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NOT A TA
NOT A TA SuperDork
10/10/20 10:16 p.m.

Someone asked about a splitter that could pivot. Here's one I've been working on for my Firebird. The splitter can pivot up on what is essentially a giant piano hinge I made by using PVC tube inside square aluminum tube sections. The part below the engine remains flat. Splitter is 3/8" plywood and strong enough for me to stand on when mounted.

[URL=https://app.photobucket.com/u/NOTATA/a/ac949837-2452-4f6a-b3a7-1455f6a2f0b0/p/140458de-adce-469f-8620-a3b557084114][/URL]

 

Cedricn
Cedricn New Reader
10/13/20 6:09 a.m.
NOT A TA said:

In reply to malibuguy :

Notice in the video he doesn't consider a possible increase in pressure on the top side of the splitter nor does he mention the benefit of much lower pressure on the bottom of the splitter or lever length to the front wheels. Also doesn't take into consideration changes to airflow over/under the vehicle due to adding the splitter. He just uses pressures he measured on a stock Insight and uses math to make up what he believes. No mention of changes in drag, which I'd think he'd be yapping about since he's all about "road" cars not race cars. Seems like the point of his video is "Buy my book" but offers no credibility other than "I write book and do videos". 

He is largely right for a road car, where splitters have a very small area. But for a race car were there are limited ways of creating front DF the splitter can be an important component to get the aero balance right( also taking the leverage into account as you mentioned), adding DF at the rear is a much easier job, finding enough DF at the front to get good balance, not as easy. 

Superslowmonte
Superslowmonte
1/23/21 6:20 p.m.

Before I rush to Lowes and break out the cardboard for templates... does anyone have any empirical data that proves this made their car faster and is worth adding 15 lbs to the nose?

NOT A TA
NOT A TA SuperDork
1/23/21 6:40 p.m.
Superslowmonte said:

Before I rush to Lowes and break out the cardboard for templates... does anyone have any empirical data that proves this made their car faster and is worth adding 15 lbs to the nose?

On what kind of car with what other modifications?

Rick O'Shea
Rick O'Shea New Reader
1/26/21 3:57 p.m.

In reply to Superslowmonte :

My splitter, in combination with a 9lives rear wing, allows me to run lap times on two year old RS-4's that I previously could only run using fresh Toyo RR's. The grip, stability, and confidence through high speed corners is massively improved, despite the added weight. 

Superslowmonte
Superslowmonte New Reader
1/30/21 6:20 p.m.
NOT A TA said:
Superslowmonte said:

Before I rush to Lowes and break out the cardboard for templates... does anyone have any empirical data that proves this made their car faster and is worth adding 15 lbs to the nose?

On what kind of car with what other modifications?

 

A 2013 Mustang on stock struts, boss 302 springs, and roughly 100 lbs reduced. 18x10 wheels, hankook rs4

Superslowmonte
Superslowmonte New Reader
1/31/21 6:36 a.m.
Rick O'Shea said:

In reply to Superslowmonte :

My splitter, in combination with a 9lives rear wing, allows me to run lap times on two year old RS-4's that I previously could only run using fresh Toyo RR's. The grip, stability, and confidence through high speed corners is massively improved, despite the added weight. 

 

 

Are you losing any top end speed on the straights?

collinskl1
collinskl1 GRM+ Memberand Reader
2/1/21 6:30 a.m.

I race a 318ti with a plywood splitter and a fiberglass wing from Wingmen Aerodynamics. At the tracks I've run comparison tests with and without aero (Gingerman, Nelson Ledges, and Pitt Race) I see an average of 2 seconds a lap faster with the aero. My data shows 2.5-4.5 mph faster in each corner, while losing 3.5-5 mph on the straights.

Clock don't lie - Aero (when properly implemented) is faster, even with my underpowered car.

Superslowmonte
Superslowmonte New Reader
2/1/21 7:18 p.m.

Should i be worried about aero overwhelming my stock-ish suspension? Like the 100 mph t12 road atlanta in already out of travel.... but places like the esses at vir, i think i have some travel left. 

