The CPR6 manifold is manufactured from high-quality automotive-grade cast alloy and is designed to deliver significantly better breathing and airflow compared to the stock manifold. It provides the Alloytec V6 with a smoother, cleaner intake path, resulting in power gains of up to 11%. While there may be a slight reduction in low-end power, the CPR6 offers noticeably improved performance at higher RPMs, allowing the engine to breathe far more efficiently.

Our manifold insulators and plenum spacers are manufactured from a high-quality, heat-resistant thermal composite plastic. This material is specifically designed to reduce heat transfer, improving intake air temperature and overall performance. Unlike some alternatives, they are not made from wood and are backed by our lifetime warranty for peace of mind.

The main difference between the manifold insulator thicknesses is the level of torque increase they provide: 6.35mm – around

10% more low-end torque, 12mm – around

13% more low-end torque, 25mm – around

15% more low-end torque across a broader range.

The 25mm option delivers the greatest improvement in low-end torque by effectively increasing the runner length. However, before selecting a thickness, we always recommend measuring the available clearance under your bonnet to ensure a proper fit.

Yes, we recommend pairing a 12mm manifold insulator with a 25mm plenum spacer mainly for packaging reasons, as this combination typically clears the bonnet without modification. Ideally, the best setup would be a 25mm manifold insulator and a 25mm plenum spacer for maximum gains. However, this would generally require reworking the bonnet reinforcement to provide adequate clearance.

Manifold insulators themselves replace the factory gaskets pair of 25mm manifold insulators, longer manifold bolts, and gasket sealer

Unfortunately, we no longer sell the bolt packs separately. This is due to the number of counterfeit insulator kits on the market. To ensure proper fitment and reliability, bolts are only supplied as part of our genuine MACE kits.

We don't unfortunately.

Unfortunately, this is not something that we offer at this point in time.

If your factory gaskets are still in good condition, they can be reused. However, to ensure proper fitment, all MACE Manifold Insulator and Plenum Spacer kits include gasket sealer, so the use of factory gaskets is not required.

Discoloration of the manifold insulator itself is not a problem and won’t affect its performance. However, if it appears to be soaked in oil, it may point to an underlying issue such as a PCV (Positive Crankcase Ventilation) system fault or a related engine condition. We recommend inspecting the PCV system and associated components to rule out any oil-related issues.

The main difference lies in the PCV (Positive Crankcase Ventilation) layout, which varies from model to model. Because of this variation, the manifold insulators are designed specifically to match the PCV configuration of each engine series.

The difference in thickness mainly affects torque output and manifold cooling. In general, the thicker the insulator, the greater the torque gains in the low- to mid-RPM range, as well as improved heat shielding to keep the intake manifold cooler. This results in better efficiency and stronger performance where it’s most noticeable in everyday driving.

Yes, you can use both, but whether it’s the best option depends on your application and driving style. If you had to choose just one, we generally recommend the lower manifold insulator first, as it usually provides the most noticeable gains. That said, you’ll see benefits from either upgrade, and using both together can further enhance performance if installation space isn’t an issue.

There is about 3-4% difference in down low torque.

We don't unfortunately, our manifold insulators only suit the Boss variant.

With the exception of the 4 M6 screws, all of the hardware that we supply in the bolt packs of our kits need to be custom made to be able to install the insulator.

They are.

MI603, MI631 or MI635 would all be suitable to for your vehicle. For maximum torque gains, I would recommend our 25mm manifold insulator, MI631, otherwise, if your budget does not stretch far enough, then the other insulators would still work well as advertised.

If you are referring to the 2 orange strips with the black stripe that sit at the front and rear of the lifter valley, then yes. These can be noted in the image in the link below:
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Results can vary depending on your vehicle and driving style. On average, you can expect around a 3% improvement in fuel economy and approximately a 5% increase in low-end torque, giving you better throttle response and overall drivability.

The profile between the two insulators in these kits is different to take into account the different PCV port designs for each inlet manifold type. To clarify which insulator fits which engine, MI601 is suitable for VS-VT Commodore Ecotec engines while MI602 is suitable for VX - VY Commodore Ecotec engines.

Yes, it will.

Given its thermal resistive properties, the plenum doesn't need to be HPC coated. The profile of the insulator is designed to suit the stock intake runners.

Ideally, you'd want a 12MM manifold insulator with the 12MM plenum spacer for the most gains. We recommend taking a couple of measurements under the bonnet beforehand though for clearance purposes.

Yes, you can paint your manifold insulator any color, however we do recommend that it be prepared prior to painting. This includes sanding, priming and the use of high temperature paint.

With the 6mm and 12mm items not so much, with the 25mm item, you may see small drop off in peak power depending on other mods. However, in our opinion, you more than make up for it with the low/mid range gains in torque/power, considering it's a street vehicle.

