What's more beneficial?

[05stisilver]

What's more beneficial for usable power band for a 35r/40r?

Displacement (2.65L) or Rev Limit (8k-8.5k)?

[ryan_west06]

id like to know....

[blacksti]

ur sells a twin scroll 40r that spools 500rpm quicker then there 35r

[SnowMann]

An 8.5k rev limit would result in much more usable power band than the added .15L of displacement.

[LDadrenaline]

.15 litre displacement AND the 8.5k redline :D

[KAX]

definitely rev limit. your power band might be a similar length with either, but the rev limit would make it in high RPMs which would probably end up in a HIGHER usable power band as well.

[05stisilver]

That kit is a custom kit that was made for the big valley sti.........And from what I have read is like 10k (don't remember exactly). It's not the normal 40r kit on their site







ur sells a twin scroll 40r that spools 500rpm quicker then there 35r

[-faded-]

higher rev limit would be better

[I'm Slow]

Def rev limit. Those turbos own uptop in the rpms. For street I say 35r.....for track only then 40r

[blacksti]

That kit is a custom kit that was made for the big valley sti.........And from what I have read is like 10k (don't remember exactly). It's not the normal 40r kit on their site

i talked to them dirrectly they sell it but tis not listed on their site... they also said theyve sold it to a lot of people with street cars... its 7k for the kit but its comes with everything i was thinking about getting it when i build my bolck

[ImportImageRacing]

i agree with snowman, higher revlimit will be best. as is on my 30R with just .82 on stock dispacement my peak hp # is at redline...meaning im still gaining...everything relative..moving the powerband to the right, would make one think you'll want quite a bit more room with revs.

[05stisilver]

As far as the 40r kit goes....and if I had to do it over which is what I wanted to do....but would have lost alot of time/money on it was get one of these kits........

Full-Race Motorsports LLC Call us toll free at (866) FULL-RACE (http://www.full-race.com/catalog/product_info.php?products_id=1834&osCsid=9140386454f049b78e787ca53dbb6783)

They also have the first twinscroll 35r kit that I have seen and their 40r kit is cheaper then the UR and in my opinion its better(may not be)







i talked to them dirrectly they sell it but tis not listed on their site... they also said theyve sold it to a lot of people with street cars... its 7k for the kit but its comes with everything i was thinking about getting it when i build my bolck

[05stisilver]

I feel the same way but...........I was trying to cheat and just get a built bottom end. Do you feel that if the rev limit was only 8k if would still be the best route?

An 8.5k rev limit would result in much more usable power band than the added .15L of displacement.

Unfortunately if the rev limit is the main factor I have to do both.............bottom end and heads/cams........and I won't be able to do a 2.65L because it's not recommended to rev that high (only 7300'ish)



#6 (http://www.tamparacing.com/forums/showpost.php?p=4719297&postcount=6) (permalink (http://www.tamparacing.com/forums/subaru-tech/435546-whats-more-beneficial.html#post4719297)) KAX (http://www.tamparacing.com/forums/member.php?u=17055) vbmenu_register("postmenu_4719297", true);
Registered User

Car:
My TRGarage (http://www.tamparacing.com/forums/vbgarage.php?do=viewparked&id=17055)

http://www.tamparacing.com/forums/customavatars/avatar17055_0.gif (http://www.tamparacing.com/forums/member.php?u=17055)

Join Date: Nov 2003
Posts: 465
TRader Rating: (0 (http://www.tamparacing.com/forums/itrader.php?u=17055))
http://www.tamparacing.com/forums/styles/trnight/reputation/reputation_pos.gif: 4522

[-faded-]

hell, i wish i had longer reline with my FP green, 8.5K would have been a blast.

[homemade wrx]

a larger hotsided 35r would have a nicer torque curve unless you were to run a mid size 40r with some larger drag cams...the 35r would still have an earlier torque curve though.

the 40r setup that spools faster is also a very small a/r hotside with a twinscroll hotside...UR hasn't made a twinscroll 35r kit yet...I'm still buttoning mine up ;)

are you trying to make a drag setup or a roadcourse setup? aside from street driving, that is...

As for the shortblock, I'm doing a real long rod and comprable redline (redline being peak g's) to the EJ257s rod ratio puts me at 9200 with the same absolute acceleration rate...yes, I'm a mechanical engineer/IC engine nerd.

Don't worry, I have a few tricks I'm doing for the oiling system as well...I do have to give up a few cc's of displacement to the 257 though...I do have better discharge coefficients and quench height though...also a nicer quench pad

I'm not a fan of short rod ratios unless you are an auto-x'er or a short road course torque fanatic. Hence my questioning the purpose of the build. Pending what you want, there are most likely better shortblock options than a stroker.