George D

Please, we are kids with the unfortunate need to make our favorite, "Sports Car" Best of Breed. Most of the folks building these cars "playing" honestly with today's rides have issues: I'll share mine. Owned three 944's. Owned about 23 other sports cars, tracked most, had a fling with a few. Been married for two decades, and bought-sold many cars...only missed the 951's SOLD!

My wife has the records, done time with other cars. Some were faster, handled better, but I can drive the 951 well, fits me, and chose to build her as I like. I'm not one to take a loss, but $ here isn't relevant. Love these cars.

Neat piece of my current 951: The previous owner is getting married next weekend in Sonoma, and we've become dear friends. I have a shirt saying: Sonoma makes wine; Napa makes auto parts. Bringing that T Shirt to the wedding, know I'll wear it when appropriate.

G

333pg333

Really? In what way Shawn? I'm definitely running a bigger cam than most of you guys. Shouldn't I be at least as advantaged by that or is it that as you guys are mostly running stock cams that you are seeing larger benefits when playing with ign?

Cam: Intake 293 x .537"
Ex 282 x .502"
114^ Lobe Separation advance 1^ cam.

KSira

Here is a dyno of a 16V with short runner intake for comparison. Dyno done @ 0.8bar. 8:1 compression head/cam is stock. (The torque peak is from the WG hitting 1bar at boost build up)

refresh951

Well, struggling to understand why. Over 10 degrees difference is a lot . I am sure cam timing has some impact. Most aftermarket cams have some built in advance also. Could possibly be due to differences in the squish area. Sid and I are running a bit down in the hole. Corleone, however, also said he got benefit to almost 40 degrees IIRC and I would imagine his squish area was similar to yours. The slower the flame front, the more timing required.

I am going to do some more testing and research on this and I will let you know what I find.

Thom

I am wondering if Corleone did not actually use a cam with relatively modest duration and overlap, considering his GT3582R 1.06.
With my short runner intake my engine ran more cleanly up top with the 9R cam than it did with the "272" cam I have in now. The cam brought more mid range than top end. It was not until I cranked up the boost from 1.2 bar to 1.5 bar that I really felt some big gains up top with the "272" cam on the short intake.
I am tempted to think Patrick that you may now need to go to the 1.06 turbine housing to reduce the torque drop past peak torque rpm, if adding ignition did not bring anything.

333pg333

Thanks Shawn / Thom.
tbh...the car is really pretty fast now and I'm thinking certainly for myself, once we crank up the boost a little on the bigger layout it's going to be damn rapid...but I do take your points. Maybe larger hot housing wouldn't be too difficult to try.

George D

I'll find the dyno from Jeff's 8 v head with expert port polish, solid lifters with full HP at 7200 rpm. We think the bottle neck on my car is definitely the mostly stock 8v head.

refresh951

I agree, the head is a MAJOR factor. Patrick's head flows about 250 cfm at full lift and my head about 210 cfm. Sid did a large valve head on his new motor that also flows about 250 cfm. I have a 250+ head in the works but am not going to install until next Winter.

Also, definitely clear 8V advantage going large bore to help minimize shrouding with larger intake valves.

George D

The internal runners in my SFR intake have been completely redone using a flow bench. The 928 TB, full 4' intake, cad designed vertical intercooler, and three filter intake will flow enough air. We realized on the dyno tuning, the head was being "outflowed". I don't know if that's a scientific term, but the intake side of the equation pointed directly at the head. If you drive this car, it's not wanting. Cars like Patrick's, and Patrick himself, requires every gram of potential.

This intake resides in the front driver fender. Not pretty, but it flows air!

George D

Two dyno charts from a previous 89 951 with a K27dr6, head work, etc. These were done one day apart. The first run showed 330whp 340tq. We installed larger injectors and a new chip then eventually recorded a run at 23psi. The 19psi run was done with 91 fuel, and the 23psi with 100 octane pump fuel. This setup was ideal having full tq by 3500rpm. Neat driver. Sold this car to Jeff in LA about 12 years ago. The car now has a 3.0 and continues to embarrass many top end LA rides.

Where are those 500whp 2.5 dyno's? Like to see them.

These dyno's were done in 1999 using Huntley Racing's MAF with their Split Second fuel controller. This was 15 years ago! Few cars back then were as fast as this hot 2.5 951!

refresh951

Pretty similar to my best 2.5L dyno at 18 psi:

Tom M'Guinn

Looks familiar. As best I can recall, here is my best 2.5 dyno....clearly back in the ARC2 days before I could get a solid handle on the AFRs....

George D

Sean and Tom,

We have similar results. I'd like to see similar dyno charts above ours-with similar lines. I'm not a gambler, but don't think they exist.

Thanks for sharing your charts. Good to know we shared similar work towards the potential of the original 2.5 951 engine many years past with continued passion towards the 951's evolution.

Driving a well sorted 951 is one of the best auto experiences I've known.

G

Eckan

Stock 2.5-88 short block, O-ring, top decked, widefire gasket
ARP head studs
Ported head 47mm intake 235cfm at 0.495
Lindsey racing valvesprings
Late N/A 9R camshaft
Stock intake and exhaust manifolds
kkk/borgwarner hybrid turbo, 51mm in cold/61mm ex hot 8 housing
Tial 38mm Wastegate
Modified endtank on intercooler
2.5" Ic pipes
Full 3" stainless exhaust
Ecumaster EMU running full sequential
Ls2truck coils
Bosch -044 fuel pump
Bosch 1200cc injectors
E85

Turbo maxed out, the tuner choose to increase boost at mid range to make the power band broader.

Mottryck=Exhaust backpressure

//
Erik
Sweden

v8killer

Here is my Rouge M-Tune at 22psi on E85.