SimonsTeg

eventhough i still consider myself a newbie compared to the majority of the members on this board, i've done a ton of reading and research and i thought of a possible setup that i may end up going towards.

ls/vtec setup:
stock b16a head
b16a intake manifold
'91 ls block
pr3 pistons
shot-peened rods
arp rod bolts
about 11.3 compression

custom turbo setup:
14b, t25, or t3 turbo
fmic or smic- possibly mounted on the front
dsm 450 injectors
walboro in-tank pump
s-afc or v-afc
the usual ex. manifold, downpipe, piping, bov
boosting 10lbs.

i thought of the set-up because a vtec turbo setup seems to be the best. the ls/vtec setup should be able to keep up with the rather stock GSR's. from what i've read over the past 6 months, 10lbs. of boost on an LS engine can possible run 13's, having vtec allows a higher rev-limit to stay in boost longer, the higher compression allows for a faster spool and more power then keeping the stock 9.2 compression and upping the boost to about 13 or 14lbs. as for he rest, i'll keep the longer geared LS tranny and won't rev any higher than about 7k RPM.
so how does this set-up sound? i know it's not perfect but so far, it sounds ok.

Pelican

why wouldn't you rev higher than 7K? Eh, the B16 head flows a lot better than the LS and even though the rod ratio isn't b16-esque, you should be able to go to at least 8000 on a stock valvetrain.

HybridKOOP

11.3 compression + n00b + boost = blown motor.

Pelican

Good point. That high a CR might need a little more tunability than the VAFC hack. and with the smaller turbos, spooling won't be as difficult as you think.

SimonsTeg

thanx for the replies so far. first off, the reason i wouldn't wanna rev higher than 7k eventhough i know i should be able to is the exact reason that was given:
higher compression plus a newbie plus boost.

i wasn't worried about the valvetrain seeing as how the head would be a b16a which handles 8k, i was worried more about the block. i figured it'd be safer to keep the revs at around the stock LS levels while having the bottom end a little stonger with the shotpeened rods and ARP rod bolts.

i've read that the weakest part of the engine was the rods and rod bolts so i figured i'd strengthen the weakest parts. people have said that they've been able to keep their engines stock but run them as if the block was built up.

but yeah, the reason for the 7k RPM limit is because i thought it'd be a lot safer with having a higher compression and boost. but then again, i could keep the stock 9.2 compression and go ahead and rev up to 8k. that doesn't sound too bad either but still sounds as risky to me.

HybridKOOP

You'd be 10x safer running the motor to 8000rpm at 9.2:1 than spinning it to 7000rpm at [B]11.3:1.

Doodoo

Don't short yourself on the rods. I did the same thing and am still kicking myself. I didn't blow any of the rods away but after boosting awhile I wanted more boost and the rods held me back. Get some Eagles, $360 is cheap for a strong, proven rod.

X2BOARD

11.3:1 + BOOST = KABOOM !!! Exactly how much reading have you done ? You don't seem to have learned much... I call BS on the claim of reading.... Kill: Your motor

11.3:1 and 10psi is not possible with the afc hack... and even with some type of engine management, if the humidity were to decrease... KaBOoM... well maybe not literally, but you get the point. Higher CR doesn't have much to do with higher RPM, but if you plan to boost on high CR... those stocker rods will be a waste... stock rods are for low boost or mid HP all motor setups ! (IMO)

Get better rods if you're gonna do this... balance everything, 9.5:1 CR pistons... (for HIGH CR) and a t25 turbo and roll out with about 200whp at relatively low boost... that way you can still use the afc hack and not shell out the bread for an engine management.

X2

SimonsTeg

i've been doing quite a bit of reading actually. but when it came to compression and boost, there wasn't much out there to research. from what i've read, the only thing mentioned about compression and boost is that the lower the compression the more boost that can be ran, but a higher compression, eventhough means lower boost, can produce more power and spool the turbo quicker. as far as safe boost levels for a set compression, i didn't find anything. that's why i posted the setup to see what you guys thought and now i know.

now i'm starting to consider just choosing between ls/vtec or boosting cus if i do both, i gotta tee off an oil line twice... one for the vtec and one for the turbo. turbo sounds a lot more tempting seeing as how 10lbs. of boost should put me at about the 200whp mark (even with a sorry @ss t25) and i can still use the afc hack.

thanx for all the input.

racecarpete

give the guy some credit guys. With his few amount of posts they have been pretty good posts. Not any "what is the best turbo" and "how can i make 500 hp daily driven posts". By the looks of things he has done some research. He is just trying to clear up the few gaps that he hasn't found information on yet.

Anyways don't worry about the teeing business it is no big deal as long as you run a line to the firewall and tee it there you have nothing to worry about. If you do the double tee on the block you risk it snapping off under harsh driving conditions.
And what all the others posting about the compression ratio is right, yes you can make more power with a higher compression ratio but you have way less room for error and I would recommend a little bit of experience tuning that high compression ratio. From the looks of it you are looking to tune this setup yourself so to be on the safe side run the lower compression.