The "J" Swap

In my opinion J32A2 is a better choice in my opinion due to it's shorter stroke. With some cheap head modifications (few hundred dollars) you can get them to reliably rev to 7400-7500RPM but to be honest you can see from our racecar dyno sheet that torque drops off sharply after 7000rpm or even a little before.



The J35A3 restricts redline by about 700RPM and doesn't really give you much extra torque for the lack of RPM and has a lower HP figure. There are other J35 engines that make good HP and torque but their blocks aren't as strong etc so have other downsides...... some might like the extra torque but I think overall the J32 is a better choice since it's a closer fit to the original C30. The J35A3 has a slightly lower compression ratio (10:1 vs 10.5:1) so lends itself to an easier tune with boost, but it's pretty negligible.

J32A2 - 260HP @ 6100RPM and 232lb/ft @ 3500RPM
J35A3 - 240HP @ 5300RPM and 245lb/ft @ 3000RPM

Hope that's of help to those trying to decide.
 
SOOOOO when will you have a group buy for the mounts and custom parts required for this swap. I think I speak for everyone here that price is not really an issue so much as just being able to get the parts and install one of our own. I would have to say the J35A3 froma TL with 290hp would have to be my route if i did the swap. I still want to try and build my C30A for high RPMS but a J35A3 would definitely be cheaper to build and replace parts for later on. What you should look into after you have the swap kit selling is see about a exhaust shop that can make stainless exhausts to fit with the different engines. That would be a good market for you to get into considering it will be all custom for everyone installing a J series in their car.
 
I don't know the exact rules around selling stuff on here, but I'd imagine the mods might have taken them down since you're essentially selling items............ they probably want you to become some kind of reseller to "trade" on here........ just a guess.

I have looked all over for the "rules" and could not find them. I have seen lists created outside of the vendor section or marketplace in other sections of this site, so that led me to believe it would be okay to do so here.

I probably wasn't clear enough in my post that this was not a listing to sell anything, I was just trying to gauge interest to help me decide whether or not to produce the product and become a vendor. The people following this thread may not even look in the vendor section.

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From what pm i got they want you to post in vendor section

You got a PM? I was the OP and I never got notified, I even sent an email asking for help and guidance as to where to post the list.
 
Yeah mate, I totally agree with you............... it's a real grey area when you don't have anything to sell but want to gauge interest.............. I don't think there was anything wrong with what you were doing personally........... I guess they just get a few people taking the piss with that kind of stuff so crack down........
 
Thanks f1racr and Nick675. Nick675, I got your PM, thanks. So, I will chalk this up to misdirected communication and move on.

As for the car, I did get all of the auto tranny codes cleared and the check engine light is off! I think the speedometer and 5000 rpm rev limit are related to the speed sensor, so that is next on my list.
 
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would you be offering an plug and play electrical harness as well? something that would allow swappers to go back to OEM if needed
 
Would the J35A3 be the same swap in as your J32A3?

Yes, the J35A3 is basically the same swap as the J32A2. In fact I plan on picking up a J35A3 next.

The J32A2 and J35A3 are all but identical except for the longer stroke in the J35A3.

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would you be offering an plug and play electrical harness as well? something that would allow swappers to go back to OEM if needed

As mentioned in a previous post, yes I may offer to sell other parts necessary to make this swap possible for others.

When the time comes, I will create a post in the Vendor section to find out what people might be interested in. Basic motor mount kit, exhaust adapters, electrical harness adapter, etc.

So far my swap is plug and play and I can go back to all OEM with the C30 at any time with no trace of a swap. Except on this thread of course.
 
Well even though i have my C30 still i would be interested in a kit even if i dont swap to it for good while. Never know when you will need a new engine and C30 are getting harder to come by.
 
From what I read on the forums the J35a3 is tuned down from factory compared to j32a2. My guess is Honda was looking for more torque and less peak power to push around these SUV's. Ive seen these motors make close to 300whp on most swaps with just aem ems and headers/exhaust. Seems the weak link in these j series motors are the valve springs and retainers, they dont like to be revved past the stock limit. Aftermarket springs/retainers are a must if looking to rev higher. What mods did this j32 racecar have? nice numbers


In my opinion J32A2 is a better choice in my opinion due to it's shorter stroke. With some cheap head modifications (few hundred dollars) you can get them to reliably rev to 7400-7500RPM but to be honest you can see from our racecar dyno sheet that torque drops off sharply after 7000rpm or even a little before.



The J35A3 restricts redline by about 700RPM and doesn't really give you much extra torque for the lack of RPM and has a lower HP figure. There are other J35 engines that make good HP and torque but their blocks aren't as strong etc so have other downsides...... some might like the extra torque but I think overall the J32 is a better choice since it's a closer fit to the original C30. The J35A3 has a slightly lower compression ratio (10:1 vs 10.5:1) so lends itself to an easier tune with boost, but it's pretty negligible.

J32A2 - 260HP @ 6100RPM and 232lb/ft @ 3500RPM
J35A3 - 240HP @ 5300RPM and 245lb/ft @ 3000RPM

Hope that's of help to those trying to decide.
 
Yeah I kinda agree you would expect that the J35A3 should have less top end power and more torque but it really doesn't based on the official numbers but saying that, it's got a little bit more, but more importantly it's 500RPM lower down, but I wouldn't say for a sports car project that the extra piston speed of the 3.5 weighs up against the extra low down torque, but then again everyone's different right so might prefer the 3.5.

J32A2 - 260HP @ 6100RPM and 232lb/ft @ 3500RPM
J35A3 - 240HP @ 5300RPM and 245lb/ft @ 3000RPM

You're right on the valve springs with the J series, but there's a J series which has totally OEM internals apart from valve springs and retainers ($ 200 worth) and its making 700HP at the wheels ! No idea how long it will last, but the guys been drag racing it for half a season at least........ no idea what it would be like on the track.......!

Our race car doesn't have any internal modifications, just got some aftermarket exhaust manifolds (actually didn't make any difference what so ever to the dyno curve though) and a custom air intake we made....... that's it....
 
I will use the J32A2 stock, albeit it has a freer breathing intake and exhaust and I polished the fuel injector runners a bit. Since the J32A2 and J35A3 share the same block (11000-PGE-810) and head castings (front head 12100-P8E-306, rear head 12300-P8E-306) when I pick up a J35A3 I plan on removing the intake manifold spacer and running it with the J32A2 (Type-S) ECU and cams and installing valve springs and retainers that can handle higher revs. I plan to have turbo manifolds built that will fit either engine and allow me to run twin turbo. I am also brainstorming a twin or triple throttle body setup. I have seen some other twin throttle body setups for the J-series. I will try and get baseline dyno runs done along the way for comparison.

I have the speedometer working from the stock speed sensor in the NSX transmission and the coolant temperature gauge working by installing the stock NSX coolant temperature sending unit. There is actually a boss on the J32A2 coolant crossover manifold and earlier J-motors have the exact same coolant temperature sending unit installed in that very location, so I just drilled and tapped it for the sender (1/8” NPT).

Remove the C30 coolant gauge sending unit from here.
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Drill and tap the J32A2 here.
20140819_131313_zpsc84da13f.jpg


Install the C30 coolant gauge sending unit.
20140827_123628_zpsd7175651.jpg
 
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I REALLY hope you will be at NSXPO to show this accomplishment off
 
I REALLY hope you will be at NSXPO to show this accomplishment off

Unfortunately, I will not be able to make it to NSXPO this year, but I hope to make it some day.

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The video kept cutting out, so I will have to make another one.

Here is a picture for now.
20140901_121507_zps2a459a85.jpg
 
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