Dyno results! 91 S13 Silvia SR with m7960

[astonmartian]

About time I post about the silvia I've had for almost 2 years so figured posting up the dyno results from last week would be a good start.

Bit of background on the car: Came to US 3ish years ago stock, save for an aftermarket exhaust and now sits, imo, as a solid street car. All parts were bought new save for a few things here and there. Early 1991 production factory two-tone manual with SR. Now sits with ~100k miles on it.

Major Mods:

Tomei m7960 w 11lbs spring
Nismo 740s
z32 AFM
Enthalpy ROM tune (16 psi)
Greddy FMIC/airnix intake
Tomei turbo outlet, 3" downpipe, hi-flow cat, HKS sport exhaust
Blitz id-color dual sbc
Greddy FV bov recirculated
DW 300LPH pump, Tomei FPR
Stock unopened engine, stock HG and cams

The car has been laggy as sh*t since I've had it (same for PO) but once it's above 4-4500 rpm it pulls with a vengeance. Needs cams badly though to really make this turbo shine as it kinda huffs and puffs off boost up top.

On to the pull:

Mustang dyno, 60 degrees, 57% humidity and running 15 lbs of boost.



Results were 266 and 268 whp with 253 and 257 torque respectively. As you can see, the spool is pretty pathetic, with full boost at about 5000 rpm (on the street; had gopro setup in cabin but tuner's hat blocked it).

- The boost spikes about 2psi thus the hump around 5250
- There's a drop in power, then acceleration around 4-4200: Is this because the EBC is opening the wastegate at that time? May be able to turn gain up to get some additional area under the curve.

AFR's in-car on my gauge read upper 11's, leaning out a bit towards redline, no doubt due to fuel pump not being hardwired. Dyno tailpipe shows low 12's for afr

Sent graph over to Martin and he said there's something wrong with the wastegate most likely and that he's tuned a bunch of 7960's that start cooking in high 3k rpm. But I've done pretty extensive researching online and looks like the tomei just spools like poo regardless. On the highway in 4th, I get 5psi at 3k, 10psi at 4k and 16psi at 5k, consistently. I dunno. First SR/tuner turbo car I've owned.

This setup will fall out of boost when shifting WOT to WOT in 3rd 4th to 5th and when the boost comes back on, it hits hard (literally sends shock through drivetrain). Very fun setup on the highway but driving it anything more than a third throttle below 3k rpms is so uneventful I just putz around when off boost. Probably worst setup I could have for a car that's driven most frequently in downtown Boston but I like the Doctor Jeckyl and Mr Hyde personality.



Cheers