Double check and clean your maf - something's not right. You should be putting down at least 50 hp more. The bucking you talk about under 1500 isn't right for a mild cam like that. My 185cc headed mildly cammed 408 puts down 425 to the wheels, so you should do better than that with AFR 205s. The TB is a little on the small side, but I doubt it's hurting it that much. Did you degree the cam per Ed's recommendations?

 

Back the timing up a little. 28-29

The headers are really killing it.

So is the cat mid pipe dia.

Little stuff like this will really make it look bad quick. Also what did you come up with for afr.

Tim

 

Yeah, my first thoughts, tiny headers and exhaust and a throttle body meant for a mild 347. She can't breathe!

 

Something definitely seems amiss. We have remarkably similar setups. (89, MM suspension, 408, except I had gt40y heads, xfi 236-hr14 cam, and a victor efi intake, 1 3/4" long tubes, no cats) and made 380 rwhp. I'm in the process of upgrading to AFR 205s and a FTI cam.

Don't you think 13.4 is a bit lean for a WOT pull? I'd feel a lot more comfortable at 12.9, if not closer to 12.4. As for the dyno, if I didn't have rpm and torque numbers I would feel like I wasn't receiving what I paid for. Given that malfunction, it makes me doubt the accuracy of the other numbers displayed. Perhaps a retest at a different facility is in order.

 

One other thing...if I spend all of this money on mine to upgrade heads and cam and only pick up 20-30 HP, I'm going to be highly ticked off! LOL

 

Do you like how it runs, or are you concerned about a dyno number? Personally I'd have a 90MM throttle body and 1 3/4 headers minimum, good ones, and a full 3" exhaust. The A/F ratio seems high also...

 

The car was tuned on the road with tweecer to right at 13:1 AFR and has manners but some bucking below 1500rpm.

That alone tells me there's something off in the tune. The stalling while letting out the clutch didn't look too good either. That's a mild stick in there for a 408 and you should be able to let the clutch out with no throttle at all.

Recently had a customer down under who changed the O2 sensors in his HSV and picked up 26 RWHP at peak. (402 to 428) The little things will bite you in the butt every time.

 

You do cams for our HSV's?

 

Your dyno sheet shows you are not 13.0 A/F, who tuned the car? How much timing do you have?

 

I thought bucking below 1500 rpms was normal for a larger than stock cam shaft. Also, your throttlebody,headers and h-pipe are killing you. FWIW I have a mild FTI cam with 1-3/4 headers, 3inch pro chamber and cat back, 90mmTB on my 408 and it makes decent power..

 

torque takes a huge dive at 5K, may we assume Ed supplied the valve train?

 

torque takes a roller coaster drop at 4.8k, may we assume Ed supplied the valve springs?

 

Scaling differences may make it look worse than it actually is. Notice TQ is on the right, HP is on the left. I HATE when the dyno operator prints sheets like that.

 

Assuming a 15% drive train loss, 520 crank HP = 442 RWHP. Aren't you right there? The bucking should be easily tuned out. The drop in TQ is interesting.

 

Just getting back on the computer. Thanks for all the responses. I’ll try to address in order.
The MAF is new so it’s not dirty.
I installed the cam straight up. There was no direction to do anything else.
It’s not a max power effort hence the cam and exhaust but I still expected more.
I’ll try adjusting the timing some more up top. I’m going to check compression/plugs again, put a 125hp and go back.
For the bucking I haven’t got into tuning it too much but it runs so much better than It did with a stock calibration with just injector, displacement, and MAF info put in. I’ll add some fuel at low rpm cause I am running it fairly lean down there and at cruise for mileage. Might add some more timing down low as well. Idle is rock solid around 1000rpm.
The O2 sensors are good. They only have a few thousand miles and their outputs look to be consistent for left and right in my datalog.
I went into my datalogs of the dyno runs and my wideband (which is new) shows just over a half point less throughout as compared to the dyno readout
Rpm AFR
3500 13.19
3700 12.49
4000 12.64
4200 12.66
4500 13.01
4700 12.63
5000 12.84
5200 12.74
5500 12.40
5700 12.76
Richer at higher RPM. Same difference from the dyno readout with nitrous. They had their wideband in the same tailpipe my wideband is in (in the longtube collector).
Here’s the timing I have set with the Tweecer (base timing 10det):
1000 14 deg
1800 23 deg
2150 26 deg
2600 27 deg
3500 27 deg
5000 30.50 deg
16383 30.50 deg

I took out 5 deg for the nitrous pull because the guy I bought it from said it had a 150 pill and I didn’t check. Really only needed to pull 1.5 deg.
The springs are stock AFR 205s but are plenty as my recollection is this cam is around .560 ish.
The torque drop off is deceptive because the scales are different. Notice that it is 420 rwtq at 5700 rpm though if you are looking at the HP scale it looks like it is 300.
520 crank = 442 rwhp so I’m almost 40 off. The last was with nitrous.

