88RXVERT

iTrader: (5)

You hear people say that convertibles are heavier then the coupe and stock from the factory that’s true..they weight in about 300 pound heavier, for 2 reasons the Top and they always come Loaded, but depending on the weight deleting steps you take and the application makes a huge difference. Fact is this: a striped down vert is WAY lighter then a stripped down coupe , because you can do all the same weight savings changes to coupe that you can do to a vert… with the addition of the removal of the top, the top motors and everything to do with the top…so for the same application the vert will always be lighter, making it a better choice for almost all racing applications.

Rob XX 7

iTrader: (8)

if the car is a basket case its a good chance the motor is crap anyhow, it is nice to get all the parts in one complete running car but they are becoming hard to come by.

decent cars that maybe had some body damage usually get parted out, I sold a car in the fall that was a great donor car, original TII that was a little rough body and interior, needed exaust, brake work, tires, etc but it was a factory manual steering/AC car and had all its bits and pieces, I sold that car for $1700.

Funny enough someone on the board ended up buying it from the guy I sold it too, who was not a member of the boards.

Removing enough weight from a street driven vert to get it to coupe weight leaves you with a **** car.

arghx

iTrader: (3)

Here is my input, and this is based on my recent experience of rebuilding my T2 engine (I have an 88 T2) for a 450-500whp T04R setup. I want to discuss what your fixed costs are, your engine management options, and why I believe you need to gather more information before you make a big decision here.

Here are some of your major fixed costs:

new gaskets, seals, and springs for engine internals. You need that no matter what rotary option you choose. You will need a new turbo, intercooler, and probably upgraded radiator.

You need an engine management solution. My opinion is that you should go with the s5 Rtek 2.1 . it is in beta testing stage, and by the time you are ready to get the new engine fired up (it always takes longer than you think it will) it should be ready or nearly ready. This is coming from a guy who has a Power FC standalone. The knee-jerk "go standalone" response you get on here is rarely tempered by the unfortunate reality that, while standalones will run safely with just a few hours of tuning, they won't drive smoothly like a stock car without HOURS AND HOURS AND HOURS AND HOURS of tuning. I'm talking consistent idle and cruise AFR under all conditions, throughout an entire year's worth of weather conditions, without going the easy route and just throwing a ton of fuel in there to keep it from blowing up. Ask any tuner, professional or experienced amateur, and they will agree how time consuming it is. With the Rtek You also don't have any crank angle sensor noise issues (Haltech problem on some models) or possible wiring mistakes to deal with. All this assumes your stock n/a harness is in good shape, and if it isn't you can get a good condition n/a harness no problem.

Ever since the Rtek has had rpm vs boost timing control I would say it is the best option for builds up to 350rwhp that have turbos with 3" inlets. The myth of the "restrictive" AFM is just that, a myth to a certain extent. There are ~350rwhp dynos on the stock s4 AFM with Rtek (search the dyno sheets section). The reality of the matter is, exhaust restriction is far far more important than intake restriction in the case of our engines. And besides, the rtek guys are working on an AFM removal feature anyway. Any setup that only needs 720/1000 injectors will be fine on the Rtek, and you should be able to do 350rwhp with that combo. The amount of driveability tuning needed on the Rtek is a fraction of what is needed on a standalone because the factory O2 sensor feedback and correction maps for ambient conditions are pretty good.


Let's get back to costs for a second. Here is where you can get fucked hard: rotor housings and other hard parts. What if you tear down your motor and you've got a chip in a coolant passageway on the irons? What if you've got chatter marks on the housings? Suddenly rebuilding that n/a motor isn't so cheap anymore, not unless you halfass it and use marginal parts.

