i know you all have seen countless threads on this but i am looking for ideas on my specific build ideas.

as soon as i sell my RB25 S13 240sx, i will be building a motor for my goat since it is kind of the last frontier for me. i have done everything else to a car that you can think of except actually building a motor for one.

my idea/parts list is as follows.

brand new lq4/9 block from GMPP (great deal i found $711) bored .030" over
TSP 408 balanced rotating assembly
PRC 237 or TF 235 heads (possibly 245?)
1-7/8" headers
Huge cam 25x/25x .610/.610 112LSA range?
might switch over to LS3 style heads so i can use FAST 102 and the LS3's TB
and then get the misc. stuff like new timing cover (gen IV style), get the holes drilled and tapped for the knock sensors and alt. bracket, dbl roller timing chain, blah blah blah

will be looking for 530+ wheel (really 550+ but for the sake of reasonable numbers.....)

i will be building the motor from scratch so my goat wont have any down time. current mods are 236/238 .601/.605 112 cam, Ported I/TB, pacesetter LT's, 423/385 wheel

i want to throw an F1A procharger on the car but my block now will barely hold that. i dont want a D1 because i dont want to buy the smae thing twice. i would build this motor for boost but i also would not have the money to boost it right away so that is why i am looking at the n/a route so i can have fun with the car until i get to a point where i can throw 12k around for a nasty boosted setup. plus i will have all the know how on building a motor when that comes around!

what are youre guys' ideas on my build? will 245's be too big for what i am doing? is my cam idea within reason? what CR on 93 pump gas? i see mixes of people saying 11.3:1 to 12:1 on pump gas. i realize you have to have damn near perfect gas at 12:1.

CI with 408 seems to be very safe and powerful so i dont see the reason for going much bigger especially with this block.

i will also have the ability to tune my own car with HPTuners. I am in the middle of establishing myself now as a tuner.

I have a very good idea on what i need to do, just woule like a second opinion. all thoughts are welcome.

thanks,
derek

 

so is no one interested in answering this or do i just have my **** together? lol

 

my build is considerably more tame (other than fuel) than you are talking about and i made 523rwhp with a 6 speed

11.3:1 403LS2
LandSpeed ported L92s/LS3 intake manifold/LS2 TB (same as LS3? not sure)
234/242 .598/.592 114
kooks 1 7/8 into stock catback
vararam
UDP
e85 tune

i know nothing about what cams work for cathedral heads, but you dont have to go crazy huge with your choice if you choose L92s.

 

Wow! That is pretty stout! Great numbers. What did your torque look like with that cam? Also how much timing were you running? I will be running on 93 octane on my setup

 

I think my tq peaked at 476 but it was over 400 for almost the entire rev range. I will have to check when I get home

edit: graph


dont remember any timing values, sorry

 

wow man! that is kickass! 400 ft lb at 2700 rpm!

solid numbers man! thanks for the graph, i believe i am headed in the right direction.

what is making your AFR's go all over the place?

 

thanks, i was pretty happy with the outcome. she chunked a timing chain back in october so the rebuild is in progress. revised exhaust porting and a step up to 1.600" exhaust valve (from 1.590") along with a thinner gasket to take me to 11.7:1 compression and a retune... im shooting for 550 this spring (pretty ambitious... but oh well, haha)

AFRs on the graph were the readings from the dyno's wideband. my tuner had his own wideband plugged into a bung in the header and was tuning off that

 

ahh :/ sorry to hear about the timing chain. was it a dbl or standard? you can never be too ambitious with your power goals lol just willing to accept what they really are with teh dyno reads it out. although, from what i am reading you have a pretty decent chance of touching that!

good luck man! ill be looking for a build thread!