 

520 crank = 442 rwhp so I’m almost 40 off. The last was with nitrous.

Yeah, I need to learn how to read better. For a data point, my AFR 205 408W makes 440 RWHP (5,600 rpm) and 445 RWTQ. That is with the Comp XE282HR cam, 1 3/4 long tubes, Victor Jr with 775 Road Race Demon carb and 3 inch exhaust with Cats. Also, the combo does not like anything over 30 degrees of timing.

 

How do you know the Dyno is calibrated right ?

And you get all kinds of numbers from one dyno to the next ...

 

I think this is a good observation. looking at the dyno graph, torque and hp should intersect at 5252 rpm. doesnt look like it to me?

 

I don't...but I dyno'd my 352 there and it put down 370/395 with lesser parts and 56 less cubes

 

And my buddy took his AMG E63 and it was right where it should be stock

 

Did it ping with more timing? How did you come to 30.5? Why the .5?

 

Don't the AFR 205s come with a solid roller spring package? Is this suitable for a hydraulic roller setup?

 

What do you mean you installed the cam "straight up", do you mean dot to dot or on its intake center line.

 

any other dyno places close by? Might be just a peace of mind to double check.
ex: my car when all was done should have had about 345-375 hp range I thought. Dyno and I barely got 245 at the wheels. When I politely asked if this could be right, his response was yep, dyno's dont lie. I'm just not as fast as everybody thinks. ok, never liked dyno's any way so off to the track I go. On small 235/60/15's I run 11:40's. His reponse was wow your nitrous works great. yeah imagine that with it not even hooked up. Takes little more then 245 to run 11:40's and my car is not gutted at all.

 

I put the cam in dot to dot. These are the older AFR 205s when they came with hyd roller springs, 1.550” Roller Dual Valve Spring w/ dampner (.670”).

I had no pinging even when I added 3 deg from 3500 rpm up (so 33.5) but lost 4 hp. I know some folks lock it in at 33 spout out for racing. I never went to ping and backed off but as its a DD I need it to work at 110deg outside as well. I arrived at 30.5 through driving and datalogging and just felt that was the best torque seting. With only 3 runs on the dyno (didn't pay for tune time) I went with what I had dialed in then made the 3 deg jump to see the difference.

 

I think the last few cams I have ran (including FTI) was not even close @ dot to dot, was like 5* off on Ed`s FTI cam. Did you use a degree wheel at all ?

 

Your springs are not very good. I think Tmoss is right, I am blaming valvetrain now.

 

Don't belive either WB. They were .5 off from each other.

Tune it so that it makes the most power. Still think you have too much timing.

Just because you can't hear it rattle dosn't mean that it is not. I have never heard mine rattle but I have had it slow down at the track with to much timing in it.

Tim

 

To win races you want lowest timing for best torque. In a street car you want a little less to survive a bad tank of gas. If you were on the dyno to get tuned and the operator didn't shoot for that, take your car and money somewhere before they blow it up.

The bucking under 1500 rpm is not normal, and FFS don't bump the nitrous shot up until the N/A stuff is sorted out.

How did you adjust your rockers? Are we assuming right that Ed gave the thumbs up on those springs? Did you log manifold vacuum during the run and if so, what did it look like?

 

The small headers and restrictive exhaust are definitely hurting power. I've also proven that my 408W combo does more with less timing.

I also run an FTI cam, and on the sheet is the statement "Degree this camshaft using the specs provided on this sheet", nothing about just installing it "dot to dot". I ended up having to install my cam 2* advanced to hit the correct timing events that Ed spec'd for it. Degreeing is so you can account for machining imperfections in crank keyways, timing sets, etc...

Attention to the details is key to optimizing.

 

I believe this is right, exhaust is quite small. My cam needed to be installed 2* advanced also for it to be right too.

 

intake too small, tiny headers