HEADS!!!

 

Why? Please clarify your statement.


2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU / E-Fans
Street Edge TC / B&M Cooler / Stillen Exhaust

 

Nice looking heads bro. Always was a good way to get power. I wonder how well they'd do on our VQ?
You going this route?

<font color=red>GSM</font color=red>
<font color=red>GSM</font color=red>
<font color=black>Silverstone Coupe</font color=black>

 

Heads are always worth big power. Better tuning in the combustion chamber, more compression in this case. Hopefully bigger intake and exhaust ports, and while your swapping heads, why not switch cams (I think in this case you need new cams anyway.) I'd say that this mod, even with only slightly more aggressive cams, an intake, and exhaust could get the VQ up over 320 or 330 crank hp. I don't think I'll be going this route because of the cost. For the cost of the heads, cams, springs ect, I could buy FI.

 

Could you really buy FI (not including NOS) for the price of heads, cams, springs, etc.? So far all the FI kits seem to be near 10k in realistic cost (parts, labor, tuning, etc.). I really want to do something big with my car but FI just seems so expensive and even after all the money it's way risky. I don't know, I think I'm just confused. I'm that penguin getting smacked in the back of the head. [img]/w3timages/icons/smile.gif[/img]



BS 6MT/Premium/Navi/%5 Tint/Escort 8500/12' Rockford Fosgate Sub/Borla Exhaust

 

Not quite, but close. The Price of the Heads is $2000, springs $240, Cams (JWT) $1050. Assembly and instalation, probably about 10 hours plus. To install even cams only is a long job as the motor has to be pulled. I'm also going to go ahead and assume that the computer will have to be tuned also. That wont take quite as long as turbo tuning, but it'll take a while.

Oh, it says it will also require VK45 Valves and Retainers. I couldn't find any info on pricing of these, but can assume it'll be around $25 each valve... so that's another $600.

Total cost including 13 hours install and tuning time (assumed mean rate of $70/hr) plus all parts is....$4800.00 not included was tax. I don't know what the tax structures of different states are, but lets assume 5% and you can add another $240. Oh, I also didn't include the possibility of having to have technosquare do the chip... tack on $500+

am however going to revise my statement about power potential with the head/cam mod when combined with exhaust and intake and say more like 330chp or 335chp+... that's even more cash though. i'de say for $10,000 in N/A mods, the VQ35 could make about 340chp easy. But for $10000 in FI mods, you could push 450chp... or sell your car and but a M3

 

you have to factor in the high octane gas that you will have to use. 93+ is expensive in CA. very hard to obtain indeed

G35S 6MT
Technosquare ECU
350Z Springs & Struts
6-wire ground kit

 

Here in IL 93 costs $.20 more per gallon then regular. Not bad. 93 should be fine if tuned correctly

 

I have read about these heads and they say they raise compression to 12.3:1 You will need ecu tuning for sure and a very high octane fuel to even use them on the street. Good luck with the project.

 

<blockquote><font class="small">In reply to:</font><hr>

Not quite, but close. The Price of the Heads is $2000, springs $240, Cams (JWT) $1050. Assembly and instalation, probably about 10 hours plus. To install even cams only is a long job as the motor has to be pulled. I'm also going to go ahead and assume that the computer will have to be tuned also. That wont take quite as long as turbo tuning, but it'll take a while.

Oh, it says it will also require VK45 Valves and Retainers. I couldn't find any info on pricing of these, but can assume it'll be around $25 each valve... so that's another $600.

Total cost including 13 hours install and tuning time (assumed mean rate of $70/hr) plus all parts is....$4800.00 not included was tax. I don't know what the tax structures of different states are, but lets assume 5% and you can add another $240. Oh, I also didn't include the possibility of having to have technosquare do the chip... tack on $500+

am however going to revise my statement about power potential with the head/cam mod when combined with exhaust and intake and say more like 330chp or 335chp+...

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So you are saying that adding all that will only move the car up to about 335hp from 280hp? Basically all that only adds 55 more horsepower at the engine? That just doesn't seem right but I'm the first to admit I don't know much about this stuff!



BS 6MT/Premium/Navi/%5 Tint/Escort 8500/12' Rockford Fosgate Sub/Borla Exhaust

 

TAILS!!!

"Not all G35 owners are G35 Drivers"
2004 G35 Coupe 6MT-BS/BLK | Aero-Navi | Gounding Wires (Hidden by black conduit) | Clear Corners | 15% tinted windows | 350Z Tube | JWT PopCharger.....

 

Head jobs (no pun intended) are often only attractive over FI mods for "stock" race vehicles, where the regulations don't allow turbos, blowers, or N20.

If you are going all out with FI however, and money is no option, you may as well (or probably already plan to) upgrade your cams, crank, main seal, valves, v-springs, etc. anyway, so why not do the heads at the same time?


Black/Willow 03.5 6MT, Premium, Navi, Aero, SAT
350Z Nismo CAI

 

Having to use 93+ octange would be a PITA here in CA. All I see around here at all the gas stations is 91 ocatane. What octane do you need with FI?

 

putting these heads on ups compression, so putting the heads on would mean dropping compression with lower compression pistons even more. and with extreemly low compression pistons, there can be a lot of lateral play with the piston which can be bad for long term engine life. Onthe other hand, for race engines, this would be a good idea... but so would destroking the VQ35 so as to be able to rev higher.

 

2k2MaximaRIP, I don't think low compression pistons have anything to do with "lateral play". Pistons that lower compression usually do so by dishing the piston top. Stroker kits that modify the crank throws or add rod length (or pistons that change the location of the piston pin higher to fit longer rods) will increase side loading, which is what I think you're referring to.

Lowering compression on the G35 motor would be a smart thing to do if running forced induction, but otherwise, the more compression you can run on pump gas, the better.

There are no details given on this site about these heads, other than the chamber size. Do these heads also have larger intake and exhaust valves? Do the intake and exhaust runners flow significantly better over stock? Is the price for the bare head or fully assembled?

If the only advantage they have over stock is chamber size to raise compression, it would be a heck of a lot cheaper to simply mill the stock heads to raise compression (assuming there was piston/valve clearance to do so).

I'd do a lot of homework before changing heads, especially for two grand+.

You can't beat forced induction for bang for the buck. Just be careful of the "bang"! :-)

-- Mike

'04 G35 6MT Sedan
Diamond Graphite