So what is the solution? Pull the motor and tear it down. Then figure it out from there. Who are you to say how much a rebuild of the n/a motor will cost? I mean if you reuse everything sure it will be the cheapest option... but you said you want reliability. SPEC OUT EVERYTHING. measure every side seal clearance and write it down for example, or just get new ones. Measure your step wear on the irons, your chrome flake/edge wear on the housings. Measure the free height of all your springs per FSM and Haynes specs.

www.rebuildingrotaryengines.com has videos on how to spec out hard parts.

If your n/a motor is in worse shape than you think, you may be better off just getting the jspec, tearing it down, and mixing/matching parts from the two motors. And when you get the Jspec motor you get the manifolds and crap which solves a lot of problems, and then you can slightly modify your n/a harness to make it work.

But if you tear down the n/a motor and every hard part looks great (and measures great according to proper inspection procedures), then suddenly getting the JDM motor isn't as attractive of an option.

The only option IMO is to keep saving up your money while tearing down and specing out the motor you have before you make any major decision. And if everything's trashed on the n/a engine and you see a good deal on a V8, well that is at least an option (although not one I would choose).

Then you need to go and start pricing things, creating spreadsheets of your possible options and factoring in an extra miscellaneous cost to cover crap that may just come up. This is the only way to make an informed decision. This is how successful businesses make purchasing decisions--they gather as much information as possible and project all the scenarios using educated guesses. I have almost every dollar I have spent on my project itemized, including extra tools and fluids I have had to buy. It requires discipline, but it is the only appropriate way to track everything on a really big project. Too many people just go buying **** with only a vague plan and a vague budget, and then they throw in the towel when the cost in time and money gets out of control.

I am attaching a spreadsheet of my buildup budget (turbo upgrade and engine rebuild) for you to see an example of how to cost a big project.

RotaryRocket88

iTrader: (7)

Most of the added weight in a vert is because of all the additional steel put in to stiffen the chassis. There's no roof for support. For one, you've got the wall that divides the trunk from the top/spare tire area, which doesn't exist on a coupe. If you start cutting out much of that metal, you'll end up with horrible chassis flex.

Like Rob_XX_7 mentioned, in either a coupe or a vert, if you start getting the weight down by more than 50-100 lbs., it's going to be crap on the street. It's going to come down to what you're willing to sacrifice. Besides, you can always bolt on a bigger turbo .

88RXVERT

iTrader: (5)

Vert -vs- Coupe weight depends on series as well, I bet a stock S4 vert weights less then an stock S5 TII. Do a little research on the matter...Icemark (RIP) was putting people in there place when it came to this misconception all the time. Its was only in the S5 did they start adding all the weight in both versions.

RotaryRocket88

iTrader: (7)

All the weights are available in the standard specs thread.

It's close between an S4 vert and a S5 TII though. 3003lbs vs. 2987 lbs.

88RXVERT

iTrader: (5)

BS changing the front bumper to fiberglass will get you close.

88RXVERT

iTrader: (5)

I lost the bet...but only by 16 pounds (thats less then the verts head rests)....the driver can go on a date with Jenny Craig and make up for that difference....LOL

So you got a S4 vert next to a S5 TII, the guy in the S4 removes the top and motors taking over 200 pounds off his car..what does the the guy in the S5 TII have to do to match this weight savings? A couple weeks of work and **** car??? YEAH. Whats the vert need..a garage to park in? LOL

jjcobm

iTrader: (18)

You still haven't sold that? Nice car, I would imagine this swap was probably really time consuming for you.

Yeah thats what the v8 guys I know told me, $10k is what you will need around to have everything done right in the end, it's something I have in mind for either swap regardless...

Since you are here already, how did the handling change when you put in the iron block compared to the lighter rotary? Did it feel like you had a bit more weight up front to lug around?

Yes this is something I'll have to keep in mind...

Yes everything will be done by me. I don't want anyone else touching my precious.

Rob XX 7

iTrader: (8)

a stock urethane bumper weighs nothing, did you mean removing the bumper support?
Who sells a fiberglass bumper support? You know the stock bumper support is a composite plastic correct?

