All AFR/FTI/EDELBROCK guys in here NOW!!

[DARK-5.0]

What the hell is wrong with my motor. I got it dyno tuned today and this is all we got out of it. This is now the second time I've only made around 270rwhp. This time on a rebuilt shortblock. Heres a run down of everything I have done to it.

Rebuilt shortblock-stock bore, forged pistons, rods, stock crank.
AFR 165 heads
FTI cam
Edelbrock performer intakes
C&L 76mm maf - I think is the problem
BBK 70mm tb
24lb injectors
190lh fuel pump

I really think its the maf. One the last shortblock we couldn't get it a good afr because the maf was acting up. I buy new electronics for it to see if that helps. It seemed like it did, but looking at the graph you can see the drops in the torque curve. Also while just driving around it seems hesitant a little when you mash on it. Then it wakes up and pulls. How does everyone else make 300rwhp with these combos and I can't. You guys gotta help me out.

Base run-

Final outcome-

Jeremy

 

[stprorolla49]

yea, C&L mafs have been known to be finicky on our cars....maybe give a 75mm Pro-M a shot???

 

[1slow95]

I've heard the C&L's only seem to work right with the stock air box setup. I'd say give that a try, or maybe switch to a Pro-M.

 

[DARK-5.0]

Well through some other research. I'm looking at blaming the maf, the pushrods, and the computer. The maf because its a piece of ****. The pushrods because the wear pattern showed them being a bit short (eventhough fti put the whole combo together) and the computer because pih conversions show such an improvement tuning wise.

Jeremy

 

[blksn955.o]

I would wait to get a MAF before saying the 94-95 eec is junk...without a tune/tuner yes it sucks...with one it does not.

The MAF would be the thing I would check as far as elec. sensors go.


I am guessing a tune has been done to some extent?

 

[DARK-5.0]

Thats what this thread is about. I got it tuned today and it only made that much power. Its fully tuned, the afr is perfect at 13 and its not making the right power.

Jeremy

 

[VibrantRedGT]

The graph isn't choppy for a MAF issue until the end there. Hopefully it is the MAF but its pretty off for just that. Any other members in your area you could borrow a MAF from? A Pro-M 80MM would be perfect.

 

[final5-0]

Well through some other research. I'm looking at blaming the maf, the pushrods, and the computer. The maf because its a piece of ****. The pushrods because the wear pattern showed them being a bit short (eventhough fti put the whole combo together) and the computer because pih conversions show such an improvement tuning wise.

Jeremy

What are you doing for tuning the combo at this time?

Fuel ratio looked pretty good to me

What different kinds of spark values were you working with during the pulls?

If the pr's are too short, you are not getting the amount of lift you should and that could cause a loss of performance.

The maf could be holding you back I guess. Of all the meters out there, the C&L and ProM 75mm bullet have had than their share of negative comments from various peeps on these forums over the years. Lately, some have said the larger ProM meters have had an issue or two
These days Jeremy, I don't know what I would do if I needed a meter.

Maybe a Lightning meter
but
you can't run it in cheat mode so a tune is a must with that choice.

Now as far as your pcm ... it just needs a tune

The fox pcm retro-fit is something I just can't buy into
so
I won't even go there

Grady

 

[WhiteDevil]

Especially when it comes to making power, the PCM just controls A/F and timing WOT tuning i so simple its not the comp thats robbing your power.

 

[DARK-5.0]

Thanks for the response. Theres a lot of talk going on in a local forum and we're looking into the above. I've emailed Ed about the pushrods and what he thinks. We're also looking into having my cam straight up instead of degreed. My thoughts now are replace the pushrods if needed and go to a lightning maf. I'm gonna need a tune after the pushrods anyways, plus if I switch computers.

Jeremy

 

[Killercanary]

Jeremy, lets start with the basics.

Are you 100% absolutely sure you degreed the cam correctly for the weight of the car?

There are many things that can affect pushrod length, so it should always be checked. If they are too short then it should be one noisey SOB. Are you sure they are not too long? How much preload do you have on them? When you rebuilt the shortblock, did you have the block decked? Have the heads been milled? What's the compressed thickness of the gasket? What length of pushrods are you running? I needed 6.300" on my car.

How are all of your gaskets, openings, etc. Are they all "matched" so that you do not have any "lips" and such that might cause airflow restrictions?

Is your TB blade opening completely when the throttle is at WOT?

I think the problem lies in these questions. Based on that nice flat AF ratio you have, I don't think its due to the MAF. How much total timing are you running and at what RPM does it come in full at? Is the filter protected from hot underhood air?

 

[95WhiteVenom]

Paul made very valid points there I would definately also look into getting a Pro-m 80mm. The lightening 80mm dont flow as much. I've been told by every place I went to before getting my pro-m not to get a C&L.

