mxman

iTrader: (1)

2004 lq4
XER273 cam (224 230 581 588 114) around 49 degrees overlap
tsp stage 1 ported 799s (same as 243) with hand polished comb chambers decked a bit (62cc)
mr gasket .051xx head gaskets
28.8's

FC rx7, gets pretty warm, usually around 200-210f say on highway tuning iat around 100-120 (i'm sure it gets hotter heatsoaking when i'm sitting around)

stock exhaust manis blah blah

Anyways, in HP tuners on 91 shell vpower (best non eth gas here) I was getting pinging, spark table was around 28 degrees, it was around 30 32 ish in the .4x to .5x areas and 41 around .008 g/cyl in hptuners..
BTW I set the table for 25 degrees or so and ran e10 (supposedly 94 octane) through it and the pinging subsided mostly..

I didn't find the ignition map too aggresive, but am i missing something? I thought my CR woudl be around 10.6 is it really like 11:1 or something?!

Thanks in advance, if this the wrong forum lmk where I should post it!

mark21742

What pistons are you running ( dishes, flat, cc valve relief), what length rods and what is yours intake valve closing point?

A.R. Shale Targa

iTrader: (2)

You are about 10.6 but with a small cam and good cylinder pressure it may
be octane sensitive with higher than stock timing. Also the manis are holding
heat at the cylinder head. My 03 Silverado SS had only 21 deg timing stock
with 10 to one comp. Those cumbustion chambers are pretty efficient and
since yours are polished it may only need 24 to work fine with the fuel thats
available in your area.

Sales2@Texas-speed

iTrader: (5)

Agreed, your static compression ratio isn't crazy at just about 10.6:1, but you've got some crazy restrictive manifolds on there that aren't helping! The relatively small camshaft (without knowing the ICL) has a relatively early IVC event, which also is going to make it a bit sensitive, particularly if you've got some advance ground into it (110 ICL or so).

mxman

iTrader: (1)

I really do appreciate the quick replies.

The ICL on the xer-273hr14 is 112

valve events are :
intake opens 25 deg, closes 69 deg
exhaust opens 76 deg, closes 24 deg

I bought a set of mac midlengths I intend to modify (rx7+4l60e have no off the shelf solution, just have to clock them to clear the steering..) I'm just waiting for them to ship(canadian postal strike) oh, and yes, i'm slicing off the raspy collectors, lol!

Another quick Q, if I run 91 and say 23 degrees timing, and get no pinging... would it potentially have a higher HP output than 25 degrees and E10 "94 octane" fuel? I know the btu output of non ethanol blends is higher...

What IAT should I be around? I might be able to make a straight flowing cold air inlet setup for the car, currently i'm running a filter with an ugly 90 degree bend in it (i know) I guess the big thing is, when does the IAT substantially affect pinging? I'm sure it's heat soaking to around 125-140 at the track when it's hot out..

Thanks again, I will probably not have any updates until I put the headers on, eh? Thanks!

A.R. Shale Targa

iTrader: (2)

I'd bet your engine would love the TSP 233/239 cam to relieve a little
cranking compression (less timing sensitive)

mxman

iTrader: (1)

I've been reading with 10.5:1 guys run around 22-24 degrees timing, i'm thinking of running a cold air intake, is it true ls1's gain power from having the air come straight into the intake manifold? i hear 90 degree bends can be restrictive?