Superslowmonte
Superslowmonte New Reader
2/1/21 7:58 p.m.

Should i be worried about aero overwhelming my stock-ish suspension? Like the 100 mph t12 road atlanta in already out of travel.... but places like the esses at vir, i think i have some travel left. 

collinskl1
collinskl1 GRM+ Memberand Reader
2/2/21 6:58 a.m.

"It depends."

If the aerodynamic devices are effective, they are adding load to the suspension - which will use additional travel based on the springrate. How much is the next question to answer.

Rick O'Shea
Rick O'Shea New Reader
2/2/21 1:17 p.m.
Superslowmonte said:
Rick O'Shea said:

In reply to Superslowmonte :

My splitter, in combination with a 9lives rear wing, allows me to run lap times on two year old RS-4's that I previously could only run using fresh Toyo RR's. The grip, stability, and confidence through high speed corners is massively improved, despite the added weight. 

 

 

Are you losing any top end speed on the straights?

I see a 3-5mph loss on my E46 330 doing 115-120mph on the main straights. I make up for the lost time in the corners and braking. That works for me doing TT but decreased Vmax may become an issue in W2W racing.

So, i went with 1/4 instead of 1/2 with my new splitter. The 1/2 one was destroyed by a deer carcass. 

Its WAY more floppy and flexible than I expected. However,  for autocross i think it will be fine, and the weight savings is substantial. 

Am i underestimating the loads on it? Its limited to csp rules.

stafford1500
stafford1500 GRM+ Memberand Dork
2/8/21 10:08 a.m.

In reply to Dusterbd13-michael (Forum Supporter) :

For highway speeds or lower, with less than a few inches of extension, 1/4" will be fine.

Once you start getting more speed and/or more extension, the bending/deflection will get severe, possibly to the point that it can actually break from the loads.

Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
2/8/21 10:11 a.m.
Dusterbd13-michael (Forum Supporter) said:

So, i went with 1/4 instead of 1/2 with my new splitter. The 1/2 one was destroyed by a deer carcass. 

Its WAY more floppy and flexible than I expected. However,  for autocross i think it will be fine, and the weight savings is substantial. 

Am i underestimating the loads on it? Its limited to csp rules.

Can you wrap it in epoxy fiberglass? That could up the stiffness quite a bit. 

Dusterbd13-michael (Forum Supporter)
Dusterbd13-michael (Forum Supporter) MegaDork
2/8/21 10:50 a.m.

Oof. 

The thing is supported at four points by eye bolts,  fender washers,  and steel cable. Firmly bracked on the topside by the air dam, and protrudes about four inches on the front. Acts as a belly pan to the crossmember. 

Pictures if they help.

Should I be nervous? remove and remake? Send it and see what happens?

stafford1500
stafford1500 GRM+ Memberand Dork
2/8/21 10:55 a.m.

In reply to Dusterbd13-michael (Forum Supporter) :

The epoxy would help with stiffness, but I would go with paint and a well sealed leading edge and send it.

Make sure you have the template, in case you find another deer.

Dusterbd13-michael (Forum Supporter)
Dusterbd13-michael (Forum Supporter) MegaDork
2/8/21 11:45 a.m.

In reply to stafford1500 :

Has a thick coat of leftover valspar rilust tough on all surfaces. 

 

And i kept the "fixed" 1/2 splitter for a template. Cause i know ill need it again. 

triumph7
triumph7 Reader
5/16/21 10:03 p.m.

With current plywood prices some of these splitters would now be more expensive than the rest of the car!

 

wvumtnbkr
wvumtnbkr GRM+ Memberand PowerDork
5/16/21 10:30 p.m.

Lolz....

 

For those of you who are thinking of trying it...

Don't use the 1/2 inch pvc board.  It's tempting because it is weather proof and seems strong enough.

 

1 trip down the straight at Roebling Road and it broke in half and exploded....

 

Back to plywood for me!

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