Rumblefrog

A few weeks ago, I replaced head gaskets. In the process of tearing things apart, I discovered that my upper intake manifold was cracked, so I thought this would be the opportune time to switch to the GT-40 (explorer) intake. I finally got everything put back together and used a new upper and lower Explorer intake. I reused my stock mass-air meter, my stock throttle body and stock injectors. The only things changed were the upper and lower intake manifolds. I am using AFR 165 heads, E303 cam and 1.7 roller rockers.

I just got back from a test drive, and I feel like I've lost bottom end power. Does anyone else have any experience with a similar swap? Is there a solution?

NoGo95GT

When I intalled my GT-40 tubular intake only I did indeed lose low end torque.Why? Bascally, you did not lose any actual torque or horsepower, you just moved the power farther up in your powerband. The stock intake, heads and cam are excellent in making low end torque. However, now that your induction is properly set up, you make your power farther up in the rev range. Lower rear end Gears are great for making your car feel like you have gained your low end torque back.

mjr46

make sure you set the timing properly and allow the ecm to compensate for the new change made, give it a few days of driving

Rumblefrog

Thanks for the info. Where should my timing be?

mjr46

13 degrees base has worked well for me, make sure you set base with spout out

BlessedHellride

MJR46, what did you have your base timing set on your 85, and how much total timing did it have in it?

mjr46

i THINK i HAD it set at 13 with a total advance of 36.....I run a MSD pro billet dizzy

BlessedHellride

I too have MSD Pro Billet Dizzy with 6AL box and Blaster 2 coil. I knew I had some left in the ol girl. How much hp difference do you think it would be from going from 9* to 12*-13*. Mine is set at 9* base and I think it fell in somewhere around 32* total. I left it there while I was doing other things and didn't finish like I told myself I was going to do. Then I brought back the timing light I borrowed from one of my machinist friends. I just never gotten around to resetting it.

mjr46

I haven't maxed mine out yet either, still configuring things and trying a few things:

BlessedHellride

Makes note to self - * First thing to do, reset timing. Second thing to do, weigh the car @ Oneal's Feed Store.*