New cam, what's wrong?

[Chuck]

The car is back on the road with a BoPort 1.9 cam. I have it timed at 10 deg BTDC with the spout out. It seems that there is absolutely no power until about 3000 rpm. I did have an A237 cam and the bottom end was very responsive. It feels like a 4-cylinder car until about 3000 when it opens up. Does this sound like a timing issue (or too much vacuum for the boost to overcome ;^))? Any suggestions are welcome. Idles smoothly at 900-950 RPM...

[chalkys_explorer]

What other mods do you have??

My 1.5 is a little low till 2500rpm so maybe it's just the nature of the cam?? Try contacting Bo to see if this is the sort of response this cam is designed for.

[GAboySVO]

This from Bo's web page for the 1.9.

"Rpm range of 4000-7000"

You can shift the power/torque band down the RPM range by advance the cam with an adjustable sprocket.

[Pat_in_L.A.]

Double check the cam timing to make sure that it's not retarded by a tooth or two. That's a common mistake that everyone but Mike Fleming makes (or won't admit to).

[Alex L]

It IS a 4 cyl car till the hairdrier kicks in. No power till 3500 with that cam.

[Pat_in_L.A.]

It IS a 4 cyl car till the hairdrier kicks in. No power till 3500 with that cam.

He may be used to max torque at 3100 like the stock cam that came out. Just a thought.

[Chuck]

The no power until 3500 is OK but there doesn't seem to be any boost until about then either. If this is normal then OK but it''l take some getting used to; I used to have some bottom end torque with the A237 and 2 deg retard.

[SVOJames]

I'm running a 237 in a big valve head, ported & polished by Motion Dynamics, T3/T4 from Charlie, ported E6, dumping into a 3 inch DP & cat, then going dual 2.5 exhaust.

Sweet spot for me is around 3400, but boost comes on early enough at 2K that I don't have to down-shift from 5th to climb most mountains.

I'm replacing my 237 with a Bo 1.5, I'm just offering my opinion.

[SR71-SVO]

cam

Do you have a vacuum gauge? If so what does it say at idle?

[Chuck]

Do you have a vacuum gauge? If so what does it say at idle?

I don't have a vacuum gauge but it idles very smoothly; something I was thinking would not happen with a 1.9.

[Alex L]

The no power until 3500 is OK but there doesn't seem to be any boost until about then either.

when i went from a ranger roller to the 1.9, my boost onset occurred a few hundred rpm sooner; full boost (38lb/min @ 17psi) still hit @ 3500. but boost came on a lot smoother, the RR was on or off, the 1.9 was very linear. up a hill, i can hold 5-8psi of boost from 2500+. hy351 12cm turbine housing.

He may be used to max torque at 3100 like the stock cam that came out. Just a thought.

its definitely a ... different experience then the stocker cams.

I don't have a vacuum gauge but it idles very smoothly; something I was thinking would not happen with a 1.9.

the cam itself can idle quite nicely, the problem lies in sizing injectors large enough to handle the airflow up top, without dropping below the base inj offset @ idle. even with the 35#ers on it, i couldn't get it to idle below 1,000rpm (MAF sensitivty limited, bet i could have gotten it to stock rpm with a proper backflow enabled bin.. but i digress). with the 83#ers, .75ms PW @ 1250rpm, and it gets real rowdy below that.

[Chuck]

I'm running a T3/T4, 35# injectors, ported E6, K&N, stock bottom end, 190 lph pump, stock exhaust.

[SR71-SVO]

The vacuum reading could give you an idea on how the timing is set. Ask Bo what is normal vaccum for that cam and then check your vacuum reading.

[P.D.R.]

How much boost? And any work done to the head? i.e. bigger valves or port work? I daily drive a 1.9 and it does require a lot more downshifting than say a stock cam, RR, A234, or AMS.

[Chuck]

No head work at all. I also am running an LA3. Bo suggested an advance of 4 degrees on the cam to regain some bottom end. There is NO bottom end at all right now. I'll re-check all of the measurements again now that it is starting to cool off (Saturday was only 105).