As a senior design project at my college I will be converting my Rx7 to run on E-85, as well as a full rebuild and port job.

Here are my current specs for the project.

Series 2 Rx7, model S
91 JDM turbo II motor.
87 Turbo II trans
Haltech E6k
Borg warner To4b turbo 60-1, 1.15 P-trim divided turbine with tubular manifold.
V-mount intercooler,
dual walbro 255 pumps

(4) 1680 fuel injectors (is this enough)

motor will be tuned on a superflow 1000hp engine dyno.


we will be doing a large street-port on the motor, along with 3mm seals.

I have heard that super high HP application need certain mods done the the block to keep it from deforming. Dowel pinning comes to mind, but I dont know what that involves.

Other than porting and 3mm seals, what needs to be done to the block for 500+hp levels. We plan to run 20-25lbs of boost (maybe more) on pump e85.

 

well i put down 562whp with nothing more than 3mm mazda seals and a half-bridge port.

 

nn

 

Ive been told that turbo wont go 500 hp.

 

I did 424whp on 18psi on a stock motor, and a t67. if pushed harder I think my stock motor would make it to 500 just fine.

 

The motor will make 500, although you will be squeezing every ounce of air from that 60-1 to get the number.

 

A stock 13B will make that power without issue (without 3mm apex seals) but that turbo will struggle getting there, might have to supplement it's lack of airflow with some nitrous to hit 500 at the wheels.

 

^^

 

Did you think of adding dowels or studding the motor?

 

Ive heard these terms before but dont really know what they mean. We have a full service machine shop at the school. Mills, lathes, water jets, misc CNC stuff, the works.

So machine and fabrication are open.



and as for the injectors and the turbo, right now I have a 60trim compressor on the turbo, and have always planned on a 60-1 for my gas application.

I would like to stick to the bearing/turbine setup (which I believe is more than enough for these numbers, Would a 62-1 be better? will I need to go bigger than my 3in turbo back exhaust?


My budget for this conversion is about $5000 (which my dad is donating, seeing as he plans to write it off somehow) + whatever I can scrap up.

Nitrous is not an option, 500hp is the goal, as it makes about 275 right now at 7 psi. and we want to double that.

 

They told you that your turbo will struggle to get there. You don't NEED 3mm apex seals, plenty of people are still running OEM 2mm seals no problem in that hp range.
From what I've heard, the new-er engines come already reinforced, so deforming isn't as big of a problem as it was w/S4 engines.

5K should be enough given you already have most of what it takes to get your car there.

 

well $5K for

New fuel pumps (im running a A700HP right now)
new filters,
new hardlines.
new ethanol compatable 6-an stuff.
fuel injectors
FPR
Possibly a new fuel cell (my current cell is anodized aluminum and may not be compatible), but we would probably just fabrcate it from scratch out of stainless.

Turbo upgrade to 62-1

rebuild kit

I bet that comes close to shooting the budget.

the idea has come up to convert it to direct injection (which we have done successfully on snowmobile engines. But that is a real long shot.

 

I am curious if you would really need an intercooler for E85 with fuel injectors in the stock locations?

 

I'm not going to run a intercooler.

 

And i thought i was a picture *****.

 

The rew is far more reinforced than even most s5 blocks on the dowels..
at least on mine

after just seeing that difference alone i would never build a high hp engine with s5, let alone s4 irons without some sort of pinning or oversized doweling


Call me crazy but I swear to you mounting the engine from the rear iron (rew) vs the intermediate iron (bt), gives less force being transmitted through the rear dowels

IMO 2mm >3mm seals... they will do whatever 3mm will, and 3mm really only caught on because it gives the option to mill out and use otherwise unusable rotors

 

i know, i need to stop

 

The engine is mounted on the front with a SE front cover and engine mount.

I was planning on adding a torque brace at the rear cover.

 

How are planning to convert your rx-7 to e-85? I'm interested because I am wanting to do the same thing and all I can find are e-85 conversions for piston engines. What size/type injectors are you running?

 

where are you planning on adding injectors... 4 1680cc/min injectors is nto going to cut it. you are going to need at least 6. might as well runn 6 1680s and 2 smaller injectors so getting things to idle nicely is easier. If i were you i would get an e8 and the fjo injector driver box so you can get 3 stages of injectors.

 

4 1680's might be enough, remember that he can crank up fuel pressure to get more fuel flow if needed.

I still think the 60-1 and 62-1 will struggle, you need over 60 lb/min at 20+ psi to get to 500 rwhp and that number is on the edge of the published map on both turbos. This means efficiency is low and outlet temps very high. Relative to the 60-x turbos, a T66 will be in it's sweet spot near peak efficiency. With no IC I would say the T66 is a much better choice, plus I would run a q trim exhaust wheel or with a p-trim I would run a larger (1.32?) hotside. If you decide to run a Garret turbo then that opens up a lot more options.

3" exhaust will work, it's proven to work, but bigger is better especially on a stock port motor and as well for spool.

I'm a bit jealous, wish I could have done a project like this for school, using someone else's money

 

a well priced turbo for what you want is the to4r, plain jain journal bearing. try to get a good hotside ( .96 or 1.00 )

 

I was planning on switching my car to e85 but there arent eneough gas stations around here that carry it. I still managed to convince my parents to fully fund my project . Since you are running ethanol there is no reason to run boost pressures bellow 20psi. the to4r should be a good choice. if you have the extra money you can go for the to4z.

as far as cranking up fuel pressure so you can get away with 4 1680s... i dont know about that. You can do what you want but i wouldnt risk my motor on it. you have access to a machine shop so making an additional injector holder should be easy.

gl

where do you go to school anyway? Im at washington university in st. louis, they wont let us do something as fun as what you get to do, lucky basatard.

 

I'm a Automotive Engineering Technology (AET) major at Minnesota State University in Mankato.

and as far as injectors

what about (2) 1680 primaries and (4) 1000cc (or so) secondaries. Anyone know if I can have one channel run 2 injector on a E6k

 

Im not trying to step on toes, so don't be offended, but 500hp now days is a walk in the park. Hell, you can do it on a stock re-man. You don't need to do a thing to the motor to handle 500rwhp.