Car dynoed today

#1

:frowning: Well Im the new guy here. Gut my provisional and had my first race at summit last month. I had been thinking the car was down on power but I had done most of my HPDE’s in a 400 HP Cadillac CTSV and assumed it was just me. In the race the pack left me like I was draging an anchor and I was thinking of early retirment if i couldnt do better than that.

Well I had the car dynoed today at All Aspects Motorsports in Chesapeake VA on there dynojet. And from what I am reading in this forum I am pretty much hating life:angry: .

Run HP Torque
First 120.66 114.92
Second 118.44 114.4
third 118.33 117.25

Any words of wisdom fro you veterns ot there???

I do have another motor but spending 4 grand plus to have it freshened at a machine shop and then having it swaped by a mechanic will realy hurt my feelings (and my wifes too if you know what I mean). Puting another old motor in without having it gone thru doesn’t make sense either. But you guys are making 150hp plus. Im not even in the game.

#2

Is the catalytic converter still on and oem exhaust? if so that is a big part of the problem. Although I am not sure that is all the problem.

Other things to consider;
was the AC on or has it been removed?
oil are you running 30 w5 or something close?
wheels are your running stock wheels which are heavier than we use to race?
do a simple compression test and leak down test before scrapping the motor

I think it is extremely rare for a junk yard motor not to put out 145hp, a number of guys including myself can sell you a motor that will do 147 to 150 in hp and torque. I have an extra and it won’t cost anywhere near $4000. Also swapping the motor is easier than you think. I know very little about mechanics and could do it myself with a little help in about 6 hours. Finally just freshening the head will cost about $1000 or so and should fix any remaining problems.

#3

Rick - So you are in Chesapeake? Mike and I also live in Chesapeake, VA. We bought a junkyard motor and did the swap about 2 months ago (spun a rod bearing at VIR in July). Spent $500 on motor, $250 to freshen head, $200 on gaskets, and as Carlton said, did it on a weekend. Car made over 150 hp/150 torque on the dyno at Nationals in September and car finished 5th in final race.

Give us a call if you want to come by and do some diagnostics 757-483-3794.

Ed

#4

I personally would figure out why the motor is down on power before doing anything else.

#5

Rick if you would like a comparison my buddy owns Millennium Racing Development and you could put your car on their dynojet.

#6

We also have a collection of ECU’s. Did you check the compression? Do you still have a catalytic converter on the car?

#7

No converter, no AC, Wheels are not stock. Exaust has been redone. My last (third) run was with the ECU from my spair motor. still 118 HP.

I am actualy in Norfolk (live in west Gent).

I talker to the guy at Pegasus (user to be Phase 1) machine shop about going thru my spair motor. He to has a dynojet and I thought about puting the car on his machine for compairison.

The spair motor was out of John Feltons old car. Cabeto said he had driven this car and the motor was strong.

#8

What did the A/F ratio look like during the dyno run?

Have you done a compression & leak down test? If so what were the numbers?

There are several reasons for an engine being down on power that doesn’t require a rebuild to fix. It would make sense to me to determine the reason for being down on power before going for a rebuild.

#9

Im not real up on A/F but the graf shows it at 15 + or - through the rev range until about 5600 rpm’s. From there it drops to about 13 at red-line (6300 rpm,s). Do these numbers make sense.

#10

Stoic ratio would be 14.7. That provides the best efficiency but not necessarily the best power. I’d say the engine is running a bit on the lean side up to 5600rpm. There are a number of folks that say that 13.3-13.5 is ideal for power and it sounds like you are there above 5600rpm. The question would be why the shift above 5600rpm…

An aged O2 sensor, bad AFM, or bad DME engine temp sensor are the first things I’d think of as an explanation for the A/F curve. But I don’t know if they alone explain the power curve. I’d do a compression and leak down test as the next step in figuring out how to solve the problem.

#11

Thanks to Ed Davidson, we got a compression test done today.

     1    2    3    4    5    6

Dry 155 150 145 155 155 150
Wet 160 150 150

Only did 1-3 wet
Acording to the repair manual 145-155 is good but Ed said his read higher. Input???

#12

The compression numbers look pretty decent. At least good enough to not be a cause of the low dyno results. I think you need to be looking into engine management issues.

#13

Do a leak down test - you can gather much more information about state of the engine.

Regards,
Igor

#14

Engine sounds fine. AFR is way off. I’d start by testing the TPS (throttle position switch) per the Bentley manual. If that passes, coolant sensor. You said you swapped ECUs, right? Let us know if those two items are in check.

#15

I would swap the Air flow meter with a known good one too…

#16

Yes the ECU was changed.

Quedtion here; could this be an injector problem? Could the injectors be worn or clogged restricting fuel flow?

I have another air flow meter I can put on.

I think at this point I am going to take it to Palister and let him test the thing.

#17

Well between Dave Ed and I, we have checked just about everything that can be checked. We put on a new air flow meter, everything else checked ot OK.
The new Dyno numbers are in and I now have a screaming 132HP.
I guess she is just tired.
Looks like time for a rebuild and swap. The good news is I have until Feb.

#18

Rick - one last little thing… are you sure the throttle cable is giving you WOT when the pedal is matted? I have seen professional open wheel race teams overlook this simple cause for poor performance.

#19

We did have an issue with that but the last guy that dynoed my car caught it and fixed it before the dyno. This may be where the extra 12 HP came from. And yes alot of people missed it included me.
At any rate I apreciate all the input, I am out of ideas.

On another note is anyone doing the Trackdaz DE at VIR on Monday the 19th?

I borrowed a buddies chipped ECU that he said should give me 12 to 15 more HP (he is a BMW mech. at Checkered Flag). I am looking forward to driving the car with somthing close to the power it should have.

After that I guess its time to pull the engine.

#20

I know pallister will be there with his E30.