new motor question

[james3340]

Here's my question, I purchased a new motor and I put bbk Lt on and msd spark plug wires and the car already had a flowmaster exhaust on it when I put it on the dyno they told me it only made 277 to the wheels. When I purchased the motor they said it was a 440 HP motor I know that there will be some loss of HP but to me that is a really big gap. Could it be that the headers are boiling the clutch fluid and the clutch is not engaging all the way I'm at a loss here. I'm getting ready to put a tick mc on the car with a monster stage 3 clutch and a SLP loudmouth 2 exhaust. Here is the specs of the motor and any help would be appreciated.

Short block components

TMS Hypereutectic piston set 3.898"
TMS performance rings
Blueprinted GM block LM7 core
GM connecting rods TMS remanufactured cores
GM Nodular turned and Balanced core
King racing rod bearings
King racing main bearings
Thompson Motorsports single piece racing cam bearings
Long block components

317 casting Angle milled heads Thompson Motorsports remanufactured
TMS Custom ground cam .578 .587 226 232 115+4
PAC 1218 springs
Chromoly pushrods
Thompson Motorsports head studs
MLS head gaskets
Melling high pressure oil pump
Thompson Motorsports ls7 lifters
GM rocker (trunion upgrade available on these cores at an additional $299)
lifter trey set ls2
ls2 timing chain
ls2 cam sprocket
1 year unlimited mileage warranty

Max HP rating of 450.

[Whamhammer]

Here's my question, I purchased a new motor and I put bbk Lt on and msd spark plug wires and the car already had a flowmaster exhaust on it when I put it on the dyno they told me it only made 277 to the wheels. When I purchased the motor they said it was a 440 HP motor I know that there will be some loss of HP but to me that is a really big gap. Could it be that the headers are boiling the clutch fluid and the clutch is not engaging all the way I'm at a loss here. I'm getting ready to put a tick mc on the car with a monster stage 3 clutch and a SLP loudmouth 2 exhaust. Here is the specs of the motor and any help would be appreciated.

Short block components

TMS Hypereutectic piston set 3.898"
TMS performance rings
Blueprinted GM block LM7 core
GM connecting rods TMS remanufactured cores
GM Nodular turned and Balanced core
King racing rod bearings
King racing main bearings
Thompson Motorsports single piece racing cam bearings
Long block components

317 casting Angle milled heads Thompson Motorsports remanufactured
TMS Custom ground cam .578 .587 226 232 115+4
PAC 1218 springs
Chromoly pushrods
Thompson Motorsports head studs
MLS head gaskets
Melling high pressure oil pump
Thompson Motorsports ls7 lifters
GM rocker (trunion upgrade available on these cores at an additional $299)
lifter trey set ls2
ls2 timing chain
ls2 cam sprocket
1 year unlimited mileage warranty

Max HP rating of 450.

What are you using for intake, throttle body and tune?

[james3340]

My buddy tuned it for me with HP tuners I have the stock tb and intake but have the air pump and egr deleted

[pajeff02]

You are less than what a stock engine equipped car makes. Is the 277 a "corrected" number? Are you monitoring A/F? Any signs of clutch slippage on the street?

[james3340]

The air fuel was fine and I'm having some issues with the trans right now not wanting to go into 3rd but at the time there was no problems on the street

[SMWS6TA]

Was the shop you got the engine #'s was that at the crank or at the wheel? Crank numbers will always be higher than RWHP.

Several things effect RWHP #'s in addition to the engine. Depending on the drive train (A4 or M6), rear end, gearing and wheel/tire size will all factor in to it. Also the type of dyno too as well as altitude (Actually air density). Mustang dynos seem to always read lower numbers over dynojet. Not to mention a tuner can also effect it.

General rule of thumb for stock rears is on A4's about 20-25% and for M6 17-23% parasitic lost for RWHP.



Also with M6 cars a dyno pull should be in 4th gear.

[james3340]

Its a m6 with stock gears its a 99 ta ws6 and it was a dynojet. Those numbers are to the crank but the thing I don't get is I'm making less HP than a stock car. I added it up for 16% loss and it should be a 60 HP loss.

[theorangeguy]

Was the shop you got the engine #'s was that at the crank or at the wheel? Crank numbers will always be higher than RWHP.

Several things effect RWHP #'s in addition to the engine. Depending on the drive train (A4 or M6), rear end, gearing and wheel/tire size will all factor in to it. Also the type of dyno too as well as altitude (Actually air density). Mustang dynos seem to always read lower numbers over dynojet. Not to mention a tuner can also effect it.

