so after the last outing my front splitter is absolutely knackered. A giant hole in the middle under the crash box, the wear pads either side pretty thin and one side flush. A few small holes at the lip underneath. And stress cracks in the fibreglass either side right where it the underside ducts up behind the crashbox.
The working theory is that those stress cracks had appeared over time and then at silverstone where it's regular top speed and running over 160kph, along wiht the fact that i was running the lower dive planes, the forces ground out the underside and created the huge hole along with all that additional wear, which would make the cracks worse, viscious cycle.
i don't know whether to try and repair or give up and get a new diffuser which is very expensive, £1k+.
is this normal wear and tear for a front diffuser? after a few years of running it just becomes a disposable part and you have to get another?
Or is there some way to minimise the risk of it happening again?
i'll take some pics tomorrow when i pull it off the car..
A giant hole in the middle under the crash box, the wear pads either side pretty thin and one side flush
I wear down the sides of mine, mainly from hitting the curbing and rumbles. I have never worn a hole in the middle under the crush box, so something might be going on there.
I will build up the ground-down areas with glass mat and polyester resin. If the damage is extensive, then I replace it. I also replace the jabbrock plates as needed.
You want the front diffuser to be stiff with no wiggle when you grab ahold of it. If it moves easily, that needs to be addressed. If the car is set up with correct ride height and the diffuser and stays are stiff, nothing should drag at high speed with high downforce. If you are not hitting high curbing, then your diffuser should not drag even under high lateral loads.
What David said. I wear the side jabbrock plates too, and recently had Dean Jones Racing repair mine. I run (from advice from David said a long time ago) with just the lower dive planes, and I regularly see 250+kph (on a good lap I'll be there 3 or 4 times depending on traffic).
But never a hole in the middle. That's weird...
i think the diffuser had been set far too low for whatever reason. When i complained of the porpoising/vibration we noticed that the diffuser was too low and adjusted it back up.
Maybe by then the damage was already done, i don't know.
i removed, fixed, and refitted. Everything seems stiff and sturdy, infact putting it back on was super fiddly trying to align everything up.
Hopefully the fibre filler + layer of fibreglass to strengthen the sides where it had completely cracked has done the job.
I also drilled a pair of small holes on either side just infront of the bars where the underside comes up to meet them and tie wrapped it for that additional bit of help.
I'll recheck the front diffuser heights one more time once i stick it on the trailer....which is the only 'flat patch' i've got at home.
@davidf what height is your splitter from the ground, both the front and rear sides of it, please?
@davidf what height is your splitter from the ground, both the front and rear sides of it, please?
I usually shoot for about 45mm (50mm is OK too) from the ground in front, and then whatever it takes to make a good fit with the nose sides so that it aligns in place without bending and without requiring pulling to fasten the zeus fitting. So maybe 55-60mm in the rear sides.
You did a nice repair. I have not seen a radical have any wear on that center rear area of the diffuser like yours. Only two things enter my mind -- perhaps your diffuser is sucking down for some reason and dragging on the ground, or your chassis is sitting too low. Probably noone has the answer and you will need to diagnose this at the track.
A friend of mine was having lots of porpoising issues (lots of vibration at high speed) with his front diffuser (SR3). He tried everything except a new diffuser, and it was giving him fits. The Radical technicians and dealer technicians had ideas, but noone could determine why this was happening. Finally, he replaced the diffuser with a new one and that fixed the problem. I can get more details from him if you want. I think it may have been mounted improperly and that there was too much play among the zeus fasteners. Something like that.
