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A forum member has sent us his stock Primary/Secondary catalyst section for patterning. We will be jigging & manufacturing a catalyst section for the XJ X351 cars which should make a nice little bump in HP. On a 5.0SC engine, I'd expect to see something like 20-25BHP based on dyno data we have generated from other engines of similar output & displacement.
It's also going to give a nice growl, can't wait to hear a sound clip when they go on the car.
Quick update. The finished parts should be delivered to the installing shop today. Hoping to have confirmation of fitment and some video clips soon.
Based on the size & output of the engine, we are expecting around a 20-25BHP bump from the 5.0L SC.
Also based on some experience with other 5.0 & 3.0L applications I can say that these will fit the non-SC 5.0L cars, and will most likely fit the 3.0L cars as well.
I would expect the non-SC to net something IRO 15-20BHP. We see a range of 15-18BHP dyno-tested, on the 4.3 & 4.7L Aston Engines which are making 380-430BHP depending upon the spec. Results on a similar displacement & output engine should be roughly similar.
Replacing ceramic 2x 600 cell primary cats and 2 x 400 cell secondary cats with a pair of 200 cell motorsport metal cats will always yield power, and you'll get a nice aggressive note to the exhaust at the same time.
Soon as we have sign off here, I will probably launch a group buy/pre-buy special and we will crank a few sets off!
I'd be very interested in a group buy. Can't wait to find out more!
Okay, sounds good to me! Good news is the parts are on the car and Johncy says it sounds great. I want to talk to the installer and confirm a couple of things and then we will launch something
What is the life expectancy of the Velocity 200 cell cats, in years and miles, compared to the OEM cats?
What is VelocityAP Industries Ltd.'s warranty on those cats?
Typically we expect to see greater life expectancy from a metal-matrix motorsport type catalyst than a ceramic OEM-type catalyst. Metallic types have higher thermal conductivity than ceramic, which guarantees more uniform temperature distribution. This gives better prevention against 'hot spots', or areas where the catalyst matrix starts to melt & break down, resulting in blockage or total deterioration of the catalyst brick.
I can't give you a years & miles measurement versus the OEM cats, whatever I told you would be off the top of my head, but the important thing is the use of high quality metallic substrate at 20g/ft3 loading will provide a very durable catalyst.
We warranty our catalysts as with all our exhaust products for 25 years against workmanship and corrosion. The catalyst brick itself is not something that we explicitly warranty, as the durability of the catalyst will be greatly affected by the condition of the car and engine. For example, a poorly running car can quickly destroy a catalyst if an injector is burnt out as EGT's will climb rapidly. Or a car which is badly tuned could similarly be running far too lean a mixture and destroy a catalyst.
Having said that, we stand behind the products 100% and if someone experienced a premature failure of a catalyst we would replace it no questions asked. That has always been our policy, but in 8 years of selling sport catalysts for exotic cars we have never had to replace any due to failure.
I just to thank Stuart over at Velocity AP for being there throughout the whole process from start to finish. I sent out my stock cats to be measured and scanned and a week later, the car has new high flow cats. Fitment took some time because of the bottleneck style flange. It had to be perfectly aligned in order to be fully sealed. When we first started it up, I was taken back by the rumble upon cold start.
This car feels like a completely different animal now! Give it a couple hundred more miles and the ECU should fully adapt to the modification. The car feels healthier than it has ever been.
I will be dynoing the car again soon to see how much the gains were. Last time I dynoed, I put down 507whp (Dynojet). Cant wait.
The sound upon acceleration is indescribable. It is very docile at cruising speeds but as you hang the revs, the volume increases. The note is glorious. Backfire is on demand right after you let off the throttle. Almost everytime, it pops and backfires.
Shot out to Stuart and Velocity AP for great service and craftsmanship! I highly recommend this product because the stock catalysts are 600 cell and these are heavy loaded 200 cell cats. You are achieving way better flow for a boosted car.
Awesome stuff Johncy. Thanks for being a great partner and helping bring these to fruition. Can't wait to hear this beast, it must scare the crap out o of people!
VelocityAP 200 Cell Sport Catalysts for XJ X351