Forced induction turbocharger supercharger

Unfortunately, no. Because of the M90 supercharger setup, the engine doesn’t use a traditional plenum, so a plenum spacer cannot be fitted. However, we do offer manifold insulators designed specifically to suit M90 supercharged applications.

The main difference is in the level of torque improvement. A 12mm manifold insulator provides around a 10% increase in low-end torque, while the 25mm version delivers closer to a 13% gain over a broader RPM range. The thicker insulator also offers better heat resistance, helping to keep intake temperatures lower for longer.

Ideally, the two items combined will provide maximum power gains but if we had to choose one item we would definitely recommend the cams for the following reasons:

These items can be used on dead stock engines right through to dedicated race engines.

If you want it to take off quicker then a set of manifold insulators, higher diff gear ratio, air intake upgrade and tune would certainly help out.

That's part of the crank case ventilation. The problem with it being cracked is not so much due to the crankcase ventilation, but the fact that it will cause a vacuum leak in the manifold. This results in a poor idle quality and possibly decreased throttle response.

If you want it to take off quicker then a set of manifold insulators, higher diff gear ratio, air intake upgrade and tune would certainly help out. Our cams are more beneficial mid to top end.

Yes it does

No tuning is required for this mod. Bonnet clearance is rarely an issue but can be resolved by removing the engine cover if required.

Yes, they do. The Colorado V6 uses the same bolt and port profile as the Commodore engines, so the MACE manifold insulators will fit.

Please ensure you have removed the 4 middle bolts which are hidden by the plastic cover. This plastic cover must first be removed in order to expose the hidden bolts.

We've sold many over the years and we have never had any bad feedback. Most customers report cooler manifolds and a slight power increase due to the improved air distribution into the heads.

No, we strongly recommend for sealant to be used in all applications.

For N/A (naturally aspirated) applications we recommend the 25mm manifold spacer and 12mm plenum spacer.

If you are running boost we recommend a 25mm plenum spacer and 12mm manifold spacer, as the thicker plenum spacer does offer even better air distribution between cylinders, which is more critical in boosted cars making lots of HP.

Yes, the insulator can be purchased separately.

Ideally you would port match the insulator to suit the heads and intake manifold due to manufacturing variances.

Generally with just a single 12mm spacer fitted the engine cover will fit fine. We recommend that you measure the current clearance without the spacer fitted to see how much clearance you have under your strut brace. Please bear in mind that you also need sufficient clearance to allow for torquing of the motor as it tilts during acceleration and can rub up against your strut brace or bonnet. We also recommend customers to remove the engine cover as it traps heat like an insulator which isn't ideal.

Bonnet clearance won't be an issue with raising the blower by 25mm.

You need to use the factory inlet manifold gaskets in between the inlet manifold and insulator. You need to use sealant between the insulator and heads.

If installed with the supplied silicone sealant, then gaskets are not required.

2-Raising manifold by 25mm: Cover will need to be trimmed around the alternator or bonnet liner needs to be removed or trimmed. Otherwise cover will rub on bonnet liner

3-Raising manifold by 37mm: Cover will need to be removed. Otherwise cover will rub on bonnet liner/possibly not close depending engine mounts

4-Raising manifold by 50mm: Will require bonnet mods without cover

Silicone dries in 1 hour, and fully cure in 24 hours. Your can can be driven after one hour of installation or 4-5 hours in supercharged or turbocharged applications. Allow more time in cold or very dry conditions. Please ensure you refer to instructions on the back of silicone packaging.

If installed correctly, they will seal perfectly. They seal so reliably that we offer a lifetime warranty on this product, assuming no major backfires occur.

You can complete the installation using Allen keys, a socket set, a screwdriver, and pliers. We also recommend using engine degreaser to clean the intake manifold, especially around the injectors in the lower intake manifold. This ensures that no dirt falls in when the injectors are lifted out as you remove the plenum.

Once all bolts are removed, the manifold can be lifted off without damaging the insulators. However, be careful not to bend the manifold insulator during removal, as excessive bending may cause it to break.

Before reinstalling the manifold, ensure that all mating surfaces, including the manifold insulator, are cleaned of any residual silicone using a scraper. Apply fresh sealant to all surfaces. The installation process is the same as when the insulator was fitted initially.

With the 6mm and 12mm items, there is little to no effect. With the 25mm item, you may notice a small drop in peak power, depending on other modifications.

However, the gains in low- and mid-range power typically outweigh any small loss in peak power, especially for street-driven vehicles.

If you want it to take off quicker then a set of manifold insulators, higher diff gear ratio, air intake upgrade and tune would certainly help out.