 

[Killercanary]

I'm going to go out on a limb here and say this. I hate C&L meters and I will NEVER own one, however... at this time I do not recommend dropping big money on a MAF until you have checked and rechecked everything else. The MAF tells the EEC two things; how much air is coming into the engine, and the load placed on the engine (which is a derivative of the the amount of incoming air). Your AF looks pretty good, so the MAF and EEC are working in synch at least in terms of matching the incomming air charge with the proper amount of fuel. And since load is derived from the amount of air entering the engine (along with TPS, RPM, etc) I think its safe to assume at this point that this isn't the main reason you are missing so much power.

If it was my car I'd start by taking off the inlet to the TB and have someone push the throttle to the floor and see where the blad ends up, also check the transitions between the TB and elbow, the elbow and the upper intake, the upper intake to lower intake, and the lower intake to the heads. There should not be any lips, gasket material in the way, etc. All should be a very smooth transition. Bumped and lips lead to turbulance and its amazing how much this can effect horsepower, just ask anyone that has studied fluid dynamics.

Once all these are checked (that is an easy thing to do... always do the easy/free stuff first!), then you need to look into the pushrod length (do you have stud or pedestal mount?), and ultimately you may need to recheck the cam timing events. Other than that there isn't a whole lot more that can limit power production. If you had a problem with fuel, it should show up in the AF graph so that only leaves the air volume entering the combustion chambers.

Did they datalog your timing on the dyno? Are you sure you are getting full advance? Next time on the dyno you may want to try manually setting the dizzy to ensure that you do not have a problem in the EEC or elsewhere that isn't allowing for full timing advance. I'd lock it at 32* and see what the power does, you may need more or slightly less total.

I know it sucks finding gremlins, but don't get too frustrated yet, you'll figure it out.

I never posted this before but right after I put my car together for the first time I got into a postion where I had to go and go QUICKLY in my car. I ran it through all the gears and the thing was a DOG! I mean it felt as slow as stock and the car literally wouldn't pull above 110mph. I thought I had blown it up. I never did find out what I did but that weekend I spent the time re-adjusting my rockers and the problem went right away. When I say readjusting though I mean I went from milled pedestals and stock length pushrods to 6.300" rods, stock height pedestals, as well as shims. I think some of my valves may not have been seating fully at high rpms and that's why it wouldn't pull anymore.

 

[Killercanary]

Also, after you check everything you can, you may want to put a vacuum gauge as close to the heads as possible... about the only place you could is in the upper intake I suppose. What you will want to look for is vacuum as the engine pulls through the RPM range. Under WOT there should not exist a vacuum unless there is a restriction somewhere. I think this is a long shot but its something to think about for down the road.

Edit, if you do this try and find a gauge that has the smallest units of measure possible since the vacuum you see will not be much. If the gauage starts at like 10 and goes in increments of 5 from there its not going to help much.

 

[YEAHLOH95]

how many miles are on the new motor? maybe it needs broken in more ??

 

[Stangfreak95]

Yes there's something wrong there with your stuff. I also would of NEVER used a C&L meter but thats my opinion. It could be your problem. But Paul pretty much brought up all of the good possibilities so you might look into those also.

About the cam, did you degree it the RIGHT WAY from the start ? (Ed must of told you something about that)

 

[Zero Signal]

Yeah, I'm with Paul. I agree with starting with the basics. Do a compression check, leakdown test and vacuum test.

If your A/F ratio is right, then there is a good chance it has nothing to do with your fuel system at all. So forget the MAF. Take a really good look at your valve train. Getting a couple clearances off can easily kill your power! Especially if you had the block deck milled, you may have excessive preload (hence low compression) like Paul was saying.

On the cam . . . you shouldn't have to degree it. Don't the FTI cams come with a built in 4° advance, in which case, just line it all up at the timing chain at TDC then check your ICL with the cam degree wheel and dial caliper setup. It will probably be right on unless you accidentaly skipped a tooth on the timing chain.

When I put in my cam, I just aligned the dots on the pinion and sprocket @ TDC then refered to the cam sheet for the ICL (106° @4° Adv. for me), setup the degree wheel with 0° @ TDC and it was dead on perfect. There was no 'degree'ing' involved.

 

[zenboy99]

On the cam . . . you shouldn't have to degree it. Don't the FTI cams come with a built in 4° advance, in which case, just line it all up at the timing chain at TDC then check your ICL with the cam degree wheel and dial caliper setup. It will probably be right on unless you accidentaly skipped a tooth on the timing chain.

By degreeing it he means getting out a cam degree wheel and dial indicator to make sure all the cam events that are happening at the valve are what the cam spec sheet states. I degreed my cam, duration values were off 1/4 to 1/2 a degree wich is normal for most cams. Ed suggests degreeing the cam to make sure that comp didn't send you the wrong grind. I used this one from Summit, part # SUM-G1056

Also check your exhaust, it may sound stupid but a friend of mine had a piece of metal lodge in his H-pipe that was causing an obstruction and killing power.

 

[Zero Signal]

I always thought, degree'ing the cam was actually setting it, otherwise it's just checking it. But that's what I meant

 

[zenboy99]

Yeah, I had alot of confusion with that too when Ed told me I should degree the cam (piston to valve clearance was close). He was patient enough with me to talk me through the procedure.