How to Install a C8 Corvette Rear Diffuser (Verus Step by Step)

A rear diffuser is one of the few C8 aero parts you can bolt on in a driveway in an afternoon. This guide walks through the Verus Engineering kit for the Stingray using Verus’s own install manual (Rev 01, dated August 19, 2025), then covers what changes if you buy the carbon version or another brand.

What the Verus rear diffuser is, and what Verus says it does

The Verus Engineering rear diffuser for the C8 Stingray is a sheet aluminum underbody piece that takes the place of the two factory splash shields under the transaxle. It is made from 5052 aluminum, laser cut and press-brake bent, powder coated black, with stainless hardware. It goes on as a main plate, two side plates and two bolt-on strakes.

These are the maker’s claims, not mine. Verus says the diffuser adds downforce and cuts drag compared with a stock Stingray, and improves the lift-to-drag ratio. Verus says it designed the part from its own scan of the car, ran it in OpenFOAM CFD, and then checked it with real-world testing. Verus also calls it the base piece of its Ventus aero kits, built to balance front aero like a splitter and dive planes.

What Verus does not publish today is a downforce number for the diffuser alone. Its product page has none, and its Ventus packet (dated January 22, 2026) gives no standalone figure either. The number most people quote comes from the retailer. Paragon Performance lists 20 lb (9 kg) of added downforce at 80 mph and 29 lb (13 kg) at 100 mph. I found no independent test of either figure.

Which C8s it fits: Stingray only, as listed

Verus lists part A0291A for the “Corvette Stingray (C8)” and gives no model years. Paragon’s listing for the same part number is more specific: 2020 to 2026 Stingray, coupe and hardtop convertible (HTC). Nothing I read lists it for a wide body car.

Verus’s manual has no separate steps for Z51 and non-Z51 cars. If you have a 2027 Stingray or any wide body car, including a Z06, ask Verus before you order.

Exhaust matters too, because the diffuser hangs from the exhaust hanger bolts. Paragon says the kit works with the stock exhaust and with aftermarket systems that stay inside the factory exhaust space, and that anything outside that space needs modification. If you are still choosing a system, my Fabspeed vs Soul Performance exhaust comparison is the place to start.

What is in the box

This is the parts list from Verus’s install manual. The kit ships with both stainless and black oxide fasteners for the visible spots, so you pick the look.

You also reuse factory parts: 11 of the original 7mm-head splash shield screws and two clip-on nuts from the first shield you remove.

Tools you need

• Jack and jack stands, or a lift
• Ratchet or impact
• 7mm socket (factory splash shield screws)
• 13mm socket (exhaust hanger bolts)
• T15 Torx bit
• 4mm Allen key or socket (the M6 button heads), plus a 2.5mm Allen, which Verus also lists
• Trim tool or clip remover for the plastic push clips

Step by step: installing the Verus rear diffuser

These 12 steps follow Verus’s install manual for the sheet metal diffuser, in my words. Keep the manual open next to you for the photos.

