Topic: high compression D 12:1 c/r as DD + boost (Read 30009 times)

turbo4life · « **on:** March 09, 2009, 03:53:53 AM »

ok i started this tread in old hmt

now here for REALhmt nigga

the motor
d16z6 block head IM all stock

pistons
pm7 what ever came in the d16a1 pistons

ARP head studs are a good idea!

fuel type
i will start off with 91 and work my way down as i want the best mpg and as my detonation detection eqipmetn gets more advanced like something electronic and automatic using some features in crome gold to do on demand retard in case case

this will be BOOSTED planning on not running more than 8 pounds

i was wondering when i get this motor running i will boost it since i want to be able to take this car on a long ass raod trip and

i want hill climbing torque! i want good mpg so why not try it

the only fear i have is what is the best way to monitor for detonation i know i cant be driving around all day with a det can in my ear

holla nogs

d112crzy · « **Reply #1 on:** March 09, 2009, 03:57:37 AM »

Get yourself an otoscope and save up some money to buy lots of spark plugs and learn to read them.

turbo4life · « **Reply #2 on:** March 09, 2009, 04:05:52 AM »

spark plugs are cheap!

9 dollars a set or ngk bkr7e every 3 k miles ill be fine

osciliscope

http://www.cwimedical.com/otoscope.html?=froogle

this will help me read the plugs intresting anyone else used this i have good vision im not sure if ill need this..

d112crzy · « **Reply #3 on:** March 09, 2009, 04:08:43 AM »

Holy shit those are expensive. Here's the one I have
http://www.drmomotoscope.com/#product

Even the best vision won't allow you to be able to look deep into the base of a spark plug. An otoscope will.

p.s. Your poll sucks. You forgot 10psi will turn ya out.

turbo4life · « **Reply #4 on:** March 09, 2009, 05:00:15 AM »

fixed

sewell94 · « **Reply #5 on:** March 09, 2009, 10:20:54 AM »

I don't see an issue with the high cr and boost. You just have to make sure your tune is right on the money. The money in this situation would be the timing.

The small bore helps to fight off denotation, thats why you seen people go threw 58 head gaskets, they'd ping the thing, and instead of straight fucking things up, the cylinder pressure would lift the head/wiggle the sleeves alittle, giving the illusions the gasket was at fault.

But i'm just a lowly noob with 2 posts, so wtf do i know

doubleA · « **Reply #6 on:** March 09, 2009, 11:07:10 AM »

sikocivic did a build like this, Small turbo at 7-8psi with high compression. Good tune= good to go.

snm95ls · « **Reply #7 on:** March 09, 2009, 11:20:54 PM »

Quote from: d112crzy on March 09, 2009, 04:08:43 AM

Holy shit those are expensive. Here's the one I have
http://www.drmomotoscope.com/#product

Even the best vision won't allow you to be able to look deep into the base of a spark plug. An otoscope will.

p.s. Your poll sucks. You forgot 10psi will turn ya out.

Sweet!!

Just ordered one for myself.

;D

trevor72 · « **Reply #8 on:** March 11, 2009, 01:10:57 PM »

yes, there is lots in reading a spark plug. What about a knock sensor? by the time it works damage may have already occurred.... if you were at say full boost under high load (hill climbing), but might be a good safety net.

Aero · « **Reply #9 on:** March 11, 2009, 03:46:05 PM »

Build a Det can. If someone else doesn't I'll try and find a link after I get off work. They work awesome.

turbo1.5 · « **Reply #10 on:** March 19, 2009, 10:35:07 PM »

It really depends on what pistons you end up getting. The oem pm7 pistons are supposed to have a 29mm compression height. If you get those, they will sit about .040" below deck on a sohc d16. But if you get 75.5mm NPR p29 pistons like I did you'll end up wih this. This is a y7 block.

Here's a comparison of a oem pm7 piston pulled straight from a d16a1 compared to a NPR p29...

