1.88 liter, ABSURDflow goodness, 2871R 52-trim .86 A/R, open exhaust, 21psi, stock intake manifold (chart was basically the same at 18psi, stock IM blows.)

Attachment 201243

True, I forget our hotparts are worth ~25whp :giggle:

There's at least a 48, 52, & 56 trim GT2871R as well, all with different compressor maps (obviously). So throw that wrench into the works too.

I mean just look at my dynos, more or less the same thing. Same compressor, slightly larger turbine. journal bearingz.

I never understood why one needs fast spool on the street, yet thats wat everyone says. The car will put about just fine off boost, the turbo is not much of a restriction under vacuum. If you want boost, downshift/learn to drive. Having driven a 2.4L car wth a 16G, it spooled too easaly. I dont need boost to get up to speed at a normal pace from a stop light yet it would. A turbo that spooled 1000 rpm later would have been great. Even on my 2L car with the same turbo and low 8.3:1 compression it spooled more often than I needed. It was neat to have the instant response, but the car did not need it and it did not make it significantly faster when being driven hard.

Now if you are atuoXing or on a tight track, then I can see where a low boost threshold and low transient response time is a big deal. But on the street if you are going fast you should be above 4K pretty much all the time anyway. As long as the lag is not bad getting onto the throttle in the high 3K range does it really matter if it spools at 3K or 3500? I am assuming though that 'on the street' does not involves some really slow tight corners. Even then I suspect a potato would be fine, but have 0 experience with it.

48 and 56 have the same height, the 52 stays efficient at slightly higher pressures but doesn't make as much ultimate power as the 56 trim (like 10-15whp). I did the 52trim.

Anyone have any 16g dyno's? I can't believe people are running chinease turbos when you get get DSM 16g's so cheap.

I guess I am different than everyone else cause I'd just weld my own manifold. I guess it helps to have a welder.

Do you guys really see that big a difference between the log manifolds and the "AF" designs? Anyone have a dyno comparing the 2 different manifolds?

You need to get on a dyno so I can see you rnumbers at 22 psi. I wish you had a 1.8 so I would have a better idea of what to expect on my car. I would like headroom to 350hp

Spare, I promise you, if you're not making your boost target by 3500rpm on a street DD miata, it takes all the fun out of it.

You may not believe me, but drive two stock miatas, one with a 2554 and the other with a 2860. Even if the 2860 makes 30rwhp more at the same boost level, you'll prefer scooting around in the 2554 setup.

I'm sure others will agree.


see how a 2554 and a 2871 would compare:

http://www.boostedmiata.com/gallery2...serialNumber=2


the larger turbo really only benefits above 6K....when's the last time you were going around a fun corner on the street at 6K?

^ That is really good to know. Thanks.

When I stop being an unemployed loser and get my damn car, I have an E316G and TiAL 38MM literally sitting on my shelf. 0 shaft play, the turbo had no trouble making 20+ psig on my Laser. It's driving me absolutely bat-shit. Whats worse is that I am headed back down to PHX early next week to help my buddy put my old Eagle/Wiseco 4G63 into his '91 Talon. That car ran low 13s all day with 90 psig compression accross the board. My motor makes about 165 IIRC. One good 3rd gear pull in that car an I will either

A) Start crying like a bitch.
B) Man up, get a car, and put my shit on it.
C) Steal someone elses car.


I am leaning toward C.

End Hijack. Sorry folks.

2554R is a FUN street turbo. It's a lot of fun to roll off a stoplight, plant your foot at 2500rpm, and immediately get kicked in the rump. Having owned the 2554 and the 2871, the 54 is a WAY better street turbo. It's a better track turbo, too, TBQH. (too bad it won't make ~400whp.)

this is what tim saying dawg.

I'll compare Shueind's dyno to mine. I've driven his 1.8L a bunch of times and really like it over mine on the street, get on the highway and let hit redline and I miss my dinky 1.6L

http://www.boostedmiata.com/gallery2...serialNumber=2


what really ruins you is a good absurd setup that has the of best of both worlds:
http://www.boostedmiata.com/gallery2...serialNumber=1

I am with Braineak, It all depends how you drive & what you are out to do. If you drive the car every day you really appreciate the quick response.

I noticed this when I drove my friends car (turbo VW 2.0 8v) a t3 60 trim vs my car with a 16v head and a t3t4. I had about 40 whp if you look at the dyno, but his car is way more fun for me to drive. Just roll on the gas at any rpm and you go. Must easier to modulate the throttle in corners too especially with front wheel drive.

If you drive everywhere wide open, do a lot of track days, street racing, etc the bigger turbo is nice, but for a daily, I'd rather have a nice fat turque curve. Just my $0.02

What is the set up on that red dyno above? I really like that torque/power curve? (well if you can call it a curve, its more of a line.)

My 2554R setup made STIs feel laggy.

I love my T25. I have thought about going to a T3 setup similar to Brain's but I think I enjoy having a small turbo more. My car is my DD and plenty fast for me right now even with my MBC disconnected. I mean, on stock wastegate i'm already fighting for traction with my torsen in 1st and 2nd. I never even have a chance to get to WOT before I get wheel spin. At 12-14psi my 1st and 2nd gears feel completely useless.

My next upgrade is likely going to be welding the IWG shut and getting an EWG hooked up.

wrong.

some hondas are capable of revving to 9, most are not.

the B18B from the LS integra is very similar to the mazda BP in power output, power band, rod ratio, etc. It limited to about 7500 rpm on the stock bottom end.
people still run 30r and even 35r turbos on them.
the miata community is phobic of large turbos, there is no denying it.

Is this a sneak peak at whats to come 400 whp?

Welcome to "happy medium" land, enjoy your stay.

I should note that "happy medium" land sucks. In ABSURDflow land you get to short shift into 5th at 3500rpm and throttle steer, lol.

With the Tein Flex I have traction with crappy Nitto Neogens in 2nd and lots and lots of power and torque.

They are pretty much just drag racers but also consider that even the B18b head still flows A LOT better than any head that goes on a miata.