bjhines

Pics are the only way we can verify the quality of this post.

The 01 Civic is higher and larger than the S-30 Zcar. So we still don't have a slick fish. We can get better with some more work fairing the windows, A-pillar, and drip rails. The wide-rounded shape of the IMSA flares could pay off in more ways than just reducing drag. The wheel wells could also use some work inside and out.

I for one would like to get some test data on relative pressures and flow at various points. I too was thinking that we could eventually get negative pressure under the hood... but the hood vents always flowed out not in. The tunnel has a test rig that we can use for this. We will have to make a project of preparing a hood as well as other areas to install the mass of hoses that must be attached to perform the tests. We will also need to think of some ways to achieve negative pressure under the hood. perhaps wheelwell and splitter designs would help... along with a well thought out airbox in front.

I have been pondering some of the finer points to this as well. The larger capacity finned cover will allow for the increased amount of oil better than the standard cover I am using in my system. I was told that a good cooler with low internal volume and -6 lines running to it, would not seriously impact fluid level in the differential. This was from a BMW car builder and they have relatively large capacity rear covers on all their diffs. He said to warm everything up for a few laps and then turn on the system pump. Then... Come back in and recheck the fluid-level with the pump running. That will account for oil expansion and the fluid in the cooler system. I originally thought I would mount the pump and cooler low in the car to keep them even with the fluid level in the diff. I seems that this is not very practical. I am also concerned with the fact that some of these pump's motors don't appear to be weather sealed. A check valve might slowly drain back while the car is stored for weeks of time. I also considered a draw through filter for the system(magnetic).

I had one of those Mallory pumps on a truck and it wore the motor brushes out yearly. after the second set of brushes the commutator was so grooved I chucked the pump in the garbage.

Just a heads up. you have to be careful when attaching hardlines to something that can vibrate or move even. You also have to consider that the lines can expand/lengthen with heat. Adding U-shaped radiuses and extra bends, as well as using hoses between components and the hard lines can pay dividends in long-term reliabilty. You should not use a compression fitting near the bend in a piece of hardline. The bending method can distort the tubing and make sealing unreliable. You might check up on some of info on the internet about routing and terminating hardlines.

There are so many safety features that modern cars have that the S-30 cars do not, that you cannot really compare them. I have seen an s-30 that was T-boned right in front of the rear wheel well. The car was squahed flat with the drivers seat pinned against the passenger seat. luckily the car was parked and no one was in it when this happened. The driver and passenger would have been crushed and pinned if they were in the car. Stiffening the car too much can be bad too. Think about crush-zones that are built into modern cars. The car can survive relatively in tact while injuring the occupants from shock acceleration. Modern cars have more headroom to keep occupants from hitting their heads on the roof and pillars. The S-30s are notorious for having little headroom on the sides. The foot-well areas are not reinforced and prone to crushing the driver's legs if the car is hit hard in the front door area. RUST, RUST, RUST... weakens the cars to the point that they are not even stiff enough to support their own suspension loads, much less IMPACT loads. The fuel tank is not potected and a serious rear-end risk on a stock Z car. aged fuel-bowl-to-jet lines on SU carbys are also prone to sudden failure and fires over the manifolds. The one overeaching fact that you cannot overcome even with modern designs is the light weight of the S-30 Zcars. The lightest car will take the brunt of the impact in a collision with a giant modern MINIVAN or SUV, especially if the other car has a truck frame. Another fact that simply CANNOT be overcome is the car's small size and low height. SUV drivers DONT SEE THE S-30 right beside them and will run you down. I drive relatively large cars and trucks for daily drivers. I have noticed that other drives RESPECT the size of my large vehicles. I never have problems with aggressive drivers cutting me off and pulling out in front of my large vehicles. The moment I get into my tiny little Z-car I am suddenly attacked from all sides by MORONS pulling out in front of me and bullying me around on the freeways. I never understood this rediculous attitude from other drivers. Hitting another car no matter what size is a serious offense. The fact remains. People will drive right over you when your car is smaller than theirs. IDIOTS abound. My duaghter will drive the largest vehicle allowed on the roads or she will ride the bus. If you want safety, buy a modern SUV that is 10 feet tall, bright red, and weighs 6,500LBS.

