2MCHPWR

hi - if you have a complete T1 suspension, if you add aero, will the T1 setup be too soft?

el es tu

from my research, cars running high amounts of downforce (that use the leaf spring setup) are running closer to 1000 lb/in springs

van steel and vbp both have higher rated springs to handle the load:
http://www.vansteel.com/index.cfm?fu...ups&Group=6001

http://www.vbandp.com/

jasonberkeley

PM Sent

froggy47

btlgrd

el es tu

one extra note - because the leaf springs are progressive (vs the linear nature of most coil springs used on coilover setups), the max rates end up needing to be significantly higher. With the leaf springs (in comparison to the constant rate of coil springs) you get more loss of ride height until you hit that max rate that the leaf is tested to. This is one of the reasons why a 500 lb leaf feels softer than a 500 lb coil, and the very reason why leaf spring users have to go further in spring rating. The other reason is because of the contact points - the leaf spring contact points to the lower a-arms are further inward than with a coil, so they have less leverage.

geerookie

I would think T1 springs would be more than enough to handle aero.
I'm running Penske 8760's with less than 400lb springs front and rear.
Mike just change to the same setup and has more aero than I do and ran a 1:23.8 this Sunday which broke the track record we set on Saturday.

geerookie

Less leverage would result in a higher wheel rate than a coilover with the same spring so the math doesn't support your point....unless I'm missing the point.

Olitho

I am running aero with T1 springs. It seems to do fairly well.

el es tu

Are you running coil springs? I couldnt imagine running a leaf spring that soft - the brake dive with the original front leaf springs (rated at roughly 400) is horrible. Also how much aero are you running? I have been planning on eventually switching to coilovers but have been concerned that the 400lbin springs that some kits use would be too soft.

shouldnt the spring have less effect the further inward the contact point on the a arm? ah maybe im just going nuts

RX-Ben

He is running coils.
Here is what a 400lb leaf (and the matching softy in the rear, and the matching toothpick sways) looks like with sticky tires around a turn: http://wrtsportsphotos.zenfolio.com/...4f15#h3c094f15

And up a hill (isn't this the rake that we are all aiming for???):
http://wrtsportsphotos.zenfolio.com/...4f15#h2f24f73b

froggy47

That's pretty funny/awful. Hope ya told the guy.

el es tu

ok so I had some time this afternoon to check the spring rate calc on the hyperco website : http://www.hypercoils.com/spring-rate-calculator/

as you move the spring outward you need a lower rate. also, when you raise the mount angle closer to 90 degrees like the contact point on a leaf setup, the necessary rate goes down...

all I can say is Im glad Im not a suspension engineer because I couldnt stand doing all that math every day!




that thing looks like its ready for takeoff!

0Anthony @ LGMotorsports

Depends on the track, depends on the aero.

Say you had a 1.5" splitter and a very small wing running a minimal amount of angle...you could be fine.

Compare that to a vented hood, flipped radiator, 5" splitter with tunnels, huge wing with a lot of angle, dive planes...... probably not so much..unless it was a slow track like say an autoX.

Also have to figure into it, how much is the car going to drop in ride height, if at all. Banking on the track? Tire clearance.....

Downforce typically increases with speed so plan accordingly.

geerookie

And here's what mine looks like with a 3" front splitter and a wing providing about 400lbs of downforce at 120mph.

http://www.youtube.com/watch?v=tg5ny...vVTyfQ&index=3

The guy that posted the video didn't know what he was talking about on lap times. In the DE I may have been running 1:32's with a passenger but in the race we were running 1:24's.

froggy47

vid link ng.

2MCHPWR

btlgrd

Anthony,
Approximately how much down force would your GT2 Splitter, Louvered Hood and GT2 Wing provide at 120 mph?

redtopz

This answers the question first hand. Oli's car is fast with basically the C5 world challenge aero setup. Might not be optimal, but it works well.

I think that has more to do with shocks and sways. Even stiff springs will do that with noodle bars and not enough rebound on the shocks. Not saying the springs are stiff enough, just adding to the picture.

Foosh442

I ran T1 suspension on my car a little over a year ago (ST2 car w/ aero) at Summit Point (Main) and I thought it felt decent. It was my first time there and I was on old A6's running mid 1:18's - I realize that isn't crazy fast but I was surprised how good the car handled.