Pistons, pistons, pistons

[therieldeal]

you should not have been making 200 hp/torque on stock boost.

either it was creeping like a mo-fo, or your ignition was advanced way too far and you were making that power at the verge of detonation. i'm thinking both.

[roymacavoy]

dont really know what to say on that one, got the dyno sheet. I have a boost gauge and it was running at the stock internal wastegate. I am gonna go with the verge of detonation, but for almost 3 years and 30,000 miles? Must have been one hella strong engine.

[therieldeal]

i dunno... its just that most people with their ignition set up to stock settings need close to 15psi to get numbers like that. at stock boost people have done 160ish whp

what kind of dyno was it?

[roymacavoy]

it was one of those portable ones, dynojet research, dynotune speed and performance. paid 75 for 2 pulls, did one in 3rd and one in 4th.

On another note, if that is true, that sucks. I hope I dont notice a 40hp drop with this other engine.

Same dyno as wheresthericego.... so should be close to acurate.

[roymacavoy]

took a look at the spare engine today, removed the head and inspected the block, Sending it out for a cleaning and honing, purchased some gtx rods and gonna talk to machine shop about piston size. thinking about some gtx injecotrs, do I need a resistor to run them? I seen the seller recommending one. Got the mazda oem head gasket and if someone could help me out with the part # to some arp head bolts and rod bolts that would be great.

[therieldeal]

the arp bolts will be listed for the 94-97 miata

did you mean GTR injectors? if so, yes you will need a resistor box. you will also need something to control them, such as a SAFC

[roymacavoy]

do you know where can I get a resistor for them? MS is what I am planning on using for engine managment, I already have it, just need a few things for it ie... TB from auto gt and some other odds and ends.

[therieldeal]

oh, megasquirt (2 at least, idk about 1) can control lo-z injectors directly. read up on it though, you have to do some additional grounding and you may need to route the power supply for the injector driver seperately. i was getting flyback voltage spikes with gtr injectors on a standard MS2

[roymacavoy]

Thats nice to know, I will have to talk with jacob, thats who I got the ms through.

[stylingtwagon]

where do u find the 9.1 cr pistons at and how much are they can u just run hyperectecic pistons ?

[13thghost]

can you install small capacitors to help with the fly back?

[therieldeal]

that was one of the reccomendations that i found.. you isolate the power supply for the injector driver with a capacitor. i never really got into altering the wiring inside the MS... i just switched to (bigger) hi-z injectors.

[323driver]

The 9:1 pistons are only available through Flyinmiata, I believe. The other ones, the 8.6:1 are standare wisecos and are available in 0.02" over and higher.

[mazstar]

heres some helpful info if u wanna go to gtr injectors and cant be stuffed playing round with your m/s u can use a honda prelude resisor pack thats what the guys over here do when switching to low impedence

[jrally]

There are plenty of cars in salvage yards with the resistor packs for low-imp injectors. They are usually mounted on the firewall, or next to a coil on older cars. I see them on older Toyotas all the time.

-Jon R.