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    Revisiting the V6 swap

    I have finally decided to turn the CB7 into a track-only car. Sometime in the near future, I will finally be making a MR thread, but for now I'm delving into the potential swap options. With a goal of 300WHP NA, my options are limited. K24 would be fairly easy to swap in, with 2 different sources for mounts and axles. However, $10k just on the engine is far too pricey for me. Having swapped to a '03 TL and now a '00 Nissan Maxima as my daily, the torque of a V6 is way too appealing to ignore. Therefore, the CB7 will be getting a V6.

    Issue 1: there's no good documented swap for a V6 of any kind in a CB7. That means axles, mounts, wiring, and hood clearance all have to be figured out. This does open up engine options, however.

    Issue 2: weight. The CB7 already does not have great weight balance, and is only made worse when you strip the interior, sound deadening, and every other item besides glass to reduce weight. An H22 is not the lightest of I4's, but a V6 is going to be heavy no matter what. Reducing under-the-hood weight as much as possible must be done.

    Issue 3: availability. All things considered, a FWD V6 with a manual is not super common, especially if they make good power.

    At this point, I've decided that I don't need to stick to Honda engines, especially since mounts, axles, and wiring will be custom no matter what, so it'll be the same amount of work for a J32a2 as it will for a VQ35DE.

    I'm going to document everything I do and research here, since I want by the end of this a good guide for swapping a V6 into a CB7. If anyone here has done a V6 swap into a CB7, every bit of information you can provide will be invaluable.

    Now for the research...

    Engine Choices:

    J32a2

    Weight over a H22A: ~70lbs, could be less with AC, PS removal and change in headers/intake

    Stock HP: 260HP

    What to do to hit 300HP NA:
    J37 crank, '05 RL rods and pistons, tuning

    Transmission Options:
    6SPD from 7th Gen Accord, 4th Gen TL Base, or 2nd Gen CL

    Issues: SOHC, although may not actually be an issue based on my research for my power goal. Aftermarket is not great, but it seems I need only OEM parts for the huge power gains. Likely going to have to replace the chassis harness, but I don't need much in a racecar so this may not be a huge issue.


    VQ35DE

    Weight over a H22A: Unsure, what info I found so far puts it at ~500 lbs total so not very significantly more than the H22

    Stock HP: 255HP ('02-'03 Nissan Maxima, the likely source of this choice)

    What to do to hit 300HP NA:
    Depressingly, too much. Intake, exhaust, cams, good tune, usually still needs internals.

    Transmission Options:
    5spd or 6spd from 00' to 03' Maxima, 6spd from 3.5 Altima '02 and up, Sentra Spec V 6spd and Maxima bellhousing

    Issues: DBW, not DBC. Means I need to swap pedals. Will likely have to replace entire chassis harness to use it, including all parts. That said, I don't need much in a racecar so this may not be a huge issue.


    J35Ax

    Weight over a H22A: ~70lbs, could be less with AC, PS removal and change in headers/intake

    Stock HP: 248HP (Acura MDX)

    What to do to hit 300HP NA:
    J37 crank, '05 RL rods and pistons, tuning, probably...

    Transmission Options:
    6SPD from 7th Gen Accord, 4th Gen TL Base, or 2nd Gen CL

    Issues: SOHC, although may not actually be an issue based on my research for my power goal. Aftermarket is not great, but it seems I need only OEM parts for the huge power gains. Likely going to have to replace the chassis harness, but I don't need much in a racecar so this may not be a huge issue. Engine differs slightly from the J32a2 specifically in the cylinder linings, so this may not be an option.

    Current Choice: J32a2


    Mounting, wiring and axles:

    There are a few chassis with V6 swap mounts that are very similar to the CB7, specifically the BB6 aka 5th gen Prelude. The innovative mounts look like they could be modified to fit, but I'm curious about the chassis rail spacing since that might mean a different kit would work better, like for a Civic.

    Wiring is the easiest part. I can either just take the whole harness from a TL/CL and strip what I don't need and add what I do, or just build a new harness. I've never found wiring to be hard, so I'm not worried about this part.

    Axles may be the hardest, or easiest. A lot of the CB7 front end is the basis for the TL front end, so it could be possible to just swap over most of the TL front end and use the stock axles. Unfortunately, there's not a lot of good images online of this, so more research is needed. I could get custom axles made too, but I'm not sure where is good now.

    Resources, threads, build logs, and other links:

    Concrete information on engine weight: SSO - Honda Engine Drivetrain Weight
    Prelude V6 build thread (lots of cool stuff, worth the read): PP Forum
    A cool build log that discusses OEM cams, heads, cranks, and performance estimates: http://acurazine.com/forums/second-g...-series-873314
    Very interesting, short thread on a 328HP J32a2 using OEM parts only, likely something I will replicate closely: http://www.j32a.com/index.php?topic=2303.0
    Last edited by willbill642; 11-29-2016, 04:54 AM. Reason: Adding links to resources.

