qwck10th

Subject covers it. My goals are:
o ~380rwhp. 400 is ok too<grins>
o less than 17psi
o flat torque curve (as flat as the BP will allow).

I'm building a tubular mani. to mate to div.tang. turbine.

I'm having trouble running calc's on the compressor maps b/c I don't know the VE of a BP'ed motor. I've been using 1lb. mass air = 10 bhp. Anyone?

How much A/R will the BP need?

What about shops other than Turbonetics? Can I buy a Garrett directly? It seems like Turbonetics mixes & matches the Garrett parts then rebrands them. What about KKK? Any maps for those?

+rant+
There's waaaay too much "smoke and mirrors" (read: BS) in the turbo business! Arrgghh!
+/rant+

Thanks for reading.
Steve C.

My calculations (PSI v. BHP) are at http://www.se-rx7.com/gallery/maps.html
Other mods are in the .sig

peejay

I think it was soul assassin who put down a hair over 400rwhp on 12psi with his BP turbo. But I don't think he has a T04.

I'm starting a similar project to yours... I'm already working on the engine, deciding exactly how to port it, putting in extra dowels (better safe than sorry eh?). there is still sooo much to learn but it's more fun than the N/A street port I built. I'm also looking for "only" 400-410rwhp, just because that's roughly the power of an F40, and an FC and F40 are similar in weight. It would be a nice comparison for laymen. The trick is, I want to be able to do it on 92-octane pump gas....

Greg

Get a 60-1 standard or a 62-1,, they will do you just fine

qwck10th

I remember John D. had problems with the TII tranny a while back. He was at 425whp (dunno how much torque) at the time. Roger Mandeville told a friend the TII block starts to "twist" a bit past 400whp (450bhp). So, those two items present limit$ I need to stay within.

I picked a BP b/c the car is not a daily driver, and I already had it apart to replace a water seal.

Greg
Yeah, the more I look at the 60-1 map, the better it looks. The 62 looks pretty similar. I'll admit to having the T66 itch, but I can't afford the pressure ratios it likes.

Thanks guys,
Steve C.

peejay

AFAIK the FC and FD transmissions are pretty much the same internally, except for minor gearing differences, the way the clutch works, and the rear mount setups. (FC has a mount, FD uses the PPF) IOW they should have about the same power handling.

I'm sure you'll be duly corrected for the "twisting" comment, but the way I understand it, the factory dowel pins do not adequately support the rotor housing in the lower driver's side of the engine where peak combustipn pressures occur. Given that the factory dowels are at the top driver's side (the oil flows through there) and the bottom pass side (right below the exhaust ports) the rotor housings will want to flex outwards, which pulls hard on the upper dowels and can crack the rear end housing in the oil filter area. I've HEARD (and I'm sure I will be corrected ) that Series 4 engines tend to crack at about 350bhp (~300rwhp?), Series 5 engines are "better", and Series 6 and up (meaning all FDs) will let go at 700bhp. A while ago in a dowel-pinning flamefest, someone here noted that he built an FD engine, well tuned, that would crack the rear end housing right at 700hp. Dowelled the engine, problem solved.

I basically don't want to take any chances. I'm aware that the problem isn't "twisting" of the engine, but given that this car might have to be pressed into, and relied upon for, daily-driver use, I want the block to be a brick s**thouse.

HWO

Brian D Cain is making 498Hp at the flywheel with a series 4 block and isn't breaking end plates - why cause he isn't detonating.

just like seals, detonation is what kills the end plates, sheer HP pressure alone will only crack the plates at around 650+ rwhp

Boostn7

I agree with HWO as far as cracking end plates...

Detonation is usually the main culprit for cracking end plates.....unless you're making huge amounts of horsepower (600RWH+)

Af far as transmissions....I have 5 blown Turbo II trannies on the side and I've been running a FD tranny this whole season without breaking...I think there's some improvement on the Fd trannies...gearing is the same as the 89-91 T-IIs.

My car has made a bit over 500RWH with a slipping clutch in 3rd gear and as far as my highest torque was either 413 or 418 RWT

Later,
John D
10th Ann Ed T-II
10.80 @ 130mph
11.1 @ 131mph-drag radials

qwck10th

I stand corrected on the end plate issue.
Shows ya what I know...

Its good to know I can step-up, and take the block to 500. I'll keep my eyes open for a 3g tranny.

I don't hear much from BDC anymore - sometimes on the RXTech and Haltech lists.

I should finish my ports this week - hopefully. A few more porting pic won't hurt, will they?

Gotta go,
Steve C.
BRAK L8!

Gearhead

iTrader: (1)

How does one go about dowel pinning an engine? I have a 2700 mi '87 TII motor for my vert that I am going to bp if I ever get around to it, and I have been somewhat concerned with the end plate cracking issue. I'm surely not going to make 600hp... well, not for a while at least. How much stronger is the series 5 engine? Should I be worried? Thanks,
Don.