Turbo Size for 500+WHP
 

I'm back for some advice after not posting for a long time, just been reading. You may remember me from the atrocity of a thread that is stickied on this subforum.

Anyways, my NB isn't my daily anymore, I have it stripped down to a bare shell currently and have been stitch welding the seams while I wait on my cage kit. The intended and sole purpose of this car is to drag race in the 1/4 mile, ideally I'd like sub 10 second ETs but I'll have to wait and see as the project is not even close to done yet. Let's get some specs out of the way before I get down to business:

Engine is an 01-05 BP-Z3:
Supertech 84mm 9.5:1 Pistons and Wiseco XX Rings (I will switch to Wiseco pistons after a season, my tuner in Dallas says I will have no issue with the Supertechs but I still think this is the limiting factor as to how much power I can make right now)
Eagle Rods
ACL Race Bearings (.0020" mains, .0025" rods)
ARP Head and Main Studs
Boundary Stage 2 72-psi Pump
ATI Damper w/ Fab9 Trigger Wheel
Volvo Springs (I am going to get the camshafts reground to either 264/264 or 272/272, stock VVT cams as of right now)
Supermiata Reroute
Some other small stuff like LS2 coils, Cometic HG, Skunk2 manifold, Audi DBW throttle body, etc.

Transmission is ZF 6-speed and KMiata kit (I have the transmission, still saving for the swap kit), using 22-spline 6-puck sprung ACT clutch. 3.23 Getrag LSD on 26x8.5" slicks and 24" skinnies up front. Should trap around 150mph, will be using a parachute. Poly suspension bushings, 10-point 1-5/8" .083 wall chromoly 8.5 second rated cage, MaxxECU Race and custom PDM/wiring harness, W/A intercooler (no heat exchanger, just an ice box in the trunk). Using 2000cc ID injectors and Walbro 450lph pump (had 900cc DW injectors but sold them as it won't be enough fuel). Still deciding on coilovers, most likely GC with Koni Race dampers but that may change.

The reason I still have the Supertech pistons is because I already had them when I was building the engine several months ago, and according to my tuner he says it'll make the power safely with the E98 fuel I will be using; luckily there are several race fuel suppliers in Houston.

Onto the turbo manifold. It is a T3 flange, sch10 1.5" primaries, 304SS front/bottom mount manifold with a 40mm EWG flange and 4 EGT ports on the underside of each runner near the head flange. The turbo mounts roughly where the A/C compressor used to be (if this manifold sounds familiar it is the same one from this thread). My original choice is the Precision 6262, as the previous owner had a 6266 on it and it spooled at some crazy high 5500rpm. Being a drag car I don't care much for lag but still, 5500rpm spool with a engine only revving to 8000 is pretty damn laggy.

Would you guys recommend any other turbo? Maybe something from Garrett? I've considered an EFR as well but I fear it will hit the radiator fan shroud since EFRs are pretty long. That and they do not have an EWG T3 housing.

This isn't a huge rush, mainly because this project is super expensive but I'm determined to make it happen. Eventually I would like to make over 600WHP with a 4-link setup in the rear and possibly get into the 8 second range but that is far far far from now as it's going to take at least this entire year to get this one running down the strip based on the rate I am getting all the parts in for it.

It is amazing that you reference such a dismal failure (Gingerich). You'd hit 8 seconds if you pushed it off a 1/4mile cliff.

disregard reply

Maybe some math guys could do some quick calculations for us. Miata dropping from cliff time. You'd have to take into account the density altitude, the front Cd as well as what the drag would be if it remained flat. Tumbling of course would be much more complicated.

c r i n g e

Lol, didn't he claim over 400WHP from a EFR 6258? I think he also had some crazy claim on a 2554 or something.

Grain of salt.

Seriously. If that's your God and you must live in a miserable world.

The new perfect hotness for your needs is the Garrett G25-660. Technology keeps moving forward.

With the K Miata transmission kit and everything else you listed you shouldn't have any issues hitting those numbers.

Yup, I have one of these on order to bolt to a K24Z3. Can't wait.

Yep. Spools like a 2560 and makes power like a 3076 (or better).

Wish they made them with a T3 flange...

Hard choices

Think the Precision is just the best option in this case, pretty much all you see at the drag strip anyways. Wondering if the $600 cost increase for the ball bearing CHRA will really aid in spool time all that much.

In for something that will never happen

pretty sure my 6258 was close. the FM2 never had a chance.

Oh, I have no doubt that a 6258 can generate enough TQ to slip a FM2. They are spec'd at ~350lbft.

I'd go EFR if not the newest Garretts

EFR7163 has a T3 option for EWG.

I know its off topic but have you considering running a built for drag racing automatic transmission and converter setup instead of the 6 speed since you are doing a drag build? You may want to investigate that option before getting too deep in the zf swap.

Mind pointing that out to me because only the 7064, 7670 and larger turbos have T3 and they are all IWG.

I just like driving manual. Yeah an auto would be more consistent but it takes a lot of the fun away (to me). I chose the ZF 6-speed because it can take a lot of power for one, but also because I happened to come across one. I was originally going for a Getrag 260 but my tuner sold me the ZF 6-speed for a good price and it barely has any miles on it.

Edit: There are also a few ways I will be helping myself out; with a staging brake of course but my tuner also wants to limit power on launch with the DBW Audi throttle body I will be using since my gearing leads to a very high starting line ratio even with a 26" tall tire. I won't really be doing any roll racing but I'm still going to put a switch in for the rolling anti lag just because the MaxxECU Race supports it.

Devolution- when people do rolling start "drag races" because that's about the only thing the car can do anymore.