Engine Theory, Build, Etc Discussion.

pyaarawala

Well-Known Member
Joined
Jul 1, 2007
Posts
4,087
Reaction score
2
Location
long island, NY
I'm a n00b at this stuff to so I just have a question:

When you state compression, you state it in this format, XX:XX:XX. What do each sections mean? My car (F23a4) comes stock 9.3:1 according to the 6thgen general FAQ. Why is it that the lower the compression, the better? And by lower, you mean that it goes from 9:3:1 to 8:3:1 or something? Also, you said that increasing the combustion chamber, and lowering compression makes the car faster. How does the combustion chamber increase if the cylinder can not expand?

Also, what's boring and sleeving?
 

I4 CG5

Well-Known Member
Joined
Sep 25, 2007
Posts
766
Reaction score
3
Location
Fargo, ND
^^You want lower compression if you have a turbo and higher compression if your engine is N/A
 
Last edited:

BadgerType

Resident ***hole
Joined
Dec 16, 2005
Posts
9,037
Reaction score
46
Location
SW FLA
question for our Engine God, Greg

How much hp is gained when switching to a dry sump system?

how much boost can our stock sleeves hold? as in actual test, not speculation

what engine break-in practice do you recommend for a newly built engine?

Do you recommend lightening the crank for mid-high boost applications?

Sythenic or sythentic blend oil for our engines?

best way to raise the rev limiter?

i shall have more for you greg
 

xci.ed6

Well-Known Member
Joined
Sep 5, 2007
Posts
2,909
Reaction score
9
Location
Tampa Bay
I'm a n00b at this stuff to so I just have a question:

When you state compression, you state it in this format, XX:XX:XX. What do each sections mean? My car (F23a4) comes stock 9.3:1 according to the 6thgen general FAQ. Why is it that the lower the compression, the better? And by lower, you mean that it goes from 9:3:1 to 8:3:1 or something? Also, you said that increasing the combustion chamber, and lowering compression makes the car faster. How does the combustion chamber increase if the cylinder can not expand?

Also, what's boring and sleeving?

you mean, xx.xx : 1

higher number = higher compression, higher cylinder pressure before ignition
lower number = opposite

ex: 6.0:1 the volume of the combustion chamber at BDC is 6x the volume at TDC, etc...
 

xci.ed6

Well-Known Member
Joined
Sep 5, 2007
Posts
2,909
Reaction score
9
Location
Tampa Bay
How much hp is gained when switching to a dry sump system?
too many factors involved for something thatno one in their right mind does

how much boost can our stock sleeves hold? as in actual test, not speculation
there is no answer to that question. boost has little to do with the factors that cause sleeve failure

what engine break-in practice do you recommend for a newly built engine?
drive it how you will be driving it

Do you recommend lightening the crank for mid-high boost applications?
less weight is always better

Sythenic or sythentic blend oil for our engines?
synthetic is always better

best way to raise the rev limiter?
reprogram ecm, but by the time the engine is ready for the rev-limiter to be raised, it probably also needs more than a piggy-back should be doing
 

Roadrage

Well-Known Member
Joined
Jan 15, 2007
Posts
918
Reaction score
0
Location
POPE AFB/ FT. BRAGG
okay question for greg,

How many teeth does our camgear have, For an A5, tried google got two different numbers, one says 40 and another says 37, hopefully u can help. thanks in advance
 
Last edited:

BlkCurrantKord

Super Moderator
Joined
Sep 7, 2005
Posts
9,870
Reaction score
85
Location
Ohio
LoL - stop asking me specifically.

No idea how many teeth our cam gear has. The best I could do for you is count my Skunk2 cam gear.
 

BadgerType

Resident ***hole
Joined
Dec 16, 2005
Posts
9,037
Reaction score
46
Location
SW FLA
How much hp is gained when switching to a dry sump system?
too many factors involved for something thatno one in their right mind does

usually 8% increase through tires

how much boost can our stock sleeves hold? as in actual test, not speculation
there is no answer to that question. boost has little to do with the factors that cause sleeve failure

boost has alot of factors with our sleeves. i think it is 32lbs

what engine break-in practice do you recommend for a newly built engine?
drive it how you will be driving it

it was a new age (hard) or old age (easy) break in question. i plan on doin the new age break in

Do you recommend lightening the crank for mid-high boost applications?
less weight is always better

tru, but so many factors can cause the engine to fail, i wanted to hear his view

Sythenic or sythentic blend oil for our engines?
synthetic is always better

yeah, i ran out of questions

best way to raise the rev limiter?
reprogram ecm, but by the time the engine is ready for the rev-limiter to be raised, it probably also needs more than a piggy-back should be doing

im not talkin removing the rev limiter, but raise the redline so i can safley run 8k every shift

.
 
Back
Top