I can literally FEEL the difference with my coupe and vert, the vert just feels heavier.

As for the hours of tuning to get a standalone car running properly- I dont want to argue with people who might have more tuning expierence because I have none myself, but what I do have is a Wolf controlled car that runs, drives, starts, and idles like it came off of the showroom floor.

The iron block TII I have drives awesome, I can feel no ill effects of the swap, I have always meant to find someone with scales to see exactly how the car is balanced.


Everytime I bought something for my swap it turned into hundreds, damm fuel system ran me over $900.

jjcobm

iTrader: (18)

I agree with this completely, I was thinking of just buying a diff from japan2la, which regardless of the swap is something I need, then just buy the engine/tranny I want to swap in.

Thanks for that sheet, that is something I was hoping to look at...

I had an idea the convertible can be lighter, but I wasn't aware of the fact that the factory weights were almost the same. Good information.

Ok well last night I did more researching and I stumbled on something that I think I want to do with my vert. Let's just say I have always been a toyota guy and when I saw this I fell in love with it.

1JZ or 2JZ swap. The only thing that I couldn't find at all was any documentation on how these guys end up wiring the electronics after the block sits in the car. I wouldn't mind taking the time to wire everything in myself, it just would be helpful to have more information on this. rx7club was down last night so I will take a look here later on to see if I can find anything. Japanese muscle car engine sure beats having an american v8 anyday

I appreciate all the feedback so far, it has helped me clear my doubts and questions I have been having about swapping engines in my vert.

clokker

iTrader: (2)

This attitude, while admirable and maybe even justified, may not ultimately be in your project's best interest.

There are so many aspects involved in a major project like a swap that it's hard for one person to be master of them all.
Obviously, not knowing you personally, it's impossible to say what your capabilities are but it's safe to say that there will be some aspect of the job(s) that you don't excel in.
For those areas, there is no shame in subbing out the work- in fact, it's shows more sense and maturity than a blind insistence on doing everything yourself.

Just something to think about...

jjcobm

iTrader: (18)

Yeah what I ment by that is most of the work within my capabilites will be done by me, I know I lack alot of skills when it comes to fabrication, which is where I am willing to have someone else help me out need it be, but I believe I do have the skills to do anything electrical or bolt on when it comes to the swap. Of course this doesn't mean I can't have anyone help with a set of extra hands.....

Rob XX 7

iTrader: (8)

if you go with another motor you need the harness and computer for that motor.

The body harness on a vert contains all the wiring for the car itself, the rotary engine wiring only has the wiper harness in it which can be removed ( 3 wires ) so using XX brand of motor you need XX wiring harness and ECU.

88RXVERT

iTrader: (5)

I have owned both my 88 vert and S5 GTUs...and I don’t intend to argue with you about this issue, because so many variables come into play, you just painted the picture here with some pretty broad stokes to say the least when you said:

“Removing enough weight from a street driven vert to get it to coupe weight leaves you with a **** car”

When you take into account that the S4 vert weights 3003lb and the S5 TII Weights 2987 lbs, a 16 pound difference, you may lead people to believe that taking 16 pounds out of a S4 vert will leave them with a “**** car”, and it’s simply not true. Screw the front bumper…you could make up 16 pounds of weight by swapping out the FC stock radio, vert to coupe seats, among hundreds of other possible 16 pound weight saving options. My vert weights WAY less than a stock S5 TII coupe and I would toast it both off the line, in top speed and put it to shame from a style stand point as well. I have done nothing to jeopardize the structural integrity of the car, unless you consider the spare tire mount and sound deafening material as a structural component; I took all the lightest components from each series.

Rob XX 7

iTrader: (8)

I just cannot believe that my s4 vert weighs the same as my s5TII car, they just do not feel the same at all, I have owned 4 other coupes and they also felt lighter. I have also pushed each one around and they also feel different then as well.

