MarkRobinson

A bit of history: I built this motor in 2013 with all new bearings, ported exhaust manifolds, polished heads, fresh valve job (stock angles), 30# injectors, full fuel system replacement, stock chips, 93 octane, and it Dyno'd 290/290 with cams timed per the manuals. NASCAR radiator and rear-mounted/shrouded oil cooler keep the temps too low, need to block off a bit.

Car runs great as I'm close to 150mph headed into turn one at TWS.

Before I prep for Texas Mile (turbocharged) figured I'd tune it in the Porken fashion with his 4.0 chips, cam timing, MAF Ohm-ing, and colder plugs.

I'm thinking that if the car made 20-25rwhp over the usual stock chipped M28.43, I might be approaching 330-335rwhp if all goes well.

Bets and or wagers?? I say north of 330rwhp.

MarkRobinson

Pics come one post at a time...iPad

MarkRobinson

Another

MarkRobinson

MAF was only 10 ohms off

MarkRobinson

A lost key resulted in major rewiring of the ignition including some fun stuff

MarkRobinson

I'm proud of my cocky flash to pass button on the wheel.

Shift light is set for 5500 to remind me to keep it lower in the corners...but will wind it out on the straights.

MarkRobinson

Forgot to say, my cam timing was WAY off...used Porkens kit to verify that I've been running with bank 1-4 set at 9 degrees retarded, and bank 5-8 was set to 1 degrees advanced. Weird.

mark kibort

so, it did 290rwhp with 30lb injectors, but stock chip? did you do some programing, because thats a lot of fuel vs the 24lbers that come stock on the 85 motor, right? (what was the reason the S4 vs the 85 was 19lb vs 24lb? )
anyway, you have the cams timed, so i dont think that is a big gainer unless they were way off before. ive been off before and that was worth about 15hp.
new chips? we havent seen any gains for the S4 with chips, but i heard there was with the 85s, so im saying another 10hp there. why colder plugs?
what do you mean, stock ecu but full fuel system replacement? replaced with new or modified?

my guess 310 rwhp. I think the main downside is that the 32 valve 85 has the smaller valves vs the S4 which can make 290rwhp with nothing modified but no cat.

mark kibort

whats flash to pass?

MarkRobinson

Mark, similar 928's that don't have polished heads & manifold porting are making 310-315rw on Porken's chips with timed cams. I think my motor's 20-25rwhp stronger than the average stock motor because of those mods....and still had out-of-timed cams & stock 1986 chips.

MarkRobinson

My LED running lights (outer lights) have a momentary disconnect on the steering wheel for "flashing people" who you need to pass who've not noticed you coming up on them so fast

mark kibort

ahha! i see.

i didnt realize that the heads and manifold porting did that much.

i did have the same mis matched cam timing when i replaced the cams on the holbert car...correcting it gained back 10hp . (there was also a weird sound that the exhaust made... like a different flavor of a V8.... like the chevy.) anyway, thats worth about 10hp ... i forgot the mix of advance vs retard, but one was 8 degrees off and the other was near correct.

lets see that 335rwhp!!!!

when are you reporting back?

GlenL

What correction factor will you be using?

I'm going with 337 RWHP DIN.

What's the prize?

PorKen

382 is 'zero'. It may need adjusting higher or lower depending on the idle AFR/CO.

That's way off. Could be good for 10+ hp/tq...depending. FYI, first pic shows +2, not -2.


This is a safe bet with good air. Very difficult in my experience to get over 310 SAE, S3 or S4, stockish, no-cat.

S3s are tough to dyno. You must keep the air temp sensor from going over ~120F or it won't make over 300.

SeanR

Good luck on the dyno but have a question about this picture.

How worn is your cam gear, the way that belt is bow'd it makes me think they are very worn. Also, your belt is on backwards.