We had 2 blows where the hood popped up. One of them it popped WAY up. I recall someone saying it improved the numbers, but I don't know if it was enough time to get stable information. PS, I am out of town and can't really get online much until next week. I can't check numbers for any of this until next week.

I am definitely getting onto conjecture here. We can get some more specific info frmo the data we have. Further specific testing is REALLY required. We could not get into the level of detailed study we would like. We need a second date once we chew on the info we have for a little while.

hehe.. srry Mike!

I have placed my oil cooler ~10" in front of the radiator just sticking up. This may be the reason it had little effect on oil temps. My aero airflow is closer to being correct with all the sealing I have done. but because the air in the front opening is slow moving, stalled, and turbulent it is just going around the oil cooler with very little flow through. I will have to mount the cooler in a highspeed airsteam somewhere else, or provide ducting specific to the oil cooler. We will need to test this theory but... The same applies to intercoolers mounted in front of the radiator. They will have to be sealed to the radiator(in series) or the slow moving air will just go around them. This may not be a problem for you guys without sealed grill openings. The high velocity air moving through the grill opening provides enough force to move it through the intercooler before it dumps under the car. I am willing to bet that as soon as the intercooler crowd starts sealing their front openings they will start to loose intercooler efficiency. In this case you are going to have to provide another flow path specific to the intercooler or in series with the radiator. A good idea for intercooler mounting is to USE the gap between the airdam and the radiator crossmember as another exit-duct specific to the intercooler. You can simply mount the intercooler on the front edge of the airdam but duct the back side of the intercooler to only allow air to go between the airdam and the front crossmember. Here is a pic of what could help the intercooler crowd.

ok I hacked up some visuals for you guys. Bad airflow. Too much air can get in the front grill opening and around the restrictive radiator and ends up going under the car. Good airflow. Air forms a swirling,self sustaining pocket in front of the entire grill opening. This divides the air further away from the front of the car and allows air close to the ground to go over the hood instead of into the grill.

You have to think of the radiator as a flow limiter. It allows fairly free flow at 15MPH. The resistance to flow goes up very quickly as speed increases. At 80MPH the thing only allows a small percentage of the available airflow through. It effectively blocks airflow into the front of the car. Airflow goes around the entire front grill opening of the car.

The idea is just what it sounds like... sealed. If you were to put a piece of plywood in place of the radiator... and stood the car on it's tail... it should hold water flush to the grill opening. What is happening is that the radiator damn nearly blocks flow. Do not allow air that goes in the front of the car go ANYWHERE else without passing through the radiator. That makes the front of the car seem longer, lower, and smoother(weightless invisible G-Nose). More air from near the ground is able to go up and over the hood. If you allow air to flow into(and freely through) the grill opening then the airstream divides higher up(and closer to the car) and actually FORCES even more air into the grill opening(and under the car).

That tray will allow air to enter the nose, go up and around the sides of the tray and under the car. BTW that oil cooler might not get ANY airflow through it in that location. The air in a sealed inlet moves slowly and is turbulent. The oil cooler has no pressure differential in front or behind. The radiator IS HIGHLY RESTRICTIVE. If there is ANY path the air can take that bypasses the radiator it will dump under the car in HUGE quantities and ruin the airflow around the entire car.

We have had the whole balance idea drilled into us by the Aerodyn guys. That is really the problem. We would love to develop a package that works(serveral packages in fact). We had to satisfy the average Z owner in this testing series. We really did not have time to get into package development.

I can't wait to get the numbers worked out. My impression is : At 130MPH 1. The numbers on a poorly set up S-30 race car could be HUNDREDS of pounds of lift on BOTH ends and parachute loads of drag 2. A well set up S-30 could have hundreds of pounds of DOWNFORCE and reduce drag to near modern standards. This would have a huge impact on suspension design and tuning. These kinds of things have to be tested in the real world to ensure they do not cause instability in crosswinds and traffic.

