Hey guys this isn't the average noob thread of hey can i run a 2.5 on stock injectors lol.

Anyways, I have every cooling mod in the book what is the smallest pulley that would be wise and efficient to run? With a 3gph meth nozzle I am not seeing 140 iat2's, not even on the dyno with less air flow.

I need more power and until I get the ported intake and the killerchiller THIS MONTH , I am going to swap pulleys.

What would be the lowest pulley I could run and still be "smart" about things. I want to stay safe and conservative but I believe that's mainly in the tune. Also, would I need to re-tune again?

 

id go with 2.6

 

>2.66"

 

2.6. i believe ZZP offers a MPS that will allow you to go down to 2.6 without machining the snout...

 

If you are on the gm hub I have a Smoothflow 2.7 with bolts brand new for sale. See the link in my sig or pm me if interested.

 

i am on the gm stage 2 hub, whats the smallest that can run?

isn't it 2.7?

 

lol nothing is safe with this car if the damn internals were such garbage ppl would be throwing 2.5 ont here with stock injectors since day 1

yes 2.7 is the absolute lowest

 

2.7 is the lowest on the stage 2 hub gotcha.

I am pretty sure the car would be fine with a 2.6 or so, especially since I have full 3 inch exhaust.

 

2.8" is the lowest you should go.

The blower becomes inefficient after that size, which means it eats more power than it makes.

I'm sure me saying this though will start an all out war however, just figured I'd be of help before the minions come in here.

 

welp your one of the few that took all the precautions you have all cooling mods your tuned so its not like the car isnt ready for it and if u hit 280 with the 2.8 you shouldnt have a prob hittin close to 300 with a 2.6

 

I know the killerchiller and ported intake will really help me out this month on hitting 300whp. However, I don't want to be stupid about it. If a 2.6 or 2.7 isn't safe I am not going to use it.

inefficient and less power are 2 different things alphajaguar5. I am sure a 2.7 makes more power then a 2.8 but we could argue that if you would like lol.

 

wow, I can't believe no one asked him what he plans to rev to. That has more to do with what pulley size he can run than ANYTHING else.

Zach, how high do you plan on reving?

 

7,000 usually redline is set to 7200 rpms. Glad you thought of this because in my rush I didn't even think to mention it, thanks buddy.

 

2.8 is the lowest you want to go. Anything lower than a 2.8 and you will be overspinning the blower. This will also keep you most efficient with the smallest pulley. You go lower, you will start dropping efficiency a lot faster.

also, remember the smaller the pulley, the more heat.

For Reference:
2.8 will put you at max rpms at roughly 7150 engine rpms.
2.7 will put you at max rpms at roughly 6850 engine rpms.
2.6 will put you at max rpms at roughly 6600 engine rpms.

 

great thanks man, I will keep the 2.8 then and rev to 7150 roughly. Do you think on stock internals valves springs all that stuff im fine reving to 7200 redline? I have never hit redline at 7200, but tom put my redline up there. I dunno why but he said that the stock tach was a lil off or something and set it to that and said i would be fine. Thanks ralli

 

The stock internals should be good to about 7500-7800 RPM's and then you'll begin to see valve float...

(FYI Stage 2 Revs to 7200 RPM's)

 

actually stage 2 revs to 7k redline, I would know because I had it for quite awhile. Also there is no way that the stock valves can hold to 7500-7800rpms. I had a buddy hit 7500rpms with stock internals and now has valve float.

Please don't post misinformation, it could harm noobs.

 

What about just going with 2.75

If I just calculate this roughly, this would result into a MAX RPM around 7000 ((7150+6850)/2)

.

 

Every car is differant. It's not an exact science. Not to mention how often was he hitting 7500 RPM's? How hard did he beat on his car before he upped the rev limiter? There are so many factors you have to take into consideration before you can say they can't handle something and that's just a few of them. If the motor has been whooped on or not maintained correctly then yea you take it to 7500RPM's something's gonna break.

 

Don't waste your time below a 2.7 or 2.8. Go for full cooling mods and some traction mods. It will make your engine last longer and get better results.

Cooling is everything

 

eh, if you want to start half sizing the pullies, by all means, go ahead. The gains are tiny though.

Well, to answer this question aside from all the BS. I personally set my rev limit to 7500rpms. So I guess since I shift a tad before that, I probably rev out to 7400ish. I'm on the stock valvetrain, haven't pulled the engine apart ever. Raising my rev limit to 7500 was the first thing I did to this car. I haven't had a problem ever and have been doing it for over a year. When I tested the gain from doing this at the track, I picked up 2mph in the quarter.