So after more then a decade of working on and building Hondas, favoring H series and Js, I have accumulated an assortment of rare parts and detailed knowledge on various H/F series motors. One thing that has eluded me is the H22A7, parts and knowledge of it as little is known about them, plus less where made then all other H variants including the Euro R and Type S. It is rated between 209hp-212hp and 157-168tq depending on who you ask and where you read. Locally in 2008 one was dynoed here on a fully stock ATR ecu, regular h22 header and 2.5" all the way back I think. If I remember correctly the guy made 190ish whp and 160ish tq which I thought was impressive because the only other type s/ euro r setups I knew of back then only pulled 170 or so at the wheels here on stock ecu setups. We are at 5500ft above sea level. Damian was his name I think? Had an ITR as well, lived in ABQ NM if anyone on this forum knows him. Regardless his setup caught my attention so over the last 3 years I have attempted to acquire parts and data from the elusive h22a7, and today I shall begin documenting for people like myself looking to no avail for data on the matter of what really sets it apart from the other J spec H type S / Euro R power houses.

First we will talk about the block, the H22A7 was FRM just as all the great H series where, but casting is much cleaner then the rest, and it's head was PDE, as well as rods. Pistons where PDEE, euro r? Not sure on that, I've been told the compression height is different so this is unconfirmed. It had the factory Honda P&P treatment and the better valve angle of course, but from what I have concluded the cams are different then the S or Euro R, as well as the C/r setting in the 10.8:1 range from what I've been told. I have found a head for sale and will be measuring the actual specs of the cams as soon as they are in my hands, then I will update this post with those numbers.

The A7 intake manifold is basically a Euro R setup, slight variations in the casting though. The ATR manifold appears smoother then the already clean euro r units and utilizes H23A blue top sized throttle body. These things alone really aren't that special but something really unique and highly under rated about the A7 is the beautifully designed exhaust manifold. The A7 header is a very detailed piece, with no stock heat shields, and extreamly well made smooth large tubes that are significantly larger then the other H headers. All other OEM H headers actually bottle neck right as the exhaust exits the head into them. They also utilize expansion chambers at the "y" parts which not only helps flow and velocity but also improves scavenging effects significantly. So basically the H22A7 header is a must have for any stock Honda parts only H build and few people know it. I also have an A7 header on the way and pictures will be coming to this thread soon for those who haven't seen one.

The ECU is likely also different from euro r units and I'll update once I find out more info or buy one from my contact in Ireland. The ATR tranny is a U2Q7 LSD with the shortest gears as a whole of any LSD H trans other then maybe the hyper rare P2T4 LSD which was only found in the JDM Accord SIR in the early to mid 90s and was not standard, it was a factory special order option. There is however a non LSD p2t4 varint for the standard off the show room floor accord sir h22a model.

So far that's all I have, until I have a whole stock ATR in front of me I won't know all the details but anyway, I hope this has been helpful and stay posted for updates! Please add info if you own a A7, don't add info if you have only read about them please so we can finally get the true specs on this unique H variant. Hope everyone is having an awesome day!

Above shown is the A7 manifold as promised, I’ll be adding more pictures and explaining more about the design as well as functionality of the expansion chambers at the top Y sections on this new thread made specifically for the A7 exhaust manifold: https://honda-tech.com/forums/all-mo...eader-3325128/ I will have comparison pics of various manifolds side by side and dyno charts in time.