1. Raise the rear and support it. Jack and stands or a lift. Find the rear splash shields under the transaxle.
2. Remove the first splash shield. It is held by 11 screws with 7mm heads and 1 plastic push clip. Keep this shield nearby. You need two of its clip-on nuts later.
3. Remove the full-width shield. That is 6 more 7mm screws, 4 T15 screws and 2 push clips. Neither factory shield goes back on, so store them.
4. Fit the driver’s side bracket. Find the exhaust hanger inside the exhaust tip, as the manual shows. Remove its two 13mm bolts, slide the Verus inner bracket between the body and the hanger, and thread the bolts back in loosely.
5. Repeat on the passenger side. Only after the driver’s side bolts are back in. Leave all four bolts loose for now.
6. Move the clip-on nuts. Lift the tab on each of the two front clip-on nuts in the shield you saved and push them out. Clip them onto the engine splash shield at the spots the manual marks, threaded side up.
7. Test fit the main plate. Hold it up with the center 7mm screw and the two front 7mm screws. Shift the brackets until the holes line up. Then take the plate back off and fully tighten all four exhaust hanger bolts.
8. Hang the main plate for real. Use 11 factory 7mm screws plus 4 M6 button-head screws with washers. Put the serrated nuts on the back of the M6 screws finger tight. Leave everything loose.
9. Prep the side plates. M6 clip-on nuts go in the larger oval holes, M4 clip-on nuts in the smaller round holes, threaded side up on both.
10. Seat the side plates. Angle each one up into the bumper and push upward until it sits flush and flat against the fender liner. The plate flexes a little. Go slowly here. Then loosely add two M6 x 16mm screws at the front and one M4 x 16mm screw at the rear of each plate.
11. Add the strakes. One strake goes between the main plate and each side plate. An M6 x 16mm screw, washer and serrated nut clamp the three layers. Use the slots to match the height and angle of the strakes riveted to the main plate.
12. Tighten in order, then lower the car. Check that every section lines up with the car and with each other. Tighten the strakes, then the main plate, then the M4 side plate screws, then the M6 side plate screws.

One tip from the manual is worth repeating. Verus suggests running the M6 button heads in with an impact and a 4mm Allen socket. The serrated nuts bite on their own that way, so you do not need a wrench on the back side.

How long it takes and what it costs

Verus’s manual says 2 to 2.5 hours and rates the difficulty moderate. Paragon’s listing says 3.0 hours. Plan on an afternoon the first time.

Verus lists the aluminum kit at $879.95 as of October 10, 2026. When this post first went up in July 2021, it showed the kit at $749.99 at Paragon. The carbon version (part A0422A) is $2,299.95 at Verus, which is $1,420 more.

The mistakes that cost you time

• Pulling both exhaust hangers at once. The exhaust needs one hanger holding it the whole time.
• Putting the first shield away too early. Two of its clip-on nuts move to the engine splash shield. Pull them before the shield goes on a shelf.
• Tightening the hanger bolts before the test fit. The brackets need to float until the main plate holes line up.
• Clip-on nuts facing the wrong way. Threaded side goes up, on the shield and on both side plates.
• Forcing a side plate into the bumper. The manual warns the bumper can be damaged at that corner. Angle it in, then push up.
• Tightening as you go. Everything stays loose until all the sections line up. Then tighten in the order in step 12.
• Not checking your exhaust first. A system that sits outside the factory exhaust space needs modification, per Paragon.

What the Paragon Performance install video shows

This is Paragon Performance’s install video for the same Verus kit, and it is the one Paragon still embeds on its A0291A listing. Going by its chapter list, it covers tools at 0:29, then the rear wheels come off at 1:04 and the mud flaps at 1:24. The panels come down at 2:02. The brackets go on at 3:28 and the diffuser at 4:31. Side panel hardware starts at 7:34, the side panels at 8:34 and the strakes at 8:52. The mud flaps go back on at 10:08.

One difference to know about. The video takes the rear wheels and mud flaps off. Verus’s current written manual lists neither step. My read is that the extra room at the corners helps when you seat the side plates, so if a side plate fights you, that is worth trying.

Installing a different brand of C8 rear diffuser

The Verus aluminum kit is one way to do it. Two other published install procedures show how much the job changes from part to part.

Whatever brand you buy, answer these before the car goes up in the air:

• Where does it mount? Exhaust hanger bolts, factory shield screws, or new holes.
• Does it need drilling, and where? Verus says none on the car. ACS says four holes in the undercarriage pan.
• Does it clear your exhaust? Paragon and ACS both flag aftermarket systems.
• Which factory panels come off for good? Bag and label them so the car can go back to stock.
• Is it listed for your car? Everything in this guide is listed for the Stingray.

If the diffuser is going on because the car is headed to a road course, read how to prepare a C8 Corvette for the track first. The prep list matters more than the aero.

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