Dont know what it is, or what the REAL world weights of each are, but damm if they dont feel different and sorry but I still cant believe they are within 16lbs of each other no matter what the spec sheet says!

As for the broad strokes- relax a little bit, when people start talking about removing tops and top motors thats when I say FROM A STREET DRIVEN VERT, who the F wants a vert with no convertible top? thats just crazy talk.

88RXVERT

iTrader: (5)

If you read what I have written in this thread more logically.. you will find that I have said all along that the applications need to be taken into account. You take this issue out of the street category and hands down the vert wins.

Now, I will admit that the two cars do drive very differently but that has everything to do with body design and weight distribution, keep in mind the vert were built on a completely different production line then the coupes and they do seem to have a lower center of gravity.

Rob XX 7

iTrader: (8)

i was only explaining my "**** car" comment, I said if you take all that weight out of a street vert it becomes a **** car, which is what a convertible with no roof is.

I feel anytime you take carpet, heater, wipers, radios, etc out of any car it becomes a track car, AKA a **** car.

RotaryRocket88

iTrader: (7)

Are either of you taking into account that a turbo swapped vert will weight MORE than the published 3003 (S4) or 3045 (S5) lbs.? The turbo engine, transmission and rear end all weigh more than the original NA parts. It's hard to get the exact number, but it's going to be about 100 lbs. more, if all 3 pieces are swapped in.

So, you're talking 3103 or 3145 vs. 2987 lbs for a turbo vert vs. an S5 turbo coupe.

But really, who cares? Both are going to be fast cars, and neither one is really all that heavy. Heavy would be the 4000 lb. boats that Dodge makes.

88RXVERT

iTrader: (5)

1) But you are/were WRONG. removing 16 pounds does nothing of the such.

(A top and motors are about 220 pounds... which was not a suggestion just a hypethetical situation based on application.)

2) I agree...but you dont need to remove any of those things to make a S4 vert the same weight as a S5 II, take out the spare tire..DONE

If taking out a spare tire out makes a car a **** car..then take your spare tire out and sell me your **** car.

88RXVERT

iTrader: (5)

Yes..I have taken that into account..this was only to prove that you CAN make a vert weight less then a S5II. So many variables...your right it dont matter...just pisses me off when people act like the 16-150 pound differances between series cant be offset, without compromising the car.

Rob XX 7

iTrader: (8)

we can go back and forth all day, my comment was directed at taking the top and the top motors out of the car, I did paint a broad picture saying to get it to coupe weight, but I was merely responding to someone suggesting removing the top and its motors, next time I will be more specific

and I will argue until im blue in the face that the cars are not that close in weight, im sure there have been enough people who actually weighed thier real life cars to get accurate weights, I can believe what I want to believe because I drive both cars back to back and you can tell when one car is lighter then another.

And im really comparing when my vert was NA to its current turbo condition to my coupe.


Most people remove the PS and AC, which probably offsets the difference in weights of the NA motor compared to the TII motor, a stainless manifold takes alot of weight off the cast iron versions, but a FMIC is more weight then the stock TMIC

RotaryRocket88

iTrader: (7)

I don't know if it will help or make things worse, but...

This is a quote from NZConvertible on the chassis weight difference.

clokker

iTrader: (2)

IMO, the weight and horsepower numbers are irrelevant.
It's the feel of the car that matters, and that is totally subjective.

My brother's Porsche Carrera was a very fast car but didn't have the experience of speed that my '67 Morgan did.

The 3rd gen V-8 might be inferior in many objective, quantifiable ways but feels like a monster in the gut... and isn't that what we're looking for?

Rob XX 7

iTrader: (8)

88- your quote is perfect for a turbo vert, its basically like having a passenger in your car, and I dont know about you guys but I can IMMEDIATLY feel the difference in the car when I have a passenger.

Sometimes real world feeling and paper stats are not that important, a 300hp vert is a great car, but it aint fast.