stuck with 10.5:1 pistons

[jason_guy_yeah]

For my eventual turboed b18b, I already have eagle beams and pistons. My WHP goal is 400 but, how do I turbo size right with high cp?

 

[jason_guy_yeah]

With 9:1 cp pistons, I would use a say...T61. But, with 10.5:1 cp pistons, what size turbo do I use?

bump

 

[MrRide2Low]

no turbo, size doesn't matter to your compression, 10.5:1 is to much for boost, sure i can work but it's not that safe, i'm not saying you can't do it but you will have alot of knock, we boosted a jdm gsr at 10.6:1 and end endresults were 2 holes in the block, didn't make it even 2 hours before it boost spiked and rapidly dissasembled it's self on the road to the dyno. in other word's just bit the bullet and drop your compression ratio with some different pistons or you prolly won't like the small amount of boosty that your kinda limited to

 

[Kaotic_Zeus]

i would never recomend boosting anything with 10:5:1 or higher CR, unless you lower it.

 

[jason_guy_yeah]

crap this sucks, any other ideas?

 

[Steven.]

sell the 10.5:1 pistons for lower ones

 

[got traction]

^^ x2

 

[jason_guy_yeah]

Although I've got high CP, I need help turbo sizing. So far I've found that a GT4038 or T61 works (b18a)but, would I lower the displacement factor?

 

[Steven.]

damn, those are big turbos, whats this for? street? drag? those are really big for 400hp, a GT30 should be suffciant

 

[jason_guy_yeah]

Well, I've been using:

http://www.squirrelpf.com/turbocalc/index.php?target_peak_power=400&engine_disp=109&target_af=12&bfsc=0.60&max_ic_loss=1.7&rpm_redline=6800&rpm_peak_power=6800&rpm_max_boost=6800&rpm_min_boost=4000&vol_1=99&vol_2=99&vol_3=99&vol_4=99&intemp_1=90&intemp_2=130&intemp_3=130&intemp_4=130&pre_company_id=1&pre_family_id=2&calc=yes&company=1&family=2&product=6
as a reference, and I compared it to doing the calculations myself and they seem accurate.

If these are wrong, can you give me the right turbo sizing equations.

edit:actualy I plotted the GT3076R and it fits right in.

 

[Steven.]

i recommend go buy teh book "maximum Boost" by corky bell.

that will help you in sizing the turbo.

 

[jason_guy_yeah]

i recommend go buy teh book "maximum Boost" by corky bell.

that will help you in sizing the turbo.

will do

 

[nurevEKcivic00]

put in a thicker head gasket/ maybe even double stack em to lower your compression

 

[stealthy]

sell those pistons and buy my je 9:1's

http://www.clubcivic.com/board/fs-je-9-1-t126524.html?t=126524

 

[jason_guy_yeah]

Ok, waiting for the book but, in the mean time; I need help on this:

http://www.squirrelpf.com/turbocalc/index.php?version=4&target_peak_power=420&engine_disp=1.8&engine_disp_factor=0&target_af=12&bfsc=0.60&max_ic_loss=2&rpm_redline=6800&rpm_peak_power=6300&rpm_max_boost=6800&rpm_min_boost=4000&vol_1=92&vol_2=92&vol_3=92&vol_4=92&vol_1=92&vol_2=92&vol_3=92&vol_4=92&intake_temp_1=90&intake_temp_2=120&intake_temp_3=135&intake_temp_4=140&map_sel0=38&map_sel1=58

 

[schutzracing]

boost it and see what happens.. o tape it soo we can watch.. maybe it will work out good on low boost.. who knows..

 

[jason_guy_yeah]

On low boost I know it'll be alright, It's finding the right turbo and the 400whp goal is the problem. But, I'll tape the dyno...when I get there eventualy (months from now).

 

[majorahole]

mr. gasket has layer-able gaskets to lower compression. check out those.
you can boost it with the 10.5, but you need to have a perfect tune. even then its iffy

 

[juan2k2001]

10,5.1 is not bad just build right get it balanced to perfect spec...good oil pump...ACL bearings and a good tune and you be good..My boy LS did 545whp with the same thing..Just sleeved..545whp aint no game....

 

[Blazed]

10.5 is not that high a compression..just get a good tuner..

and even if u have to go with a smaller turbo which is just not true..u will make more power on less psi with higher comp than u woudl with lower comp...