Reliable pwr

[ice57l]

hi, just wondering everyones thoughts on going the next step. at the moment i have a vx ss with 140000km on the clock. it has a cam and tune with all the other bolt on, it makes 272rwkw. i know i need heads and a bit more comp to hit the 300 to 310 rwkws but will it be reliable? or is it best to leave it at 272 and just freshen the rings and bearing or should i go for more???

[SirNemesis]

Shouldn't be any more unreliable by doing the heads. I wouldn't bother even looking at the rings or bearings unless you already suspect a problem.

[ice57l]

well the rear plate is leaking . so i was going to pull the motor out and clean it up, clean up a few things in the bay , move the ecu and relocated the coils. its not the price or that i cant do it, but i dont want to do the heads, up the comp, retune , and then find out S@#t its a pig in taffic,, im prob more asking do they still run ok making that pwr??? ive seen posts that say that make heaps more torque,, if anybodys makeing that pwr n/a id like to hear your thoughts... if its going to be a big problem then ill just pull it out and check it all, clean it then drive it simple...

[VXSS5702]

You might be lucky and get 300rwkw but I doubt you will see 310rwkw from a n/a LS1. If you go for a really wild power cam you might see it but it would be a real dog on the street. 272rwkw is a really good number. What torque figure does it make? Sonny did mine up in stages. It made just over 262rwkw with OTR, cam, rods and valve springs, cat back and diff gears. Then moded a bigger TB, Higgins heads, Di Fillipo headers, roller rockers, new rods, clutch, rip shift and power went up to about 290wrkw. last of all did a fast inlet manifold and power stayed about the same. Torque is really good though at just over 740Nm. It's bullet proof. How much power do you want and how much cash have you got to spend?

[feistl]

I doubt you will see 310rwkw from a n/a LS1.

well in 346ci form anyway.

What else has been done to the car? Diff gears will make a pretty noticeable difference in day to day driving. There are options for more power but it all adds cost, do you want more power?

[ice57l]

thanks, it has the 25% underdrive pulley, x force 4into 1's, lighten flywheel, 100 cal 3inch cats and down to a 2.5 inch hurricane system, the cam is a crow cam 226 231 dur 550 lift. and the rest was std 14000km ls1 and if im reading right it made 560nm but it was over 550 from 3800 to 5400. since then ive gone to 3.9's and have a ported throttle body on it, ive heard that the ls6 manifold is good and keep it , just port it alittle. ive also heard the fuel system will be ok till over 300, also worry bout my yella terra otr as the car go's harder if you just take it off and run nothing! ??? might need a bigger one. but is it worth the $$$ for those 28 kws , seems it in the torque figures

[255-LS1]

what do you need more power for?

with 140000 on the car id look at servicing other parts such as suspension, brakes, diff, etc if you haven't already as they will be worn.

IMO heads wont hurt your engine at those Kms provided its been well looked after. what may hurt it is you continuing to thrash the fuk out of it cos of your new found power and torque from the heads haha

Go some heads and new lifters and you will have a solid combo...

then the bottom end will go bust cos murphy said so haha.

good luck with it mate.

[VXSS5702]

What about taking all your good go bits and sticking them in a L98? That might get you closer to the 300rwkw mark you are looking for. It might be cheaper in the long run to go that track as it appears that L98's (6.0L) tend to make more power that LS1's (5.7L) with the same mods performed to each motor. Do you want to stay with the 5.7L LS1?

[feistl]

What about taking all your good go bits and sticking them in a L98? That might get you closer to the 300rwkw mark you are looking for. It might be cheaper in the long run to go that track as it appears that L98's (6.0L) tend to make more power that LS1's (5.7L) with the same mods performed to each motor. Do you want to stay with the 5.7L LS1?

A L98 conversion when done is around $15k+. (ask the people who've actually done it).

The "bang for buck" option these days seems to be to bolt a stroker bottom end to do. Apparently the 6L block bottom end can be picked up for a few grand (including pistons etc) and uses everything from the LS1 (So you dont need to change wiring, looms, insurance or Vicroads/RTA other than an engine number change).

Its probably the most straight forward upgrade. To the OP, search for the "ls1 stroker" thread.