    #2
    stick with the regular j32a2 swap. or j35a3 if you want.
    COUPE K24

    Comment


      #3
      Minor extras:

      AC, PS, and Alternator

      This is a track-only build. Currently, there is no power steering in the car and the AC only barely works. Considering how heavy the system is and how I won't be driving it daily, there will be no AC. This leaves only the alternator, which only needs to be compatible electrically. Since I will be reusing the J32a2 harness, this will implicitly be done. Nice!

      Clutch and Shift Linkage

      The stock shifter from a 6spd-J car will be used, drilling new mounts for it in the car. The cables should be able to use the stock passthrough holes, although slight modification may be needed. Not super worried about this, but I'll update with what I had to do to use it.

      The clutch is a more interesting topic. I'm fairly certain I can use the stock clutch master cylinder and therefore the stock pedal. A custom line running from the master cylinder to the slave cylinder would be required, but if the fittings are the same as I think they are, these should be widely available in the aftermarket as generic hydraulic lines.

      Throttle, Cruise Control, and Traction Control

      I intend to use the stock gas pedal, so hopefully a small custom bracket will be all that's needed to actuate the throttle. Cruise control is extra unneeded weight, so that's getting removed. Doesn't help it doesn't work on my car currently. Traction control is called my right foot

      Radiator, Cooling, and Heating

      As it currently stands, I intend to remove the entirety of the HVAC system, for weight savings. This means I can just delete the heater core and associated tubing runs. Quite a few of the Civic J-swaps do this as well, so information should not be hard to find. Outside of this, the stock TL system will just be retrofitted to the car, and upgraded where needed. I'll likely open up the grill area to allow for more airflow, but otherwise there shouldn't be much of anything special here.

      Comment


        #4
        Originally posted by willbill642 View Post
        Mounting, wiring and axles:

        There are a few chassis with V6 swap mounts that are very similar to the CB7, specifically the BB6 aka 5th gen Prelude. The innovative mounts look like they could be modified to fit, but I'm curious about the chassis rail spacing since that might mean a different kit would work better, like for a Civic.

        Axles may be the hardest, or easiest. A lot of the CB7 front end is the basis for the TL front end, so it could be possible to just swap over most of the TL front end and use the stock axles. Unfortunately, there's not a lot of good images online of this, so more research is needed. I could get custom axles made too, but I'm not sure where is good now.

        Resources, threads, build logs, and other links:

        Nothing yet, I'll add stuff as time goes on.
        [/CENTER]
        I have been doing some daydreaming about this swap into my BB6. Apparently, the Acura RL front subframe mounting bolts are the same width as the BB6s (and the CB7s). If you check out the body frame measurements, the bolt holes line up exactly on the front. They are all 1020mm wide. The rear of the front subframe would have to have some sort of custom bracket made that spans the width of the car to mount the subframe to. If you can bolt up the entire subframe, that takes care of the front and rear mounts, the transmission mount, axles, control arms, etc.

        The really good part about this is that Honda also used this ACE body structure on the Accords (7th gen and up?). What that means is that several v6 Accords also have a similar style subframe, although not in aluminum like the RL. It may be possible to grab one cheap and play around with it.

        This guy dropped the whole RL subframe into a Civic and is where I got the idea from:
        http://www.enginebasics.com/Civic%20Type%20RL.html

        Here is some good info:
        http://www.preludepower.com/forums/s...d.php?t=354181

        IIRC, the CL Type-S shifter base bolt directly into the BB6 = CB7.
        Your axle type is dependent upon your intermediate shaft type.
        Last edited by sonikaccord; 11-27-2016, 10:04 PM.

        YouTube Clicky!!

        Comment


          #5
          i dont know what that guy on the prelude forum does, (oil field)? but jesus hes got it going. i read that whole thread. that dudes shit is wild.
          COUPE K24

          Comment


            #6
            Originally posted by sonikaccord View Post
            I have been doing some daydreaming about this swap into my BB6. Apparently, the Acura RL front subframe mounting bolts are the same width as the BB6s (and the CB7s). If you check out the body frame measurements, the bolt holes line up exactly on the front. They are all 1020mm wide. The rear of the front subframe would have to have some sort of custom bracket made that spans the width of the car to mount the subframe to. If you can bolt up the entire subframe, that takes care of the front and rear mounts, the transmission mount, axles, control arms, etc.

            The really good part about this is that Honda also used this ACE body structure on the Accords (7th gen and up?). What that means is that several v6 Accords also have a similar style subframe, although not in aluminum like the RL. It may be possible to grab one cheap and play around with it.

            This guy dropped the whole RL subframe into a Civic and is where I got the idea from:
            http://www.enginebasics.com/Civic%20Type%20RL.html

            Here is some good info:
            http://www.preludepower.com/forums/s...d.php?t=354181

            IIRC, the CL Type-S shifter base bolt directly into the BB6 = CB7.
            Your axle type is dependent upon your intermediate shaft type.
            I'm curious if the TL subframe follows this formula as well, since that means I could just use a TL donor car for almost everything except the transmission, which I plan to source elsewhere anyways. Also, that thread has great pictures of the Innovative mounts and how they mount on the Prelude. I'm fairly certain that they would work in the CB7, especially if the chassis rails are the same distance apart. This swap could turn out to being nearly bolt-in with very little custom work done...

