Hey Guys,

I had read about people putting an AP1 intake cam on a 2.2L to help make more power than the comparable ap2 intake cam. People said that the longer duration would help make more power!

The plan had been originally to just put the ap1 cam in, but i gave in and bought a 3inch exhaust and built a 3inch downpipe as well!

The motor had been dynoed in reborn56's old car, which was an ap2. I had switched the motor into my car, keeping everything the same except that i used my AP1 tranny instead of the AP2 in reborn's car.

The motor made 384whp with a stock exhaust, 3mm headgasket, GM 3bar map sensor, 750cc RC's


I had jeff evan's up the rev limiter to 9K to see if the power didn't fall off as sharply as it usually did with AP2's. When we rev'd it, the power didn't drop as drastically as it had done, but it was still falling (probably more to do with my turbo setup) Unfortunatly those dyno sheets were skewed because he thought this had an AP2 tranny. He said that the torque numbers on AP1 tranny will be lower compared to the ones of an AP2 tranny, but the horsepower should stay the same.

This is the new dyno sheet with the only differences being an AP1 intake and 3inch DP and single exhaust.


Comparing the two sheets, the most noticable change is that with the ap1 intake cam, the boost comes on 500 rpm's later. This was the same for low and high boost setups. With my Ultimate Racing manifold with 60-1 the highest numbers i got were 420whp at 18 pounds of boost. At the same 15 pounds of boost my old setup made 384. i made 398whp. At 10 pounds of boost i made 365whp and a flat 225ft/lbs of torque. Jeff said he was surprised my car made that much power, considering how badly designed the UR manifold is. This setup, or at least the manifold, is only really efficient to 14 pounds of boost. I did have Jeff monitor the IAT's and on my setup, i did not see IAT's go much higher at 18 than it did at 10. I'll do some datalogging and see for myself on the street.

There is nothing definitive with my findings, considering the changes i have made since the the dyno pulls. The motor has had 25k miles of boost on it... so that might also have an influence. But what i think can be shown from this setup, at least from a spool perspective is that with a log style manifold, the AP1 intake cam takes 500rpms later to fully spool. This is also with a full 3inch DP and exhaust compared to a 2.5 DP and stock exhaust from before. My tuner had told me that with a tubular manifold, the longer duration of the AP1 cam should increase power, but with a log style manifold, power would be lost or stay the same.

I am only posting this up so that other people might learn or get insight into my results! I think if i was to do this again, i would have gone for a tubular manifold, like a Full Race setup and called it a day. I hope this helps out someone looking to switch out cams!

 

Good info.

I'm going to prob have to say most of the gains is from changing the downpipe and exhaust rather then the cams. I think the cams just account more for the later spool time. I'd be very interesting to see a straight swap between the same engine only changing the cams.


FWIW, I gained nearly 30rwhp from a 2.5 inch invidia with testpipe to a 3inch single. I'd expect way more gains changing from stock to a 3" single like in your set up.

 

Yeah, I don't doubt for a second the power made was due to the exhaust. The change in the spool was my main point on the cams!

I would be interested in a racing a higher horsepower setup, but lower torque car and see how i fair. Eventhough i make less horsepower than alot of the 400+ turbo cars on the boards, i am making some decent torque numbers!

I have to say, i have been let down by the Ultimate Racing setup since i got it. Everypart of the kit is subpar compared to others on the market, it even lacked the supposed reliability of a log compared to tubular manifold! As i said earlier, if i was to do it again, FR tubular all the way!

 

your test is not nearly scientific enough to even begin to suggest that the ap1 intake cam is affecting the spool like that. I could say its because of your exhaust, and you have no way to disprove me, lol

 

I'm with you on being disappointed on the UR kit. Took me a while to de-bug some of the flaws like bad thread holes, material overlapping holes in the manifold, etc.

The UR kit also included screw-type clamps instead of T-bolt clamps, they didn't provide an oil restrictor in the supply for my turbo which caused the turbo to leak a slight amount of oil (compressor side only, since it showed in the compressor outlet but no blue smoke). Poor instructions on bolting up the downpipe to cat as well.

Bolts kept vibrating loose (esp. wastegate). I figured the manifold needed to be braced from below (not part of the kit, rather, something done since we're hanging a 25 lb weight off a 9000 RPM 4 cyl -- really helped the NVH).

Not the best placement of an intake filter either (behind the 200 degree F radiator air, which Brink Racecraft fixed with a neat cold-air induction system). Last thing that cheesed me was the 9 PSI spring they shipped in the wastegate instead of the proper 7.4 PSI one. Yikes.

Once we got it de-bugged, it was fine for a couple of years at 290 to the wheels on 7.4 PSI. I've been spoiled by the quality of Mugen (true bolt-ons) though, and it was frustrating to deal with UR's customer service.

FWIW, they did a great job on the intercooler pipes and location of the intercooler. Their Greddy Blue tune wasn't too bad either.

So for those who would like to avoid teething pains, below are some shameless plugs for the parts/services included in my rebuild (finishing this week).

Full-race tubular mani & downpipe,
Precision 600 HP intercooler (recessed and located upward to retain stock grille),
Brink Racecraft cold-air induction for turbos,
GT3076R with oil feed restrictor,
ATP Turbo's clamps, fittings, oil-return hose,
Laskey 9:1 short block plus Stage 3 head

Installation by John Long at JC AutoSpec in Round Rock. Can't say enough about these guys if you're in the Central TX area. They obsess on the details -- fit, finish, robustness, NVH, durability, performance... All the angles.

And keeping it on topic, I'd welcome any recommendations for shops in CenTex that can do a quality 3" exhaust from the catalyst back.

 

There are many factors that weren't repeatable in the dyno pull... and i said that in the post. However, i have never seen a more efficient exhaust slow down the spool time of a turbo. I went from a 2.5 inch downpipe and stock exhaust, to a 3inch downpipe and 3inch single exhaust. Take that for what it is!

 

Cant wait to see your numbers
Id like to see pictures of your air intake
Anything is better then in front of the engine

Marcus