SR Swappers... Top mount turbo VS. R&P Steering Conversion.

[paradime]

Short of RHD cars, you rarely see an SR swapped early Dat without a top mount turbo manifold. It's a matter of the stock SR turbo configuration's down pipe interfering with the old Datsun's steering box. The other day I saw a R&P converted 510 with a bone stock SR bottom mount setup and the wheels started turning. Shit, when you really think about it, it seems the difficulty of converting to R&P to deal with the down pipe issue would be more than counterbalanced with the ability to keep all the SR's stock parts, and the super compact configuration, while avoiding all the heat BS and expense of converting to top mount. Not to mention you'd be getting serious improvements in your steering. So why don't we see more SR guys going this route? Is it because the aftermarket parts guys wouldn't make as much money, or am I missing something here? 

 

 I'm genuinely interested in measuring the pros and cons of these two approaches in swapping the SR, so if this subject has already been covered in the past, Please, spare me the "Oh no, not this shit again". I sure as hell couldn't find it, but if you know where there is some meaningful perspective on this subject, just point me in the right direction and I'll abandon this thread.

 

Can we also assume the debates over wether or not to swap, the coolness of swapping one motor vs another, or any other stale opinion about the SR has definitely been COVERED. I'd really like to gain some insight on this subject, so If you want to share your diatribe about some unrelated topic, man up and start your own thread.

[Icehouse]

I've always thought the same thing.  Instead of building all the custom parts to do a top mount I've just spent the time to convert to rack and pinion on the SR swaps I've done.  I've got a parts stack started for my next conversion :)   In the past I've always used a combination of S12 parts.  Some guys have used MR2 racks which I may try it what I'm working on now doesn't work like I want it to.   

 

 

 

 

Here is a picture of my 68 two door with a rack and pinion setup.  My favorite 510 every.   Drove so awesome!   

 

 

 

 

I tried swapping to the holy grail of racks…. The 280zx manual rack, turned out it was so narrow (which would have been nice, could have removed some bump steer) that the steering shaft wouldn't pass the block :(

 

 

 

 

 

After all the fucking around with that rack and crossmember I got pissed and tossed the whole thing into the recycle bin at work haha :)

 

 

Nillon's car!  

 

 

 

 

 

 

 

 

[paradime]

Hey Icehouse, Thanks for the feed back. I think the MR2 rack conversion looks like the way to go. it's well documented, seems pretty straight forward, and the parts are a Dime a dozen (pun totally intended).

 

85-88 MR2. are manual, so no worries with power steering pumps etc. IF you still want PS though, I've seen people use a column mounted electric power assist unit (like on Goichi's coupe). The MR2 rack Is 'rear-steer' so it's all ready to go just as you need it. Also if you swap the MR2 tie rods for 2, 1985 toyota cressida drivers side tie rods, it narrows it just the right amount so it threads right onto the passenger side rod ends for the 510.  

 

 

Very clean setup. 

[Icehouse]

I really like the power steering though. Such a nice added bonus around here. Lots of our roads are rutted really bad which makes driving on the freeway unpleasant unless you have power steering it dampens the pulling out so nicely. Can't wait to start version 5 :)

[paradime]

I don't know what front wheels, bump steer solution, or caster you're running, but trying to parallel park my auto-X 510 with 7" R compound tires is like driving a frick'n tank. I can't say I enjoy man handling the car around a tight track either. The steering feedback is nice, but having to wrestle the car around corners hardly seems worth the trouble. I know R&P would help in that respect, but adding PWR assist would be pretty damn cush.

 

WIth respect to the different swapping approaches, I guess if you were building a monster HP car you'd have to go top mount to get a t3, or t4, but if you upgrade the stock SR setup with a t28 and some ECU re-flashing, you can still push 14-16 psi and get upwards of 300 hp. Let's face it, in a little Datsun that's silly ass power. I would say that 80% of the SR swaps out there are making less than 300 hp, so what's the advantage of top mount in that situation? Am I missing something here? 

[ggzilla]

The advantage of top mount is that it doesn't interfere with the steering gearbox.

[paradime]

The advantage of top mount is that it doesn't interfere with the steering gearbox.

True Ggzilla, but if you can solve the steering box issue by converting to R&P, is there any other compelling reason to go top mount in stead? I know the folks at Mckinney, Dat sprort, etc have turned a nice profit selling all those top mount parts.  Seems to me that if someone was fabricating MR2 rack converted X-members, a serious argument could be made for taking the other path. 

[ggzilla]

MR2 rack is the wrong width. But power steering will help damp the bump steer. In the end it works.

 

If you can afford the top mount, it looks much cooler than a hidden turbo.

[Icehouse]

True Ggzilla, but if you can solve the steering box issue by converting to R&P, is there any other compelling reason to go top mount in stead? I know the folks at Mckinney, Dat sprort, etc have turned a nice profit selling all those top mount parts.  Seems to me that if someone was fabricating MR2 rack converted X-members, a serious argument could be made for taking the other path. 

 

I'm no Toyota dude but I've heard that some of there other cars have the same sized rack but have a power option.  