            Comment


              #7
              3rd gen TL or 2nd?

              The 2nd gen TL subframe has a slightly different width. I'll try to make a document to compare all the different ones

              YouTube Clicky!!

              Comment


                #8
                3rd gen would be preferable as it's aluminum and not steel, even on the base models.
                MRT: 1993 Honda Accord SE Coupe (Lola)

                Comment


                  #9
                  Originally posted by sonikaccord View Post
                  3rd gen TL or 2nd?

                  The 2nd gen TL subframe has a slightly different width. I'll try to make a document to compare all the different ones
                  2nd gen, mostly because of the cheap availability of the cars even in the Type-S variety. That said, I could source others especially if the width makes the most sense. I'd love to have that document.

                  Originally posted by Rilas View Post
                  3rd gen would be preferable as it's aluminum and not steel, even on the base models.
                  Is it? That weight difference would definitely be worth it, but I'd be more worried about the width of the subframe over anything else.

                  Something I'm considering is a Prelude subframe for the rear and an Innovative front subframe. I know the front subframe will bolt up, and I think the rear will either bolt up or be close to bolting up. Either way, that means the front and rear innovative mounts for the prelude would work. From there, the side mounts will either work as-is, since they bolt on and replace the stock side mounts, or will require a little work to get them to fit. That would mean the swap kit axles would also work, and the Prelude spindles could be used to do a 5-lug conversion. The TL (or other car) subframes would be cheaper though, and would also allow for the 5-lug swap.
                  Last edited by willbill642; 11-28-2016, 11:34 PM.

                  Comment


                    #10
                    I have had 3 Acura 3.2CL Type-S cars and just finished completely dismantling my first one. I have the full engine/transmission, front subframe (all one piece, unlike earlier Accords and Preludes) and every associated swap part. If you need anything measured at all, or compared to CB stuff, I should be able to help you in a couple of weeks when I head back home for Christmas.

                    Also, the engine is a 100,000 mile (literally) gem that's nearly clean enough to eat off of. In case you're interested.
                    My Members' Ride Thread - It's a marathon build, not a sprint. But keep me honest on the update frequency!

                    Comment


                      #11
                      Also if you want measurements of the 3rd gen I have mine all torn apart right now. The subframe is still in the car but empty, I'm sure I could measure center bolt head to center bolt head as it is. Unless something weird is in the way.
                      MRT: 1993 Honda Accord SE Coupe (Lola)

                      Comment


                        #12
                        Originally posted by Jarrett View Post
                        I have had 3 Acura 3.2CL Type-S cars and just finished completely dismantling my first one. I have the full engine/transmission, front subframe (all one piece, unlike earlier Accords and Preludes) and every associated swap part. If you need anything measured at all, or compared to CB stuff, I should be able to help you in a couple of weeks when I head back home for Christmas.

                        Also, the engine is a 100,000 mile (literally) gem that's nearly clean enough to eat off of. In case you're interested.
                        I'm curious about sonikaccord's document, but mainly I would like about the distance between the front bolt holes, the rear bolt holes, and the distance between the line running between the rear and front bolt holes. It'd be nice to know the distance between the lower balljoints on the lower control arms, and (more specific to the car itself) the distance between the two chassis rails inside the engine bay, specifically the walls itself.

                        If the funds at this time weren't tight (poor college student) I'd jump on it immediately, especially if you also have the 6spd transmission. I'm definitely interested, regardless. Give me a few months (time to plan, build up funds, ect) and I'll get back to taking your spare parts

                        Another random side note, do you or anyone else know about the 3.0CL('97-'99) and it's front and rear subframe? Since it was based on the 5th gen Accord, I'm fairly certain it would bolt up to the CB7 chassis as-is, negating the need for custom subframe mounts. One thing I'm concerned with is the distance between the subframes, since I seem to recall the distance being very different between the two being different.

                        Comment


                          #13
                          Originally posted by Rilas View Post
                          Also if you want measurements of the 3rd gen I have mine all torn apart right now. The subframe is still in the car but empty, I'm sure I could measure center bolt head to center bolt head as it is. Unless something weird is in the way.
                          If it's no trouble, that information would be excellent. Even some pictures, since there's not a lot of good images online.

                          Comment


                            #14
                            I can take the measurements no problem. Pictures will be a few days out. Trying to reassemble the engine first and then, I'll cleanup the subframe. It has a few areas that are totally black due to various leaks. Once cleaned up I'll take some pictures of it.
                            MRT: 1993 Honda Accord SE Coupe (Lola)

                            Comment


                              #15
                              This thread needs more pictures of step by step on how to perform these actions. The future of our very vehicles are at stake.

                              Comment

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