adeckbar

what turbo and i/c would i need to get 400 rwhp i would like to get it without a stand alone computer and with the help of a fuel computer and boost computer only i no i need a front mount i/c, 1200 cc injectors upgraded fuel pump and a free flowing exhuast my engine will have an aggresive street port and all mandrel bent ic piping as well as mandrel bent 3 inch exhuast splitt by a flowmaster y out of summit turned backwards to dual 2 1/2 inch mandrel bent pipes to dynomax race magnums

Scott 89t2

full to4 turbo, nice front mount IC, 4x720cc injector would be close, maybe want slightly bigger. standalone ecu is a must.

vaughnc

carbed anyone.

InfiniIIIREX

A turbonetics T-66 would give you plenty of turbo for that number.

adeckbar

there must be some way to get that much power without a stand alone ecu has any body here done it or is it just easier wih a haltech or somthing i do not want that much power now but would like to have it available for the future without having to go the stand alone route just yet

hurleyboi514

or you could just buy a neon...

Felix Wankel

4x720cc is not enough for 400 rwhp. My friends TII ran lean and blew at 339 (I believe) rwhp with 4x720.

RP's injector calcultor shows 4x720 even at 100% duty cycle (very bad to do) only supporting 415 at the flywheel, maybe about ~345 at the wheels.

qwck10th

A standalone is a good idea.

BDC, IIRC, put down 426rwhp with 4x720's... But if you do the math, he musta been cutting it close. Maybe the HP calculators (RP, RCeng, etc) are bogus? I believe the calculators, and think that he was close to the edge. Lotsa factors though: intake are temp (liquid/air IC), fuel pressure, fuel quality, duty cycle%, etc...

2x550 + 2x1600's is much safer.

IMO, the T66 is not needed . A good port is important. That said, a T60-1 or T62-1 gets you to your HP goal more cheaply. Meaning, you don't have to run the higher pressure ratios (boost) to get the same bhp. Less boost = less heat, lower intake air temps, and 92 octane is ok.

Take a look at Kurgan's setup.

My .02

Scott 89t2

the RP site is stock fuel pressure which is only around 35psi. cain's was much higher, and also he was at 100% duty cycle which is not good. you'd need bigger injectors to run that much with reliabilatly.

go_speed_go

400 rwhp?

Just go here and start reading: http://brfoundation.com/RX-7/

Kurgan

WRONG!

Here's a dyno of BDC's FC turning just over 424 rwhp at 17 psi. Guess what? He has 4x720cc injectors.

Felix Wankel

17.5:1 A/F ratio?? I hope that wasn't under full throttle... What were his injector duty cycles?

RETed

Anyone who has done the analysis of the run knows that the 4x720's were MAXXED OUT.&nbsp They were way over the safe 80%-85%.&nbsp I've seen the datalog on that run.

If you run the numbers, Felix Wankel is also right - 4x720 cannot support 400hp to the rear wheels at "normal" fuel rail pressure.

Now, for the original posters original question...
InfiniIIIREX is right, the T66 would be my recommendation too.&nbsp If you can read compressor maps, the 60-1 was not designed to run over 15psi of boost - the T66 is optimized to 20+ of boost; the T66 would run way more efficiently than the 60-1 due to larger compressor section and lower boost to produce the same amount of power.&nbsp The 62-1 would give you 400 at around 18psi, but a T61 would let you do that with a bit more efficiency.&nbsp These are all Turbonetics parts.&nbsp If you check the 60-1/62-1 models versus their "T-series" (i.e. T61/T66), the price differences are negligable[sp?].

Now, as for trying to do this with a stock ECU - this is not something I would recommend.&nbsp The stock AFM is just CHOKING the engine at that kinda power levels.&nbsp John Duarte (noted east coast FC drag racer) was pounding his brains out trying to get to 400hp at the wheels.&nbsp Going with a Wolf3D easily broke the 400hp to the rear wheel barrier with room to spare...




-Ted

maxpesce

400 Reliable RWHP?

Start w/ a 20B and then its Easy!

InitialD FC

iTrader: (1)

You do not need a stand alone ecu to get 400rwhp. It is a good idea, but not a necessity. An HKS AIC with another set of stock turbo 2 injectors in the intake manifold will cover you to 500+hp. I ran 4 550s in the intake manifold, with a t04e and made between 380-400rwhp. Never made it to a dyno with that turbo, so the number is not exact, but it was a huge increase over my 319rwhp setup that i did dyno. That was done with 2 extra 720s and 15psi on a busted t04b. The intercooler pipes were terribly made because of a lack of mandrel bender, or welders back then in my area, haha.

So yes, you can do it with a 60-1, 62-1, it will almost be maxed out, but it will do it. Its just the matter if you want to spend the extra money.

You wont need haltech, additional injectors will cover for fuel.

Spearco IC will do it, you can get them any size you want, so i say they are the best choice.

adeckbar

thank for the info on my post i just took the engine back out of the car after it overheated and found the rear rotor had lost the apex seals and probaly took out the adjoining housings with it so i pray for a generous tax return from the tax return gods anybody have a rear 87 tII rotor housing, middle and rear side housing for sale the guy here who does rx7s can bearly take them apart and one in ten he has built runs so he has them all rebuilt some where else and wont let me get any good parts from him well i guess i will start throwing money in a jar for now to get the thing running again

Kurgan

Just simply stating that it was possible. I hate it when people say that something can't be done...

rotonomo

<cough>
http://www.v8rx7.com
</cough>

NZConvertible

I doubt the AFM is suitable for 400rwhp, not because of it's size (it'll be a huge resiriction but air will flow through anything if you push or pull hard enough), but because I think it will have reached its measuring capacity. the little flap will be fully open and even though airflow into the engine is increasing the signal stay the same and the ECU gets incorrect info, resulting in a lean-out. Intercepters won't fix this as they simply modify the AFM's signal so won't see any change in load. AFAIK, when you max out the AFM this way, it's time for an aftermarket ECU.
BTW, for the early trapdoor type, the airflow required for 400rwhp would be doing about 200mph through the AFM!

Felix Wankel

Just because you can do it doesn't mean its particularly smart....

Kurgan

But saying that it can't be done when it can isn't particularly smart.

Turtle's TII

The problem with using the formula to figure out what injector size to use is it uses a .5 BSFC, try the formula with a .35 BSFC which is more realistic. This is more of a tuner debate, one tuner will run a lot bigger injector than another. So if you are planning on using the Mazda crappy computer ask your programmer what size he wants you to run.

NZConvertible

A rule of thumb I've heard a few times is 8cc/min per flywheel kW. This is based on actual thermodynamic calcs of the amount of energy fuel releases when burnt (43.5MJ/kg) and how much of that energy actually reaches the flywheel (23-24%).
This means 4x720cc/min injectors at 100% duty cycle would be good for 483hp at the flywheel. That's pretty close to the dyno prinout above when you consider drivetrain loss.

rx7_ragtop

Brian IS cutting it close, he'll tell you that. He could make more power, but didn't have the injectors to support it, he was running out of fuel at high boost/high rpm, hence the low rpm his power peaked at. If he added a couple extra injectors (even small ones) hooked up with his secondaries, he could probably crack 500 at the wheels, or at least get close... but that would be about max on his turbo.

Brad

rx7_ragtop

p.s. he'll ALSO tell you that he needs a bigger turbo.