intekragsr

How drastic will a 84mm bore compare to a 81mm bore regarding spool time?

Turbo is a t3/to4e .57 trim, .63 ar S3 wheel.
gsr motor.

Simple question.

THANKS!

romeo619romeo

prolly not much of a big difference...

intekragsr

:/ really? Damn. Any technical explanations?

romeo619romeo

im saing that becuz a 57 trim and 63 ar isnt that hard to spool...maybe its jsut me.. but when are you expecting for your full boost? is the real question..

intekragsr

the thing is I dont know how much boost I want to run. All I want is 350 to the wheels if thats possible on 91 octane. The motor will have 10:1 compression.

I guess my real question is how much of a difference will 2 liter make over 1.8.

tony1

Quite a noticable difference. Sorry i don't have any real numbers for you though. I've built and driven both setups and it's worth it to go bigger bore!

falcongsr

let me guess...bigger bore = more displacement = more exhaust gases = higher manifold pressure = quicker spool?

do i get a cookie?

tony1

No, but you sure do deserve one!

intekragsr

haha well of course I know that.

What I am looking for though are kinda rough numbers. Am I going to see hp number increase drastically as in another 20 hp, or just like 5 more per psi.

Also would the spool time be like 100 rpm quicker or like 1000 rpm quicker.

Thats all.

Heres a smiley cookie

Full-Race Geoff

it makes a difference. I am at stock bore, and a buddy has the identical turbo setup as me... his car can get out of its own way at 1700 rpm, mine takes its time to about 2300-2500

Ray

wow it starts boosting @1700RPM? What turbo is this?

romeo619romeo

57 trim 63 ar stage 3 wheel

Ray

hmm somine will be around 1700rpm also? maybe I should get a bigger turbo

intekragsr

1700 rpm?

damn thats like stock turbo territory!

symba

so, on my prelude h23 87mm stock bore, JE 10:1 pistons; I can expect spool at around 1700 rpm with a t3/t4e .63a/r turbine 60trim compressor? That is like stock turbo spool up. I didn't think it would come that early. Plus I'll be running with a 3" exhaust.

Full-Race Geoff

60-1 ball bearing t3t4 with our turbo kit on a sleeved b20vtec.

intekragsr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FFgeoff &raquo;</TD></TR><TR><TD CLASS="quote">60-1 ball bearing t3t4 with our turbo kit on a sleeved b20vtec.</TD></TR></TABLE>

Of course ball bearing and the famous FR mani

I want a bigger turbo now too. Im not sure I need bigger since my only goal is 350-400 whp. Im not as crazy as some of you other guys.

onetwothree

https://honda-tech.com/zerothread?id=543984 It's just something I enjoyed reading.

symba

60-1, huh?
That sounds sweet except I have NO money to upgrade my turbo. Hell, its still sitting in the box wrapped in plastic....Maybe down the road after I actually can feel what it's like to drive a turbo Honda.

intekragsr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by onetwothree &raquo;</TD></TR><TR><TD CLASS="quote">https://honda-tech.com/zerothread?id=543984 It's just something I enjoyed reading. </TD></TR></TABLE>

Good thread. I coudlnt find it searching because it didnt have 84.5mm in the title
Thanks

Full-Race Geoff

no need for a bigger turbo, just use the one you have to its fullest potential. A lot of people get caught up in getting a bigger and bigger turbo and there is really no benefit.

Keep the turbo you have until you turn the boost up and it stops making power. Once you are at that point then it is time to consider a new turbo

onetwothree

FFgeoff I was looking for that turbo you had posted to show my friend because I wanted him to buy it. But you "poofed" it. What's up?

symba

That makes me feel better, thanks...

You could have easily sold me on getting a larger turbo. I appreciate your honesty and knowledge.

Full-Race Geoff

i decided not to advertise for it on here, they are still available but on backorder right now. We got a number of orders very quickly for them. It is a very good turbo.

if you need more info email me, geoff@full-race.com

Boostfed

This is what I posted in another thread, real world #s and our experiences.


"OK real world dyno numbers from a friend of mine on his B18C Darton block, he went with 81.5mm bore for the same reasons mentioned above in case of damage he can still go up to 83,84,84.5mm etc. Well he did have a problem tested how far he could go on 116octane somewhat High compression 10.5:1 until a piston melted and there was damage to the cylinder wall, a simple .5mm overbore or even 83mm was not fixing the walls on this block so he went 84.5mm because he had too. Well here are #s 81.5mm 18psi=489whp and 84.5mm 18psi=506whp no other changes except he did lower the compression by .2-.3 CR so 10.2:1. When he went to 25-26psi on the 81.5mm bore made 591whp! Advantages of the bigger bore are of course more displacement and more torque, every little advantage you can get. Also the valve reliefs on the pistons can become more optimal instead of being at the very edge, unshrouding the valves and opening up the combustion chamber etc etc while keeping a good R/S ratio instead of going longer stroke and shorter rod, not talking about deckplated motors here though.
I myself have a B16A and I can use all the extra diplacement and help possible, I originallt went 84.5mm GE block that they bored and the tolerances were real loose looser than the Piston manufacturers specs but they were useable, after the sleeves sunk I had no choice but to go to 85mm but the sleeves sunk again! I now have a Darton sleeved block staring at 84mm so I still have room to play with as long as no MAJOR damage occurred. B16A needs all the displacement possible due to the short stroke which equates to less torque. so again

81.5mm 18psi=489whp
84.5mm 18psi=506whp also with .2-.3 lower compression "