Cheers

[ova400]

doing heads won't make it any less drivable, in fact it should improve the drivability across the entire range. I don't think you will get 300rwkw with that cam and heads though but it will still be an improvement even if only a relatively small power gain overall.

don't get set on reaching 300rwkw, there are many better things in life than just having a car with 300rwkw, plus it would probably require a different cam which could adversely affect its drivability

[ice57l]

id rather stay with the 5.7 ... so the plates match.. .. i may just pull it out, put new rings and bearings in it, new gaskets port the heads and raise the comp then get it run on the dyno,, ill be pissed if it stops at 298 or something, the suspenion has all been done, so has the diff, and all other worn parts.. now just have to get the ac working and itll be spot on.. even just put new 20inch rims on it! ill post some pics when i get a chance... would love that 300 but ... will cost me very little to do this..

[VXSS5702]

id rather stay with the 5.7 ... so the plates match.. .. .. even just put new 20inch rims on it! ill post some pics when i get a chance... would love that 300 but ... will cost me very little to do this..

With 20" rims forget getting anywhere near 300rwkw. There are plenty of threads re power loss and rim size. My 290rwkw dropped since Sonny dynoed because I went from 17" standard rims to 19" HSV rims. You could be down 15rwkw with the 20" already. Forget achieveing anything near 300rwkw.

[AF20NC]

Just put a blue bottle in the boot and be done with it :nos:

[ice57l]

hahaha .. you know me its too easy..:flipoff:. ive heard that about 20's and also aout 3.9's , just cant understand why??? if your telling the dyno it has 3.9 and the 20's are the same rolling dia as the 17's with 255 on them wouldnt it be the same... ive been told why before but can not remember...

[VXSS5702]

The inertia of the larger diameter rims is higher than the inertia of smaller rims. If the rolling diameter of the two wheel/tyre combinations are basically the same and the engine torque is the same, then the result will be that the wheels will be accelerated more slowly and so the power is reduced.

[AF20NC]

hahaha .. you know me its too easy..:flipoff:. ive heard that about 20's and also aout 3.9's , just cant understand why??? if your telling the dyno it has 3.9 and the 20's are the same rolling dia as the 17's with 255 on them wouldnt it be the same... ive been told why before but can not remember...

I've got a manifold that would suit you perfectly :fishing:

[ice57l]

your stuck with that now... :flip2: hmmm will have to see what happens, will see in feb how it go's but i do waht 300! have to plan this carefully!

[vitob2006]

Dont worry about dyno figures. How does it drive??? What improvement do you want? What are u trying to achieve?
If you just want 1/4 mile times feed it the bottle and you will be pulling 11s easily if you can get grip. If you want more responsiveness and drivability let her breathe better with some heads (HIGGINS)
But you've got to work out what u want? F%$K the dyno figures.
You get 100 shot of NOs on a stocky with 200 RWKW with exhaust and a good set of boots and it would be faster than a 280 RWKW modified car. (Google it).

IMHO Don't centre ur decisions based on dyno figures man....big mistake!!!

[ice57l]

i know a shot of gas will get it going but you cant use it on the street! well 272 kw either, but i think ill just re ring it, new bearings and gaskets, same cam and springs, and then its the heads... hmmm either get my 241 done by higgins or ive been offered some ls2 patriots??? im thinkin the higgins ls1 ? but im open to everyones thoughts! just clean up the ls6 manifold aswell. i want it to pull more down low! my mates think i need to ride in a 240 kw car again as they think its good enought but i think it could just be alittle lacking! off to the drags on wed so ill see then

[klink]

I have a similiar cam.

i popped a motor and put a brand new crate motor in with all my old internals with same tune and went from mid 270's to low 290's with a fresh engine on a mainline. and am yet to do heads.

i know of others with similiar cam and heads making 305-310 pre heads they were mid 270's low 280's rwkw

my old engine only had 124000.

[ice57l]

thanks,, sounds like there is a ray of hope...

[SLEEPERVX]

What size Extractors have you got? Heads won't make much of a difference if you have 1-5/8" primarys you'll need to upgrade to see any notable gains.