My mods are listed below. I want a set of heads that will work well with the 5151 NOS kit. Am I right in assuming that I should stick with Iron heads to keep the CR low? How big should I get with combustion chambers (64cc,76cc?) and intake runners 180cc-230c?). A cam and custom chip would probably follow the heads along with some ignition stuff to pull timing, colder plugs, and other N2O precautions. Any info on the subject would be much appreciated. Thanks.

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"Though I cruise through the valley of Rice I shall fear no turbo, for torque art with me."
--Cullan Hooley
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1985 IROC-Z w/T-tops, 305 out and 350 L98 TPI engine in, Hooker Super Comp Headers, 3" Hooker Super Comp Cat-Back, 3" CatCo Cat, Rebuilt TH700R4 with Shift kit, 2,800RPM Torque Converter, 3.73 Richmond gears, Auburn differential, Accell SuperCoil, Accell 8mm racing wires, BBK AFPR, Homemade Ram-Air (thanks to Andris Skulte), MAF screens removed, Dropped A/C, Dropped A.I.R, TB coolant bypass, Hurst Dual-Gate Shifter, SLP Air Foil, K&N filters, Holley performance fuel pump, Spohn Subframe Connectors, Re-located Spohn Lower Control arms, and more to come.

 

High or low compression ratios can work quite suitably with nitrous oxide provided the proper balance of nitrous and fuel enrichment is maintained. NOS kits are used in applications from relatively low compression stock type motors to Pro-Modifieds, which often exceed 15 to 1. Generally, the higher the compression ratio, the more ignition retard, as well as higher octane fuel, is required.
It is best to choose a cam tailored to normal use (when nitrous is not activated) since 99% of most vehicle operation is not at full throttle. There are special cam grinds available for nitrous competition which have more aggressive exhaust profiles etc. Since cam selection depends largely on vehicle weight, gearing, etc., it is best to stick to cam manufacturer's recommendations for your particular goal.

Only if the chip had been designed specifically for use with nitrous oxide. Most aftermarket chips use more aggressive timing advance curves to create more power. This can lead to potential detonation and when dealing with N20 it means it literally.


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88 Firebird Formula
350 T.P.I. (Stock unfortunately)



[This message has been edited by IH8FORD (edited August 23, 2001).]

 

iron or aluminum shouldnt affect the compression raito of an engine much, if any. it should only have to do with the volume of the cylinders, combustion chamber cc, head gasket cc, and piston valve relief cc and maybe piston to deck clearance, but im not sure about that one. i would get the heads that would best suit your needs within a reasonable cc, then you can get all different types of pistons to get your desired CR. (i.e. dished, flat top, domed)



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former 305 crossfire fuel injection
350 cubes
hooker headers
750 vac secondary
700r4 with shift kit
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"no man with a good car needs to be justified."

 

Small chamber AL heads.
Smooth out the chambers.
The smaller chamber has less surface area so less heat is absorbed by the cooling system, meaning it's used to push the piston down. Properly tune in a 10:1 motor they only need to run 28d timing, so when you do retard the timing it's not as costly.

Might start while stock learning about chips, rather then when everything is done, and go "now what".