reaction to rb25 into rx7

[mikey8108]

i know the power the ls1 would give me and the torque i love torque but also price comes into play how much would u say i could get the complete ls1 and transmission for lets say a five speed and not the t56 since comparing it to rb25 with five speed. a big part of the appeal beside from being different is 1800 for a full rb25 front clip i havent priced it much but iam sure a ls1 swap will double that! i know the fire wall and tunnel would have to be cut because i would want to move the engine as far back as i could with out changing seating and stearing locations because i want a better front to back weight distribution which is better for road race and drift correct? and because the rb is a bit more weight than the rotary. custom mounts and drive line assembly tha will be the hard parts eevrything else shouldnt be to bad.

[SeVa-S13]

I concur.

+1

BUT, 400whp out of an RB26 is even simpler and would hardly be pushing the engine, even bone stock otherwise. Reliability at moderate power (until say 600whp-ish?) is a moot point for both engines. Neither would be a bad swap in any way...

[eh?]

The price for this swap is not cheap. Pricewise, it's probably equivalent to an SR swap. To give you an idea of what it would cost you to do the entire swap here is what I have spent so far:

1999 LS1 w/ T-56 transmission: $3700 shipped- the engine came with a pair of longtube headers that I knew had no chance of fitting so I sold those for $300.

RPM2 232/236 cam: $125 used off E-bayHardened pushrods: $90 brand new off E-bay2005 GTO Oil pan w/ windage tray and pickup tube: $150 shipped

2005 GTO oil pan gasket: $50

1999 Corvette fuel filter (all LS1's, with the exception of the '97 Vette used a returnless fuel system, meaning there is no fuel return line on the fuel rail. The cheapest way to get around this is to use the '99 Corvette fuel filter which has a built in fuel pressure regulator and return line) : $50

Engine mounts: ??? (maybe ~$300-$600 whatever is on the market) I'm making my own so my cost is not relevant to you unless you have the capabilities to make your own.

Headers: This is still in question. Probably custom. I'm going to try LS2 headers as a last resort since GM truck manifolds, C5 Corvette manifolds and F-body manifolds do not fit: Price (anywhere between $100-$600 for manifolds, cheaper if OEM ones will fit, expensive if you can not make your own)

Custom driveshaft: $200-$300

Total Cost: expect EASILY ~$4300+ total without labor unless you have a hookup on the engine/transmission and labor. Mine will probably come in around $4100 because I'm doing my own fabrication and labor.

Then add in the cost of tuning for needed parts: $200-$500. But this is a cost that will be required for either engine (SR, KA-T, RB, or LS1) so that can't be counted.

Horsepower expected with my mods: Probably ~370 rwhp, add an LS6 intake manifold: ~390 rwhp. You could probably get about the same horsepower out of an SR or KA-T but I would imagine the cost would be at least $500-$1000 more (upgraded turbo, fuel injectors at least) (I had a KA-T before and I did all the fabrication on that build (exhaust manifold, intercooler piping, downpipe, 3" exhaust) and I still had ~$3200 into it after purchasing a low mileage KA (27,000 miles), tuned ECU, clutch, etc. and that got me ~270rwhp)

The LS1 will be barely breaking a sweat at 350-400 rwhp and I'd feel much more comfortable beating on it than I did my KA-T.

So bottomline: I feel that you will NOT save any money doing this swap over an SR or KA-T. (Total cost between $4000-$5000+ depending on your level of fabrication skills, the high end being having to pay someone to do it all for you.)

However, I believe the power potential on PUMP GAS and daily drivability (such as startability, idle quality, and reliability) will be far superior to my KA-T.

I know some people will disagree and that's fine, but I've had my experience with the KA-T and I feel for my driving and power delivery preferences the LS1 is a good choice for my S14. Though I wouldn't mind getting a second car and doing an RB swap..I still love turbo vehicles but I want more low end grunt. I think that the RB could deliver that and it would be a fun car.

[mikey8108]

thanks for the input so 4 to 5 thousand at least for the ls1 thats better than i thought but still we will round up for this purpose so 2000 for the rb front clip add say another 1000 for drive shaft and misc parts even though pretty much every part i need i would have between the rx7 and the skyline front clip so we will say 3000 to get the engine in the rx7 with all the labor myself which i will do that leaves another 1500 to 2000 for performance parts which with 2000 iam sure i can get pretty close to the same power as the ls1. i know your not trying to pursade me to do the ls1 over the rb you are just giving me some prices and comparisons and i appreciate it i just thought i would throw out some numbers also so do you guys think if i do it and move the engine back a little bit that it wouild still be a decently ballenced car that could handle well?

[Joe]

when you start talking about moving engines you start talking about big money

a RBx is a VERY long engine. you sure you even have the room to fit it without modifying the rad supprot anyway? id worry about that more than being able to position it in the engine bay perfectly.

[mikey8108]

i will measure my friends s13 engine bay compared to the rx7 it doesnt seem much shorter but iam sure all it takes is an inch to make it to short so that more money has to be spent. i havent bought the engine yet so i want to get all my thoughts and concerns taken care of before i jump in and start spending money. thanks for the help

[Joe]

well in a 240 we only have a couple inches of room to clear front to back...ive got maybe 4-5 total inches between front and rear of free space.

edited because i cant spell

[NightKids2]

well in a 240 we only have a couple inches of room to clear front to back...ive got maybe 4-5 total engines between front and rear of free space.

Thats a lot of engines =P

The LS1 is teh win. With transmission its even lighter than the KA, and gets like 30 mpg.

They make a kit for it now http://www.hinsonsupercars.com

[Shahee1]

Go with a 3 rotor ... it was made to fit in the FC chassis and its not prone to the same problems as the 2 rotor motors. It will also bolt up to your stock transmission and the mounts are less than $100 ... not to mention it will run off your stock ECU ... The RB would really be a tight squeeze due to the transmission ... not impossible just tight ... not to mention that it will put up big numbers easily ... a friend of mine has a 3 Rotor that was installed by JPR Imports and with decent mods it is puttin down 650HP to the wheels without a full tune. He has a date with RActive racing to get it fully tuned. He will surely put down another 100 - 150 to the wheels.

[ScottyK]

http://www.bath.ac.uk/~ccsshb/12cyl/

This should do ur job

[midnightsliding]

dont do it its goign to **** up the balnce of an FC their a blast to drive with good balence once u put a big bulky RB into its going to preform like a stock one..unless u move some **** around for better balance who knows i put an RB into a 4 door boat and alot of ppl dont liek that idea but i did so do what ever u want building cars are fun thats what its about.

[mikey8108]

i want that engine thats is the only thing that will make me happy putting that into my little hatch no but seriously i think iam going to do the rb25 into a 510 iam tired of smog laws what about that?

[wawazat8402]

Measure the length of the engine bay. You can make anything fit anywhere (not being dirty, hehe) if you ahve the money and fabrication skills. I thought about it, but the Power weight ratio would be retarded (way too light of a car IMO). Also, it seems like you would have to have an access panel under the dash to get to the back sparkplug. Its been a couple of years since I took the measurements, but Im pretty sure the 510 engine bay is quite a bit shorter than the 240.

[mikey8108]

thanks for the info. when my friend gets back with my engine and if i can find a 510 i will do i write up and keep taking pictures of the progress.