Pulley size.

[newz]

What is the diameter of the stock ZL1 lower pulley?

[crazydave]

Originally Posted by newz

What is the diameter of the stock ZL1 lower pulley?

Just under 8".

[newz]

5ckcuf and crazydave thanks for the information and recommendation. I am thinking a 10" might be a good compromise for road course use coupled with header.CAI, and a tune.

[JB'sZL1]

Originally Posted by newz

5ckcuf and crazydave thanks for the information and recommendation. I am thinking a 10" might be a good compromise for road course use coupled with header.CAI, and a tune.

I thought above 9.5" a cam was necessary (else you're just generating heat...not hp). I'm planning on going 10" with cam, headers, 1050's, etc.

[ZL1 FOR ME]

JBsZL1 I meant a 10% (8.66") Pulley. Thanks for catching the typo.

[Can'tHave2MuchHP]

Stock pulley is 7.8".

The aftermarket options are:
Lowers:
8.6" - 10% (Good for stock injector setups, anything beyond this and injectors will need to be upgraded)
9.1" - 18% (Upgraded injectors necessary, good amount of overdrive for road course work with a HX upgrade)
9.5" - 22.5% (Upgraded injectors, heat exchanger are necessary)
10" - 28% (Upgraded injectors and heat management are necessary)

Uppers:
3.0" (Stock)
2.5" - 18%
2.38" or 2.4" - ?%

Any combination of the above pulleys that results in over/much over 35% is a BAD idea if you don't want to deal with a lot of heat/octane problems. Sure sure people do it, but it's not recommended by any professional shop unless you're doing an extreme Heads/Big cam/E85/Meth build. Your bearing wear is going to be brutal too.

For road course work, I'd either go 8.6" or 9.1" unless you're good with doing cooling mods like a heat exchanger, thermostat, E85/Meth, etc.)

Also, definitely get injectors if you can swing them, even at 10% some people were running out of fuel, every car is different. A lot of magic can be worked in the tune, but it may just go boom. Once you upgrade the injectors, your only next problem is too much pressure (Going past 22.5% without a cam, no go) and heat (Always a problem no matter your cooling mod level).

[ZL1 FOR ME]

Can'tHave2MuchHP Thanks for the pulley info. I do about 15 track days a year. I am going to try for 20 days this year. The extra weight of the HX on the front end is what I am trying to stay away from.

[hammdo]

I have a 2.45 and 9.17 (18%) on mine, 1050x injectors, cooling mods, with e85...

Planning for what you’ll be doing is great advice.

I have 3 hx (in parallel), dual intercooler pumps, trans, and oil coolers up front (auto) so, if your going more power, you’ll need to account for the cooling. I do track mine..

-Don

[ZMEnow]

Originally Posted by ZL1 FOR ME

Can'tHave2MuchHP Thanks for the pulley info. I do about 15 track days a year. I am going to try for 20 days this year. The extra weight of the HX on the front end is what I am trying to stay away from.

HX weight is not a factor, if you want to reduce your IAT's w/o changing the HX you should get a reservoir, and use water wetter.

[newz]

hammdo and ZMEnow thanks for the info. I do have a D3 coming and am undecided on .HX There seem to be several good ones available. LPE is local and has some pump up grades available. hammdo you have a great build thread. Yes you do do track days:-)

ZMEnow what HX and pumps would you recommend?

[ZMEnow]

Originally Posted by newz

hammdo and ZMEnow thanks for the info. I do have a D3 coming and am undecided on .HX There seem to be several good ones available. LPE is local and has some pump up grades available. hammdo you have a great build thread. Yes you do do track days:-)

ZMEnow what HX and pumps would you recommend?

With a 10 pulley, headers, CAI, and D3 reservoir the stock HX should be good for road courses. I think Ted J had made some comments on how efficient the stock HX is up to a point. He noted you can get too big of an HX that will block the radiator and cause more problems that it solves on road courses. For the mods u have listed I would just change the fluid to Water-wetter mix and have at it. Since you live n Ohio and not Texas you only have end of July and August that gets nasty.

Remember whatever HX you use won't cool below outside temp, so on a 90 degree day you start from that temp and add the cooling properties of your choice of coolant plus the additional boost heat. Welcome to the world of SC's they love cold, but your tires don't.

[hammdo]

For summer racing, 100% distilled and water wetter, nothing works better. When it gets colder out, then you need a 50/50 mix — where your located.

I run 100% all year since we don’t get too many freezing days here — and I heat the garage when it does ;o)

Run the same mix radiator and intercooler...

Can help with racing and recovery...

I have an upgraded radiator so I have no problems there, plus on hot days, I kick the heater and blower on high and have one vent open on the dash, old school style, really helps on those 105+ track days (windows are open so it vents out nicely)...


-Don

[newz]

ok A couple of questions for hammdo and ZMEnow.
I have a IW balancer and a 9.10 Metco baalancer coming. Do you guys think a Ron Davis HE will work for cooling, Also have a D3 reservoir lined up. ID 850 injectors ordered also.
Will the stock ZL1 heat exchanger pump work and what is a good way to handle the increased fuel needs? Kooks headers and connector pipe are in the garage:-)
Also have a cai BY CAI already installed. AnnnD what is the recommended spark plug range for all the above?
SCT tuner will be coming along with Teds tuning prowess.
Maybe more than a couple of questions:-)

[hammdo]

Ron Davis is a great hx — I have it. D3 is a great reservoir will help quite a bit.

So, are you going to drag, autocross, road race, or a combo? That may lead to more questions...

The zl1 pump is great and is the same as the varimax pump — volumn wise.

I was running a 7 heat range before e85, now have an 8. Ryan from GPI let me know what I needed to run so, your tuner will likely do the same.

If you even think you’ll go e85, get the id1050x injectors now or you’ll be selling the id850s like I had to do ;o)...

-Don