We used headlight covers. In fact we used them on most of the combinations we tested. I recall they provided a noticable improvement. We will have to sort out the data to get the numbers. It seems that everything we tried showed noticable changes. We will have to do some number crunching to get numbers that represent real world results. Keep in mind that the BEST combination of parts we tried only approached the kind of efficiency and downforce that modern grass-roots race cars achieve. The tunnel operator told us at the end of the day that we had done very well to get our antique car to a point that it was approaching "raceable" efficiency and downforce. He made it clear that modern cars can still outperform our S-30 Z cars and they can take it a lot further. The Z cars have definitely tweaked his interest. We are setting up a meeting with the Aerodyn guys to discuss further modifications for our SECOND session. We might just figure out how to bring the S-30s back into competition with modern cars again. That would really piss off the SCCA who would yet again have to shift the Zs into a tougher class OR add a rule outlawing aero modifications of the types we employ.

The VGs were little dorsal fins about one inch tall and 2 inches long. little tee-tiny things that made instant, noticable improvements in drag AND improved the effectiveness of the rear lip spoilers.

One trend we found was that roofline modifications were HIGHLY effective. It takes only fractions of an inch to make BIG changes in numbers. The Supra style spoiler was on the list as well as another type of rear-upper lip. We simply didn't have time to test them. We did see noticable improvements from the smallest vortex generators. I would assume that the Supra style wing could be highly effective. It may turn out that Mike-KZ's supra spoiler is much bigger than it needs to be and may induce more drag than is worthwhile. The angles and size of the rear roof mods are HIGHLY sensitive and would require specific testing with multiple pieces.

If I remember correctly the G-nose was well installed and had good close fitting to the radiator core. JT1 will have to take a pic for me though. I was asses and elbows the entire day. I don't have a pic of the inside of the G-nose in my camera.

We have a lot of info to comb through. I just wanted to give you guys some of the impressions we had and trends that we found in our testing. Keep in mind that these were first impressions we gleaned from the raw data. When we have time to crunch the numbers we may find other surprising results.

The Gnose was a big dissapointment(for those who like the looks). No big benefit for all that $$$ weight hung off the far front end. Of course we hadn't figured out how effective sealing the radiator to the inlet was when we blew it. We might have made some improvements if we had know that then.

Yes Whale Tail was tested. We really need to look at the numbers on that one. As I recall it added an impressive amount of drag with relatively little downforce on the rear and significant uplift on the front end. I would not slam the door on the whaletail just yet. There are possibilities for both the Whaletail and the Pantera hatch on a car with wider hips(more horizontal area over the fenders). The whaletail we used was the big one. It may actually perform very well on the GTU fendered cars.

Imagine a hockey mask where the grill and bumper are. A 2"x6" slit in the middle for the radiator inlet is really all you need at ANY SPEED. The fact is... Failure to seal the airdam inlet to the radiator crossmember may stall air in front of the radiator and dump it under the car with a great deal of uplift on the front end. This not only screws up the aerodynamics of the car worse than no airdam at all... But it will also ensure that very little air ever goes THROUGH the radiator(causing overheating at speed). This has been observed by many people in the past. Sealing the inlet so that ALL AIR that does not go around the car MUST PASS THROUGH THE RADIATOR has been shown to have an absolutely stunning effect on so many levels. I have seen radiator inlet ducting that leaves openings on either side between it and the headlight supports. This is may channel air INTO the radiator but it still allows air to pass freely through the frontal opening and under the car. The only place air should go is through the radiator(which offers significant restriction to flow), into the engine air cleaner, or into the brake ducts. The aluminum plate on top of my airdam completely seals the front intake behind the grill. I must completely seal the sides and the holes in the support bulkhead now that we have seen what a huge difference this makes.