 

 

 

 

 

MR2 rack is the wrong width. But power steering will help damp the bump steer. In the end it works.

 

If you can afford the top mount, it looks much cooler than a hidden turbo.

 

David you always say that! haha  It can only be the wrong width if you know what the right width is.  The bump steer with factory components on a lowered 510 is terrible I mean so bad if any suspension parts are at all worn its almost not safe to drive.  If your definition of "wrong" is excessive bump steer I would say the factory components fail as well.   You should really buy this book.  Out of all the suspension books I've read plus all the stuff online this dude explains everything the best.  

 

 

 

 

 

 

 

I do agree a top mount does look Bad ass!!!!!   

 

 

 

I don't know what front wheels, bump steer solution, or caster you're running, but trying to parallel park my auto-X 510 with 7" R compound tires is like driving a frick'n tank. I can't say I enjoy man handling the car around a tight track either. The steering feedback is nice, but having to wrestle the car around corners hardly seems worth the trouble. I know R&P would help in that respect, but adding PWR assist would be pretty damn cush.

 

WIth respect to the different swapping approaches, I guess if you were building a monster HP car you'd have to go top mount to get a t3, or t4, but if you upgrade the stock SR setup with a t28 and some ECU re-flashing, you can still push 14-16 psi and get upwards of 300 hp. Let's face it, in a little Datsun that's silly ass power. I would say that 80% of the SR swaps out there are making less than 300 hp, so what's the advantage of top mount in that situation? Am I missing something here? 

 

 

Have you ever driven a setup 240sx?  Do you feel like there power assist takes away from the steering feed back?  I don't I feel it allows the car to be driven better.  Me and some work buddies used to race go-carts at least once a week in the summers right next to my work.  After 10 minutes my arms are about to fall of because of the difficulty of the steering and thats a go-cart!  I feel that manual steering can take away from the driving fun.   I also say that from driving a 510 with both setups.   I've never "raced" before although I did grow up in the woods so I was a self per claimed rally driver :)   

 

I see no need to do a top mount setup.  It would have to be a pretty big turbo to require it.   Something like this maybe.   Who needs 600 HP though.   

 

 

[BadWagon]

I'm no Toyota dude but I've heard that some of there other cars have the same sized rack but have a power option.  

 

 

 

 

 

 

David you always say that! haha  It can only be the wrong width if you know what the right width is.  The bump steer with factory components on a lowered 510 is terrible I mean so bad if any suspension parts are at all worn its almost not safe to drive.  If your definition of "wrong" is excessive bump steer I would say the factory components fail as well.   You should really buy this book.  Out of all the suspension books I've read plus all the stuff online this dude explains everything the best.  

 

 

 

 

 

 

 

I do agree a top mount does look Bad ass!!!!!   

 

 

 

 

 

Have you ever driven a setup 240sx?  Do you feel like there power assist takes away from the steering feed back?  I don't I feel it allows the car to be driven better.  Me and some work buddies used to race go-carts at least once a week in the summers right next to my work.  After 10 minutes my arms are about to fall of because of the difficulty of the steering and thats a go-cart!  I feel that manual steering can take away from the driving fun.   I also say that from driving a 510 with both setups.   I've never "raced" before although I did grow up in the woods so I was a self per claimed rally driver :)   

 

I see no need to do a top mount setup.  It would have to be a pretty big turbo to require it.   Something like this maybe.   Who needs 600 HP though.   

 

 

 

I do :devil:

[sssr20det510]

AE86 Rack is same width as mr2 but power

[Icehouse]

I do :devil:

Haha. What kinda power are you putting down? I can't remember if my holset could have been setup as a bottom mount.

 

 

 

  

AE86 Rack is same width as mr2 but power

 

 

That's what I thought. Wait until you see what Sam and I are working on. Going to be sweet! The Toyota rack is the backup plan if your idea doesn't work.

[paradime]

have you guys considered an electric power assist unit like this?

 

 

 

No need for the pump and all the lines under the hood, and you'd get a tilting wheel. Hell that Cadillac style Bro.

[Icehouse]

I've thought about that and yes it would make it cleaner under the hood.  I never took the chance to drive Rich's coupe even though he offered, so I don't know how well it would dampen shitty road feedback.  I do remember him saying the way it was setup it would tapper off as the car climbed in speed so I can't imagine it did.  Yes that is an option.  I like the tried and true hydraulic setup at least for now.  

[paradime]

Ggzilla, Totally agree the top mount looks WAY cooler. I'm sporting my little 3071R twin scroll propped high and proud. I wouldn't tuck that under even if I could. 

[BadWagon]

Haha. What kinda power are you putting down? I can't remember if my holset could have been setup as a bottom mount.

 

Oh I'm bench racing... If I have 3-350hp when I'm on the road I'm sure I'd be  happy

 

 

 

 

 

 

 

 

 

 

 

 

for awhile

[DISLEXICDIME]

The power steering is nice . When me and phill got to autox together phill got tired a few runs befor me because he had a steering box and I had a power rack.

 

The quick response and mad angle my rack gave me saved my car many times . Now I am stuck with a steering box again and it sucks . I am going to go ae86 rack when I have the cash nelson has had good luck with them