comment
Madness Posted November 29, 2009 Report Share Posted November 29, 2009 and then..... :mellow: Quote Link to comment
Bob3 Posted November 29, 2009 Author Report Share Posted November 29, 2009 I had a tow vehicle/trailer problem (I could only take one vehicle).:lol: We decided to take the new race car we just got for my son Bobby. I let the boys play and the MX520 sat in the shop at home.:( I'll try and get it out one day this week.:) Quote Link to comment
Madness Posted November 30, 2009 Report Share Posted November 30, 2009 damn! bobby got a new car? Miata? Quote Link to comment
denveratsun Posted November 30, 2009 Report Share Posted November 30, 2009 damn! bobby got a new car? Miata? PICS!!!!!:lol: Quote Link to comment
Bob3 Posted December 2, 2009 Author Report Share Posted December 2, 2009 (edited) OK . . . here are the results from the speed test today. First, the top speed from the track day in November was 92 mph, this is our baseline. 92 mph = baseline, NO air dam & NO bed cover 89 mph = with air dam & bed cover & spoiler straight up @ 0 degrees 90.5 mph = with air dam & bed cover & spoiler @ 45 degrees 92 mph = NO air dam, just bed cover, NO spoiler 93 mph = with air dam & bed cover & spoiler @ 75 degrees 95 mph = with air dam & bed cover & NO spoiler I think I'm going to try it again with an under tray. What do you guys think? BTW - I did a speed run around the one mile oval and got to 99 mph top speed with a time of 39.5 seconds = 91.14 mph average! Edited December 2, 2009 by Bob3 Quote Link to comment
lynchfourtwenty Posted December 2, 2009 Report Share Posted December 2, 2009 looks like the bed cover is a non factor, an its down to the air damn an spoiler.. altho it looks like the spoilers holdin ya back.. how was the handling compared to before with no bed cover???????? Quote Link to comment
Bob3 Posted December 2, 2009 Author Report Share Posted December 2, 2009 looks like the bed cover is a non factor, an its down to the air damn an spoiler.. altho it looks like the spoilers holdin ya back.. how was the handling compared to before with no bed cover???????? I could tell the spoiler was slowing me down. When I ran without the spoiler and air dam, just the bed cover it felt pretty good, but a little light on it's feet over 85 mph. With the air dam & bed cover it felt planted and stable at speed, better than before with no bed cover.:D Quote Link to comment
lynchfourtwenty Posted December 2, 2009 Report Share Posted December 2, 2009 nice! 1 Quote Link to comment
Skib Posted December 2, 2009 Report Share Posted December 2, 2009 how flat is the bottom of the 520 now? I wonder how much of a difference a belly pan and rear diffuser would make at higher speeds? Quote Link to comment
Jason Posted December 2, 2009 Report Share Posted December 2, 2009 The conclusion to me is that the bed cover is neutral. The rear spoiler generates resistance (does it generate any downforce?). The air dam seems to be the largest difference, the turbulence beneath the car must be pretty fierce ... Any way to get the spoiler down a tad more? Quote Link to comment
Dime Dave Posted December 2, 2009 Report Share Posted December 2, 2009 (edited) Bob, Undertrays are a good thing. The more you clean up the underside the better. Also add some rake to the chassis, it will add downforce. How about trying a simple front undertray (back to the radiator or cross member) and adding a 3" splitter to the front. These will add little to no drag and will add front downforce. There is a book out by Robert Tarzwell named "Practical Race Car Aerodynamics" available at www.MegaDawn.com. I have a copy and there are some very simple tricks that can help aerodynamics. The website's book description: "A very “hands on” practical handbook on how to improve the aerodynamics of your race car. Almost no math, lots of pictures and usable graphs and charts. Covers sedans and formula cars. Chapters on drag reduction, racecar aerodynamic tuning tunnels, diffusers, wings, splitters and spoilers." Edited December 2, 2009 by Dime Dave Quote Link to comment
denveratsun Posted December 3, 2009 Report Share Posted December 3, 2009 Dang Dave...good tips! Nice book too...:cool: So Bob...looks like there has been some good progress! I am STILL so pumped to come see it soon...:D Just not today...the temp is hovering near 10 and tomorrow is no better...supposed to drop to below 0 tonight...:eek: I'm splittin firewood man!:rolleyes: Quote Link to comment
Bob3 Posted December 7, 2009 Author Report Share Posted December 7, 2009 The wheels I've been running are 15x7 spares for the Miata race car. They stick out about 1" but they do not rub. I want them to be flush to keep the sleeper look. I bought a used set of Honda Fit 15x6 wheels for $150, they have been powder coated black. They sit in about one inch compared to the set I've been running. OLD Wheel on left rear: NEW wheel on right rear: I ordered a set of Datsun center cap stickers to cover up the "H" Quote Link to comment
fisch Posted December 8, 2009 Report Share Posted December 8, 2009 Neat choice Bob. Look forward to seeing some rubber on them and sitting on the ground! Quote Link to comment
Duke Posted December 8, 2009 Report Share Posted December 8, 2009 I was wondering what you were going to do about the wheels. These should look good with some nice meats on them. They may also increase top speed a little. I am sure I'm not the only one who would like to see you adapt some steelies to use the stock hubcaps for the ultimate sleeper setup. Maybe even some portawalls for that classic whitewall look... Quote Link to comment
Pacific coast Datsun Posted December 8, 2009 Report Share Posted December 8, 2009 Now you have Honda rims on the Miata suspension mounted to a Datsun body :D Quote Link to comment
Bob3 Posted December 8, 2009 Author Report Share Posted December 8, 2009 Neat choice Bob. Look forward to seeing some rubber on them and sitting on the ground! A friend of mine told me about: http://www.onlinetires.com I got 4 Hankook Ventus 195/50/15 tires shipped to my house for under $200.00 total!:thumbsup: They will be here next week. Then I'll get some pic's up. Quote Link to comment
denveratsun Posted December 8, 2009 Report Share Posted December 8, 2009 Sweet man! Wow...cool lookin rims! Great deal on tires too! How's the heater in the shop? Better be a good one man...it's been (expletive here) cold!:D Quote Link to comment
Madness Posted December 9, 2009 Report Share Posted December 9, 2009 Those wheels look pretty good :thumbup: Let me know how the exchange goes with that tire dealer. I've heard mixed reviews about them but they have the tire i need and they are a lot cheaper (about 20 bucks). Quote Link to comment
Umai Kakudo Posted December 15, 2009 Report Share Posted December 15, 2009 For TONs of really good DIY aero testing methods and information check out AutoSpeed.com Aero Testing Article Series Keyword Search Aerodynamic Keyword Search Manometer Keyword Search Wool Tuft With some yarn and a $40 used Magnehelic gauge and some knowledge you can make effective modifications based on real world data. Quote Link to comment
Bob3 Posted December 16, 2009 Author Report Share Posted December 16, 2009 I just got back from the PRI show in Orlando. (Performance Racing Industry) I got to meet Peter Brock, Mr. BRE! It was nice to sit and visit with him. He is very nice and took the time to visit with all kinds of Datsun fans. They had one of his 510's there on display. I'll get some pics up soon Bob Quote Link to comment
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