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.