Smaller pully
 

How are people able to put a size 3 pulley or smaller on your car?? I understand tune tune tune and scan for knock but dam I got all the goodies plus SS inter cooler, Xp cam, bored throttle body, and getting full headers next week... But zz performance said after I dyno tune after headers are on I shouldn't drop past my 3.25 pully...

Every engine responds differently. Also you might need a larger intercooler if you are just running a short-stack.

Gen V or Gen III? I'm on a 3.1 with hardly no knock on a Gen III with stock cam... so with any cam I could drop under a 3.0.

Gen 3

Full size IC? How much timing at WOT?

Edit - nvm I saw you have a short stack. Bigger IC is the way to go. I dropped from a 3.4 to a 3.1 and took the timing back to stock with adding a full size IC. Keep in mind, it took me getting my heads ported to run a 3.4 pulley (Had like 10* of KR before, the heads knocked it down to blips of KR)

Yea I see what you saying but when I hear people say they got a 3.1 pr smaller pully I'm like what they doing I'm not

Ss ic is holding you back. Tune is magic as well. Also are you top swapped or originally supercharged? Na bottom ends have higher compression which will make more power without dropping as much pulley size.

With same exact mods on a car:

Higher compression=bigger pulley
Lower compression=smaller pulley

Still make near the same power just one makes more with engine other makes more with the blower.

No I'm supercharged.. Dale jr edition and yea zz performance said they could tune it to make it more powerfully after headers... And before anyone asks yes it's tuned up turbo tim does every one of my tunes from the dyno

And ok the SS intercooler might be holding me back I can accept that thought

I also have mixed feelings on zzperformane tunes. I've heard some are ok and I've heard some were very poorly tuned.

I have had one tune from ZZP and it was ****. Made the car spit and sputter until it warmed up, and then randomly spit on heavy acceleration. Put my old PCM and tune back on it and guess what... ran like it's supposed to.

OP - ported heads and a full size IC will get you where you want to be. Just my opinion. You could even pick up a spare set of heads for cheap and port them yourself using clubgp.com's DIY head porting tutorial.

The tiny pullies are for heavily modded engines. No offense, but you have a pretty mild setup. Looks to be mostly bolt ons other than a fairly mild cam.

Your cam is right about in the middle of the road as far as 3800 cams go- it's certainly not a very aggressive cam (nor should it be- it's designed to maximize stock heads). You have the smallest possible IC to get rid of heat, and you have stock heads.

You just can't expect to be able to run a tiny pulley with a setup like that.



If your only goal was to run a tiny pulley without changing your current setup, that could be made to happen by tuning. You could pull timing across the board, and load it up on fuel. The thing would be a turd, but at least you could run a tiny pulley with huge boost numbers.

The mentality changes many years ago in the 3800 world. People used to strive to get down to 2.8 and 2.55" pullies, but people started to realize that you're way out of the blower's efficient range down there. You're pumping in a ton more heat for less and less extra air. So the trend started to go towards higher compression (at least to the 9.4:1 NA bottom ends) and running higher timing numbers at lower boost levels to make more power. Sure, some heavily modded setups still get into the tiny pullies by necessity- but just chasing a pulley size isn't the end all on these engines.

With a good tune and a good big ic he could run a 3.0 pulley and make 300ish whp. My buddy has done this so it's possible. He is stock cam and stock heads on a set of 1.9 rockers. He did it in a Bonneville and ran a 12.50 in the 1/4.

A huge ic and a good tune will get a 3.0 pulley I feel. Every car responds different to mods though, you will just have to see

We'll I'v already got 286 to the wheels last dyno run and 322 torque


And it think I'm well past bolt ons actually yea I didn't buy new heads or pistons true but very far away from being a bolt on racer . I personally think touching the heads with these cars aren't worth it

Heads on these cars are VERY worth it

How worth it??? Just need to be ported or what?

heads are a major restriction in air flow when getting into higher hp supercharged 3800's. the more air you get in and get out the more power you make. porting helps a ton and also bigger valves. heads are expensive but if your going for an all out build you need them. also self porting them is not easy, if its not done a certain way you can make them flow worse than factory heads. (need to keep the D shape)

and let the bottom end stock, no need to touch it

We'll after all is said and done I did have enough room to move to a 3.1 pulley... But wow I do question my tune big time, not that I have any knock but how the guy did it

Any further details?

We'll I got headers put on and then the Dyno That's when problems started....after first test run it was kinda week. Then after some questions I had to tell him that I did have an intercooler because he didn't know I'm like what the ****... Then last pull (2 total) it ,asked out at like 275 at wheels which I thought in my head is quite low since last dyno I was at 283 and all I did is put headers on. I asked him what's up he ****in told me that he isn't the best tuner on 3800 engines nor does he tune much of them. But he did say I could drop a pulley size or 2 . My boost only was at like 7.5#. So they swapped pulleys and just scanned for knock and away I went. And I told tim NEXT TIME YOU TUNE IT. He is the only one who I think can do it right

But driving home down 96 I must say it had lots of power but don't think the TRANS can handle all of it

Is this an L67 or a top swapped engine? If you're only making 7.5 psi of boost, thats quite low. I can do that with my stock setup.

Naw after 3.1 put on I'm back at 10 pounds again

Idk where your located but you need to find a good tuner that knows what there doing. Brian turner at dyno tune motorsports (columbus ohio) is who helps me with my tuning and he is amazing. I recommend everyone to him. he tunes all vehicles now he has his own shop and that's all he does is tuning. (He used to do all of intense racing tuning back in the day so he is very familiar with the 3800 as well)

And as far as boost pressure you will loose some boost with headers, cam, etc as its more free flowing. This does not mean you lost power if you lost a little boost psi by any means it just means you probably can drop a pulley and make more power now do to more free flow.

Not being funny but re read what I posted. I said it dropped to 8 pounds then dropped a pulley size and back to 10 pounds

I was explaining the boost drop to leprechaun....

My bad

I didn't mean to say you haven't done a lot of work- but really the 3 major things to be able to run the tiny pulleys are heads, a big cam, a big IC (obviously headers included, but all of the common headers are pretty much the same). You don't necessarily need all of them, but right now- you don't really have any of them. If running a super tiny pulley is your goal- you need to work on one of those 3.

Porting heads is certainly worth it. These heads flow terrible anyways, so they can use all the help we can give them. Look at the top HP charts- nearly all of the record HP numbers on M90 setups have some sort of head porting.

Also, don't touch the pistons/bottom end- it won't gain you anything.

Sounds like you need a new tuner. How is this guy tuning the car when he doesn't even know if it's IC'd or not??

Also, it seems odd that you lost 8 whp from headers and a tune (if I'm reading that right). I'm sure temperature and such was different, but something doesn't seem right that you'd lose that much with more mods.

I would stop worrying about boost. Boost on a M90 3800 isn't particularly important. You could put a big nasty cam in there and your boost will tank, but you'll end up making more power. KR is the main concern- drop pulleys to the smallest one you can safely run without KR, and forget what boost that puts you at. Boost doesn't directly correlate to HP, especially when you start adding mods that improve engine flow.