RX7nonSEQ

A quick summary of the last 5 years for me. Small streetport 13b and dynos done on a powerdyne Mustang Dyno
Swapped turbos to nonsequential and made 240 whp @12 psi on stock intake/intercooler/3" straight pipe
Upgraded stock intake filters and intercooler to Pettit Coolcharge lll, 299 whp @ 12-13psi
Went through 3 primary turbos driving it hard in the river valleys of Kentucky and decided to opt for a single to alleviate the amount of OEM turbo swapping, its a pain!
Installed 8374 IWG turbo with cast shorty manifold and made 340whp @ 14psi. This has been reliable for several years with a track day mixed in. However, I did have to go bonkers on porting my wastegate on the turbine housing to keep boost from creeping up to 17psi. This is likely because of the Turblown manifold and me opting not to choke the exhaust to less than 3".

If you want 350-400 crank hp, 8374 is the answer if you're into the reduced packaging/simplified system idea. These numbers are achieved at the lower end of the turbos efficiency range, and therefore you will need to design for that low boost threshold. If you have a stock port and an exhaust with a muffler/cat/resonator, you probably won't have to port the turbine housing.

If you're open to externally gated turbos, there's many options that will yield better low boost control.

billyboy

The 350, does depend a lot on the dyno......and the operator you use.

Without reading through it all again, this car https://www.rx7club.com/build-thread...ebody-1047574/ achieved somewhere around 400 from memory on the 7670 in my presence on a dyno dynamics, running ethanol. If you are going to run straight pump, probably 1 bar max is your safest option. In the latest iteration he went to a 8474 instead of an 83, which might be detailed further on, before the usual life and babies intervened to force a sale!

TeamRX8

iTrader: (2)

some people have struggled to hit 400 whp on a stock port REW and an 8374, but generally speaking it should be possible. It becomes easier and higher potential with porting. However, while it can reach mid-500 and higher, that’s on E85, the boost jacked way up, and a long list of engine mods to support and make it possible. In the same light, some people struggled to hit 350 whp with the 70mm IWG too. It does require amping it up some compared to the 8374, as would be expected.

there’s a big 8374 thread in the single turbo area and the vs 7670 info is in there with real world results, and also the big 7670 thread there too.

good luck with your rock and a hard spot dilemma.
.

dguy

iTrader: (8)

I think what being forgotten is that - for the most part - those who are asking for 350-400 are trying to do a 'moderate' build. Part of that build mentality tends to be both simplicity and to be bulletproof as possible; an IWG 8374 (with proper wastegate control) is that in a nutshell. I also much prefer the 8374 at low boost to a 7670 at high(er) boost from a driving perspective. It's the perfect blend between resposne and turbo 'surge'.

When people start talking about being able to make 400 with a 7670 on ethanol, they seem to be missing the point.

Forgive me if I'm making assumptions about the power/build goals, but that's my .02 on the the matter.

I should also add: if someone asks me about a turbo setup for 300 I'd suggest a 7670 all day long. I like to design things that will last in the racing environment I work in - 45 minutes to 3 hours of matted driving so my numbers may seem lower than what gets thrown around.

Gregoryp

iTrader: (1)

[QUOTE=dguy;12592259]I think what being forgotten is that - for the most part - those who are asking for 350-400 are trying to do a 'moderate' build. Part of that build mentality tends to be both simplicity and to be bulletproof as possible; an IWG 8374 (with proper wastegate control) is that in a nutshell. I also much prefer the 8374 at low boost to a 7670 at high(er) boost from a driving perspective. It's the perfect blend between resposne and turbo 'surge'.



That’s more what I’m interested in moderate build, on pump gas, simplifying engine bay not having to run AI and keeping it driveable

TeamRX8

iTrader: (2)

that’s what half of us on the hard spot side of the equation have been saying all along …

mr2peak

I made 436whp with a street port on 1 bar 8374IWG. That was on E20 pump, with water sprayed on the intercooler from a watering can during the run, so definitely a "hero" run. But still, it made quite a bit more than I was expecting that's why I'm cautioning against the 8374 for a 350 goal.

How is the response of the 7670 EWG? With a larger A/R, that would push the power up a bit, still spool super quick, and hit that 350 goal.

I still think twins are the answer. This is one of the few 90's JDM Hero cars to come with sequential twins. Even now that's pretty rare and is a cool showcase of the Mazda rotary engineering. Part of me wishes I had gone upgraded twins. Maybe some day I'll take the smallest EFRs and build a twin sequential system..

mkiv98

iTrader: (5)

No mention of the 8370 kit that turblown has been offering? I haven't found much info on it besides that it's supposed to be an in between of the 8374 and 7670.

WANKfactor

iTrader: (1)

It's the 8374 coldside with the 7670 hotside.
worst of both worlds for a Rotary.