Time for a bigger pulley?

[tann3r]

Well i got bored and built my block, put oversized valves in the head and added water injection. I also put on the 115mm pulley i had on the shelf. It seems that the oversized valves are flowing a bit more and i'm only seeing 11psi now. I was seeing 10.5ish on the 110mm and the stock head and block.

Was out at the track last weekend and got that itch for more power. So anyone think a 120mm pulley is in order? Maybe a 130?

[Tom @ Fast Forward]

How's your A/F? Do you have a Timing Card?

[tann3r]

I also swapped in 315cc injetors. AFR starts at 12.5 @ 3k then taper down to 11.6 @ 7k. E-cool is turnd down to 3.

No timing card, but the knock sensor is not pulling any timing. I think the 8.6:1 wisecos and water injection are keeping the knock in check.

[Tom @ Fast Forward]

Sounds like a good candidate for a bigger pulley. :)

[lowboy72]

Well i got bored and built my block, put oversized valves in the head and added water injection. I also put on the 115mm pulley i had on the shelf. It seems that the oversized valves are flowing a bit more and i'm only seeing 11psi now. I was seeing 10.5ish on the 110mm and the stock head and block.

Was out at the track last weekend and got that itch for more power. So anyone think a 120mm pulley is in order? Maybe a 130?


I am in the process of having my block built as well. Did you dyno your setup with the 115mm pulley and the rebuild? Also if you don't mind disclosing, what kind of headwork did you get done?

[Tom @ Fast Forward]

<cough> 130 <cough>

[tann3r]

Haha Tom :) I'm still thinking about it, but last time out at the track things started getting a bit hot. I need to address some cooling issues before i step up to the bigger pulley.

I guess 90*+ weather, 80% humidity, and a bright sunny day make for hot times. I'm planning on adding an oil cooler and adding a vent to the hood; as the 53mm Koyo was barely keeping up. I also think moving the intake away from the back of the radiator is a good idea. But those are currently on hold as i consider other avenues for a dedicated track day toy in the form of a LS1 FC.

As for the head work i cleaned up the casting boogers myself and had the machine shop do a 3-angle valve job when they install the 1mm oversized valves. nothing special really. Havent had time to make a trip to the dyno yet, been traveling a bunch w/ my new job.

[FormerDatsun510Man]

Forged rods? If so, you could safely go past the 130 pulley even :biggrin:, as long as you have the cooling and fuel capacity of course. FWIW, on the Hotside, the power peaked out with the 150 pulley.

[Tom @ Fast Forward]

110F Tuesday. 45F right now and it is snowing in the mountains today. Must be global warming?

Did you seal the radiator to the fan shroud?


Haha Tom :) I'm still thinking about it, but last time out at the track things started getting a bit hot. I need to address some cooling issues before i step up to the bigger pulley.

I guess 90*+ weather, 80% humidity, and a bright sunny day make for hot times. I'm planning on adding an oil cooler and adding a vent to the hood; as the 53mm Koyo was barely keeping up. I also think moving the intake away from the back of the radiator is a good idea. But those are currently on hold as i consider other avenues for a dedicated track day toy in the form of a LS1 FC.

As for the head work i cleaned up the casting boogers myself and had the machine shop do a 3-angle valve job when they install the 1mm oversized valves. nothing special really. Havent had time to make a trip to the dyno yet, been traveling a bunch w/ my new job.

[tann3r]

Yep forged rods in the motor. Having driven my buddy's 430rwhp GTO i have a new power craving that i dont think the miata can satiate. and since he doesnt wanna risk his DD at the track, we brainstormed up the LS1 FC idea. cheap, reliable 300+ hp. so we're seeing how it goes.

If i didnt track the miata I'd be all over the 130mm pulley, it was only towards the second half of a 25 min session that water temps started climbing. Texas world speedway is a pretty high speed track. 2.9 miles, avg lap speed ~80mph, 135mpg on the front straight and 110mph on the back straight, slowest corner speed is 55mph. I think its the sustained on-boost and high rpm that are taxing the cooling system...just a bit :) I'm sure the car would be fine street driving at those boost levels.

The fans are shrouded, as is the top of the rad., the sides and bottom of the rad need better sealing to the mouth. its a work in progress..

[jwalton]

...and since he doesnt wanna risk his DD at the track, we brainstormed up the LS1 FC idea. cheap, reliable 300+ hp. so we're seeing how it goes.


I ran across something else that seemed interesting for a project. Think Porsche 914 but with a Chevy smallblock. I saw one two weekends ago at a local show-n-shine and it was amazing. Total sleeper. I've done a few hours interneting on the concept and it seems that the smallblock will fit with no panel/firewall/strut-tower modifications. Pre-'74 hardware means no smog checks and then generation 911 suspension bits are a direct bolt-on upgrade. Weight and balance? As far as I can tell, if you get aluminum heads, the weight and balance are probably not distinguishable compared with a 914-6. At least that's what the people say that sell the kits...

Now, can the chassis handle the torque? The transmission and the rest of the running gear?

If I only had the cubic dollars to waste finding out.

[snakebit]

I ran across something else that seemed interesting for a project. Think Porsche 914 but with a Chevy smallblock. I saw one two weekends ago at a local show-n-shine and it was amazing. Total sleeper. I've done a few hours interneting on the concept and it seems that the smallblock will fit with no panel/firewall/strut-tower modifications. Pre-'74 hardware means no smog checks and then generation 911 suspension bits are a direct bolt-on upgrade. Weight and balance? As far as I can tell, if you get aluminum heads, the weight and balance are probably not distinguishable compared with a 914-6. At least that's what the people say that sell the kits...

Now, can the chassis handle the torque? The transmission and the rest of the running gear?

If I only had the cubic dollars to waste finding out.Is that the Renegade conversion kit?
Everyone I know who has driven a 914 says the handling is unbelievably predictable, controllable and buckets of fun. 914s always seem to dominate the track on lap days.

[jwalton]

Not sure. I tried to find it again really quickly, but couldn't. It sure does look like fun though...