Built Motor Low Dyno Numbers

[thatonenozz]

Wanted to get everyone's thoughts on this. Just did an all out N/A build and it didn't make the kind of power I had anticipated. It also made peak power and started rolling off a little lower in the RPM range than I thought. Here's the specs of the motor and the dyno sheet.

- Sleeved Coyote Block bored to 5.2L
- 12.75:1 compression
- Slawko Racing ported heads
- Comp Stage 3 N/A cams
- TFS Valve Springs
- CJ Manifold, Twin 65 TB, PMAS CAI

I mean the car feels plenty fast, it's just that I've seen guys make about what I did doing only cams, headers, and CJ manifold so I was expecting maybe another 50hp out of it. IDK :shrug:

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[5.oh]

Do you have the airfuel graph?

 

[thatonenozz]

Here's the AFR graph of the hit from the datalog file. I'm on E85 also I forgot to mention

 

[Angry50]

what did it make? have you tried talking to the tuner?

 

[thatonenozz]

527/429. Is the graph showing up okay? We had it on the dyno and the tuner said all the logs looked good so he wasn’t too put off by the numbers. I know he was trying everything and I trust him. Im pretty sure it’s a mechanical limitation at this point but looking for ideas of where to start

 

[BluByeU]

527/429. Is the graph showing up okay? We had it on the dyno and the tuner said all the logs looked good so he wasn’t too put off by the numbers. I know he was trying everything and I trust him. Im pretty sure it’s a mechanical limitation at this point but looking for ideas of where to start

I don't see the graph.

 

[thatonenozz]

Let me try again

 

[thatonenozz]

Attached dyno graph for anyone who can't see

 

[Anthony 05 GT]

That doesn't look bad to me.

 

[F1scamp]

If the heads weren’t the original restriction point, you wont gain much from porting. What did they flow before and after? Really the only performance difference would be the 1.75 points of compression, and I would be surprised if that would be more than 5-10hp.

 

[thatonenozz]

Here’s the before/after flow data Slawko published for their CNC program on the 15+ heads, though I can’t say whether or not mine were individually flowed. Likely not. I guess I really expected more than a 5-10hp gain from the compression bump. The extra .2L of displacement is pretty small as well obviously. Dammit I guess I just had higher hopes. Is compression too high to change my mind and turbo? :lol:

 

[Anthony 05 GT]

That's some high compression for going turbo. You wouldn't get away with more than somewhere south of 10 psi...guessing about 7 psi. After reading again I assume the dyno run was engine only and not at the wheels?? If so, it does seem low. If it is at the wheels maybe you need someone more familiar with this system to tune.

 

[F1scamp]

When already starting at 11:1 compression, you aren't going to gain much with a bump up. There is diminishing returns the higher you go. I doubt the heads were a restriction flowing 320cfm with 302cu in. Gaining 16 cubic inches on a motor that makes about 1.44 hp per cubic inch is only 20-25 hp. Get some custom thicker cometics and slap a turbo on it.

 

[thatonenozz]

That's some high compression for going turbo. You wouldn't get away with more than somewhere south of 10 psi...guessing about 7 psi. After reading again I assume the dyno run was engine only and not at the wheels?? If so, it does seem low. If it is at the wheels maybe you need someone more familiar with this system to tune.

This was at the wheels. Lund tuned it and I’ve seen a few of these he’s pumped out so I’m pretty confident in his tuning. I’m happy with it because the car feels awesome, I was just expecting more is all. Sounds like I had too high of expectations for what I was building.

When already starting at 11:1 compression, you aren't going to gain much with a bump up. There is diminishing returns the higher you go. I doubt the heads were a restriction flowing 320cfm with 302cu in. Gaining 16 cubic inches on a motor that makes about 1.44 hp per cubic inch is only 20-25 hp. Get some custom thicker cometics and slap a turbo on it.

Yeah you’re probably right I guess the numbers don’t seem too far off. No turbo for me. I came from a Paxton setup but all I do is road course the car so the power was always too much and heat was always a problem. 527 N/A is plenty of fun in the corners. Thanks for the insight!

 

[Anthony 05 GT]

Well, if that's at the wheels and Lund tuned it I don't think it's bad at all. 5.2 liters with those numbers is pretty damn good. More power than a GT350 and pulling hard to 7300. Do you know which Lund rep tuned it? Also, how are those stage 3 cams to handle on the street?

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