If you have real pm7 pistons boost that thing, if not stay all motor and enjoy the 13+ compression ratio! Should be a fun motor either way

crttaz · « **Reply #11 on:** March 19, 2009, 11:39:25 PM »

Glad I didn't get those NPR's, my P29's are already sitting .052" out of the deck at the edge, almost .200" at the dome.

92CXyD · « **Reply #12 on:** March 20, 2009, 09:58:44 AM »

could you just take the NPR pistons to a machine shop and shave a few .001 of the dome to make it more comfortable because I'm thinking you have very little piston to valve clearance, if any clearance.

Ravage70 · « **Reply #13 on:** March 20, 2009, 10:56:45 AM »

ROFL HILL CLIMBING TORQUE

Compression doesn't give you that much more power. It just ends up fucking you in the end.

turbo4life · « **Reply #14 on:** March 26, 2009, 12:30:38 PM »

i have oem pm7 and ill be using them in a z6 block so far i found on the interwebs they will sit .040 below the deck and give me about 12.1:1 cr

i would like to run ls rods any one have any idea if its possible to use these pistons in a full floating forum if i cut a groove for a snap ring in the piston to hold the wrist pin. and put silicone bronze bushing into ls rod

Joseph Davis · « **Reply #15 on:** March 28, 2009, 10:34:27 AM »

The small bore encourages detonation. Stock compression D16 are too high a CR.

If you do this, treat it like a shot of nitrous and make sure the boost doesn't hit until 3500+. Keep boost low as power/psi will be elevated due to CR, and I don't trust witches' brew labeled 93 much less your 91.

turbo4life · « **Reply #16 on:** March 28, 2009, 01:38:00 PM »

got that and ill just be using the stock D rods and i want to only run 5 psi and no boost before 3k and small bore in creases detonation .. i knew i heard jd say that one before

well any way i put together a bin file im thinking of startin to run the engine

i only messed with the mapping

retared timing accross the bord by 7 deg then added 2.25 deg/psi timing retard

120% fuel
375cc accels (thanks 97 econo box)

JD what should i do in the advanced settings add higher value to iat retarx and cht fuel corrections?

im thinking of running it nice and rich for safty since that helps fight off detonation

i want to start off on premium gas then go down in octane with a det can

chime in nogs

Joseph Davis · « **Reply #17 on:** March 28, 2009, 02:31:34 PM »

Your first problem is going to be pingies below 1500-2000 rpms. I dialed my distributor back to get more than 6 degrees ATDC, worked well for me. Your next problem is going to be pingies at transition to boost, depending on how close to 3-3500 it hits, and how hard it hits. After that I have no doubt that you can pull it off. 5 psi with that CR should net you a lot more than your average turbo D16, expect 180+. In the higher rpms it'll be like a mundane tune, only you'll want to run less timing.

If you can afford a cam I'd run one as the extra overlap will do away with a lot of the low rpm volatility, but that starts getting pricey for a stock rod build.

I believe my distributor is retarded 9 degrees, so subtract that from the values displayed below. Also remember I have an HX cam, it might be a little different in the low cam area, but high cam is probably within ~2 degrees of where you'll be:

turbo4life · « **Reply #18 on:** March 31, 2009, 05:14:22 PM »

wow thanks jd btw i do have a hx cam and rocker assembly!! i think ill just go your route drop the hx stuff in there and roll!!

so your running 87 octane ? a

and what afr in boost do you aim for .. i m thinking of makin it rich for safety like 11 10.5

d112crzy · « **Reply #19 on:** April 06, 2009, 11:46:26 PM »

11's flat would be overkill, IMO. You're gonna be losing some power at that point. I'd say aim for mid 11's to be on the safe side and add some cooling effect as well. Just don't go crazy on the timing and you'll be fine.

News:

Poll

this high 12to 1 d

Author Topic: high compression D 12:1 c/r as DD + boost (Read 30009 times)