Rule of thumb for stock rears is on A4's about 20-25% and for M6 17-23% parasitic lost for RWHP.



Also with M6 cars a dyno pull should be in 4th gear.

Going from 440hp to 277rwhp is a pretty steep drop tho...like having a spark plug wire unplugged kind of steep lol If the 440hp estimate that he got is correct he should easily be in the mid to high 300's. Even at 25% drive train loss, that's still mid 300's "which I think his set up should be more than that" but I went with the highest % just for kicks.

James is your car an auto or manual?

[james3340]

Its a manual and I checked all spark plug wires they were all on. I made sure to check all common things I could think of before posting lol. But there might be something I am over looking so I'm open to all suggestions.

[theorangeguy]

Its a manual and I checked all spark plug wires they were all on. I made sure to check all common things I could think of before posting lol. But there might be something I am over looking so I'm open to all suggestions.

If everything is buttoned up and you are confident that the motor is legit, the only thing I can think of right now is that your clutch is slipping in a big way...if you are still running the stock clutch and your car is north of 75,000 miles and 450hp the odds of it slipping are pretty high which will obviously throw your dyno numbers off but a tuner can usually tell when that is happening. Usually anyway...

[james3340]

The clutch was a centrrforce dual friction it was put in about a year before the motor was put in. The motor came from Thompson motorsports so I trust them.

[theorangeguy]

The clutch was a centrrforce dual friction it was put in about a year before the motor was put in. The motor came from Thompson motorsports so I trust them.

I've heard a lot of mixed reviews about the centerforce clutches...that also makes me wonder if its the clutch even though it isnt that old.

[james3340]

Same here I have heard some good and some bad that's the reason I got a stage three monster clutch I'm going to put in there that way I know it can handle the power and I still have room to add more in the future.

[theorangeguy]

Same here I have heard some good and some bad that's the reason I got a stage three monster clutch I'm going to put in there that way I know it can handle the power and I still have room to add more in the future.

I think you are on the right track. I say drop the clutch in and go from there to rule it out one way or the other...

Does your car slip in RPMs at all? You can check it by going into a high gear at low speed and seeing if the RPMs shoot up "like 4th or 5th gear at below 30mph and push the peddle down"...sometimes that will show if your clutch is slipping but it doesnt always show it.

[james3340]

No it doesn't do that but then again like you said it doesn't always show it. But I'm hoping this is also the problem with my trans not wanting to go into 3rd at high rpms and sometimes this happens with 4th.

[Firebirdjones]

From an actual engine dyno to a chassis dyno as installed in the car I usually see 100-150 HP difference depending on the combiniation. You also have to throw in the variances of the dyno's used. Mustang chassis dyno's use a different method of measurement and appear more stingy compared to others for instance, plus other variables like correction factors, etc...

The reason I see such big gaps is because on a bare engine dyno there is nothing but the engine up there, no air cleaners, no accessories, in most cases they don't even turn their own water pumps, there usually isn't an exhaust system and in some cases you end up using their dyno headers which work better than chassis headers as installed in the car.

Then the engine is installed in the car, turning an AC compressor, an alternator, a water pump, a smog pump, you have a complete exhaust system, an air intake system, plus you have to turn things like a clutch or converter, the transmission, driveshaft, rearend, the wheels and tires etc.... All this sucks HP.

I have 2 cars here that are examples of this, and both saw a drop of just over 100HP on one and almost 130HP on the other. The difference is drivetrain losses, one that is more severe because it has a looser converter in it.

So I think this accounts for alot of what you're seeing. If your clutch was slipping on the chassis dyno you would have certainly smelled it, and usually see the smoke as well. However even with all that said, I do believe your engine combination with that cam should make more than 277 RWHP, even with a stock head. No mention of any head work or the size of the engine, that would play a factor. The LS1 intake might be holding you back a little. I would go back and check the computer tune, the AFR, check the other simple things and see if you can find something out of the ordinary.

How does the car run and drive? Is it snappy or does it struggle to get out of it's own way? Did that engine shop actually provide you with a dyno sheet before you installed it in the car or is this just a "projected" number??

[james3340]

The car runs really good its very responsive and everything that's why it has me puzzled

[Firebirdjones]

Then probably likely that either the number given when you bought the engine is a "projected" number based off other engine builds they have done, or the chassis dyno you were on was a Mustang dyno that are typically stingy. If the latter, a Dynojet would likely put you well into the 300's.

Really need more information for accurate answers, we could shoot around the possibilities all day.

[james3340]

It was a dynojet dyno. They do have this engine for sale on eBay so it is probably a projected number from other engines that they have buily .

[pajeff02]

You live anywhere near a drag strip?