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Was waiting for someone to develop this kit. Always something I thought of when I saw guys do aftermarket exhausts without the aero-designed muffler of the stock GT4. Must make the diffuser much more efficient than OEM
Interesting! I actually also was curious about this when looking at aftermarket exhausts
The few questions I'd have are:
How much more rear downforce are we taking? Enough to need to adjust front aero? If no - then is it even worth it?
Or another way of asking the same question - how much rear aero is lost by removing the OEM cans and replacing with aftermarket? Again, worth the effort? They state on the web site that "state-of-the-art analysis software" was used - so sounds like no wind tunnel studies were done.
Wonder how much heat gets trapped in there now with the exhaust not having airflow? This would be my biggest concern. OEM design could have easily done full coverage (covering the exhaust) but they didn't (assuming due to heat?)
If you look at the OEM exhaust cans, they are slightly ribbed/profiled for laminar flow… so when there is a void with a smaller aftermarket system, you are potentially losing df and certainly increasing drag effect.
So look at this as regaining aerodynamic performance.
I was going to fabricate myself something but this kit looks perfect. I would get one for sure but shipping to Aus costs almost as much as the thing itself!
Does it fit the 4RS? As already noted, this could be worthwhile for those with aftermarket mufflers.....
Same question for the Spyder RS. I can't stomach the shipping costs of 1, but if me and a few mates do a group buy we might be ok with splitting shipping costs up.
I was going to fabricate myself something but this kit looks perfect. I would get one for sure but shipping to Aus costs almost as much as the thing itself!
Had this come up 10 days ago, I could've brought a set over from the States. I came down to Sydney to see my folks last week!
Keen to hear thoughts on how it works out and also holds up against gravel etc. from the road.
Just wanted to share my feedback about this kit. I bought this as soon it was released and was eager to install and run it on my last track day of the season at Leguna Seca.
Installation: Much tougher than the video and the write up made it out to be. I currently run the 4RS rear bumper side diffusers and I believe this was the reason why the installation much more difficult than anticipated. I had to remove the center diffuser piece and loosen everything to get these panels to fit perfectly. Having said that, it is 100% possible to fit these on a 4RS. With some slight modifications to the original design, I believe Verus would be able to make this an easier install for the 4RS.
Fitment: Panel fitment was near perfect. I run a Kline OAP and backbox and can confirm the panels cleared everything. Again, I felt like running the 4RS rear bumper side diffusers made the fitment tolerance much tighter.
Performance: Disclaimer - I’m not an aerodynamicist, just an enthusiast that enjoys HDPE / track days. I currently run my GT4 with full 4RS underbody aero and an increased/modified AOA on my rear wing. With the diffuser panels installed, I noticed a tangible difference on track and experienced a slight increase in understeer. The product does exactly what it’s advertised to do. Verus even suggests to run the diffuser panels in conjunction with their front dive planes to achieve F/R balance. In regards to heat, I too was apprehensive about the possibility of trapping more heat in the area. Happy to report that I did not see any significant difference but keep in mind that I was running in that cool 65* California weather. FWIW, Verus Engineering confirmed that they have not experience any overheating issues with their GT4 test car.
Durability: Due to Leguna Seca’s elevation changes and compression corners, I did find the panels’ strakes to hit the track surface numerous times. During my post track inspection, I found the strakes on both panels were bent outward and the material slightly shaved off due to the repeat impact. Since the panels are made from aluminum, it was an easy fix to just bend them back to the original angle.
In conclusion, it’s a well made piece of kit as expected from Verus Engineering. I hope the panels continue to hold up to more track days next season. The aero impact isn’t mind blowing but enough to me that I’ll be looking to balance it out with some changes to the front end shortly. Hope this helps everyone!
12-16-2023, 07:52 PM
Verus Engineering Rear Diffuser Panel Kit
