slayerx7

iTrader: (4)

The more and more I look into this the more and more a fuel injected 13b with a turbo or 2 is the best way to go... I found a twin turbo REW motor and a custom 6 speed for it for $2500 both. but you know what they say, if its too good to be true, it usually is. Ill be checking it out though, on the offchance its as good as claimed. And yes I think it would be worth the cutting / welding / 1000 headaches to make it work.

More than likely this thread is going to turn into the 400rwhp 13b goal

RXn407

I would stick to something tried and true. If rotary shack has what you need for your 12A to make your HP goals then go with that. Like someone mentioned earlier you dont want to get head over heels into a project and then sell it half ways through. for example my T2 was all stock except for exhaust, safc, boost control, intake and fuel cut. thats pretty much it and since i bought the car and babied it so much the greddy boost control stayed at the stock 7 lbs, the suspension was upgraded and I had a VERY FUN CAR!!!! I couldnt beat z06 or nothing but it was super fun for me and thats all that I cared for. good luck and have fun.-Erik

PaulFitzwarryne

The figure I use is a loss of 17.5% from flywheel hp [fwhp]. As rolling dynos give variable results[usually optimistic], the measured loss could be around 15% of factory engine performance figures. There is some good data on the rwhp: fwhp ratio from the controversy on the RX-8 power outputs.

I would suggest you need 165rwhp to be certain you are getting 200fwhp. Both are calculated as SAE bhp. You have to be careful with Japanese figures is they are frequently given in JIS bhp, for example the 12A in the 1984 RX-7 is shown as producing 130fwhp! If measured in SAE it would be 112 fwhp; remember their engines were more powerful than the US market engines.

BridgePorted12A

iTrader: (6)

Hey, I have a question that you all might be able to answer. It's a little off topic but I saw that Slayerrx7 is using a 465cfm Holley carb. I just bought a 1985 Rx-7 12a that has a 1/2 bridge port and the owner, if I am correct, put a 650 holley on it w/ an after market fuel pump running 6 psi. My question is: is this too big/too much fuel for this car?

Ryan

slayerx7

iTrader: (4)

The fuel pump is right on. I was told that 650 is good for a full bridgeport, so if you replace the jets with smaller ones, you should be ok. It may be able to run with the 650 as is, but probally not optimally. Wouldnt half a bridgeport be an extend port? I thought it was the 'eyebrow' added to the extend port that made it a bridge port?

trochoid

iTrader: (6)

Depending on the area and lingo, an extended port is sometimes the same thing as a monster port or J-port.

If one were to ask Sterling he will tell you a 650 is too big for ANY 13B, even a full bridge. His reasons are velocity, the venturies are too big. After putting a 650 on my 1/2 bp, and driving it around the block, once, I tend to agree with him. The carb was on for less than an hour. After the trip around the block, the Holley came off and the Mikuni went back on. I couldn't believe how anemic the Holley sounded. It was also very lame and flooded easy, didn't leave it on long enough to do any tuning. I think a 500/550 with vac secondaries would work much better.

For the comment about the SDJ header, speed costs and that header has been dyno proven to produce more hp any other header on the market. New they are 650, iirc. If I wasn't looking at turboing down the road, I would have one on the widebody.

PaulFitzwarryne

A half bridge is when the primary intake port is extended only some 20% with an additional small third port cut close to the housing leaving a bridge to retain the corner seal. The result is the usuable powerband is some 1600 rpm lower than for a full bridge, trading better torque low down for acceleration against top end power.

PaulFitzwarryne

[QUOTE=trochoid]Depending on the area and lingo, an extended port is sometimes the same thing as a monster port or J-port. QUOTE]

Quite right, meanings vary widely. In several countries the term extended port covers any increase in port size from mild to the wildest full bridge. When in the late 70s I first was involved with rotary engines in the UK, the US term of street port was not in vogue. The talk was just " I am extending my port". People just experimented until they got it right, there were no available commercial templates.

BridgePorted12A

iTrader: (6)

[QUOTE=trochoid]Depending on the area and lingo, an extended port is sometimes the same thing as a monster port or J-port.

If one were to ask Sterling he will tell you a 650 is too big for ANY 13B, even a full bridge. His reasons are velocity, the venturies are too big. After putting a 650 on my 1/2 bp, and driving it around the block, once, I tend to agree with him. The carb was on for less than an hour. After the trip around the block, the Holley came off and the Mikuni went back on. I couldn't believe how anemic the Holley sounded. It was also very lame and flooded easy, didn't leave it on long enough to do any tuning. I think a 500/550 with vac secondaries would work much better.[QUOTE=trochoid]

Ya, the car is running WAY to rich. When I go WOT the almost bogs down for a second, kind of like turbo lag and takes off. The owner said this was b/c of the mec secondaries on the carb. My question is if I change out the jets, making them smaller, do you think this should solve the problem? And of course having the carb dialed in would also help. I am idling at around 1800-1900, way too high, correct?

Ryan

trochoid

iTrader: (6)

With the Mikuni I have, and everyone has said it can't be done, I can get my idle down to 800. It is very lopey and bogs badly from a stop when set there. I usually run it 11-1200. The problem with the big Holleys is since the velocity is down, fuel atomization is poor, this robs hp, causes pooling of raw gas, hurts fuel mileage and can lead to easy flooding and fouled plugs.

Now, if one were to use the Holley throttle body with fuel injection and a larger than stock aftermarket turbo, then becomes a whole different animal.

fcdrifter13

I ran a 600CFM Edelbrick on a stock port motor. 600CFM is not the amount of fuel its the volume air(if I am not mistaken). If you are still looking for an intake Tofuball might part off my old one. Contact him and ask him about it. Its a ported RBintake and the port job needs cleaned up a lil.

slayerx7

iTrader: (4)

Ok i just put the holley on my 12 a, linked the throttle rod to the choke lever, and WOW WHAT A DIFFERENCE!!! Cant wait for the header.

However, I think the best way to be making a lot of power is to be getting that REW motor which is apparantly out of a '97 rx7 (Europian or canadian model) bone stock that should make about 265 or 270 HP and in a 2300lb car (probally less now) WOW!

I think I'll start a thread for the REW to Fb swap - Excellent write up to Kevinbtz!