Texas Speed 427 low NA power

[morepowerjoe]

Originally Posted by FasNuf

EDITED: The EXECUTIONER from TSP is a re-sleeved LS3 block punched to 427

Ok I looked it up. Thanks. He said he is using a stock intake and throttle body on top of all that. It's probably not doing him any favors I wouldn't think?

[Pkeen]

Yea I wouldn't be very happy with those numbers either, my 416 made 515rwhp and 500rwtq. Above 500hp from 5300-6500, and I'm still running the stock unported heads,intake,injectors and tb.

[RupertPupkin]

Originally Posted by morepowerjoe

Ok I looked it up. Thanks. He said he is using a stock intake and throttle body on top of all that. It's probably not doing him any favors I wouldn't think?

Ls3 intake and tb is good. They can move air.

[Ashen L99]

Could just be the dyno. Could be the tune. Could be the motor. Did you baseline it before the 427?

LS3 mani isn’t doing you any favors on that combo. Needs hi-ram or the like, would probably pick up some steam. If going pro charger, no reason not to swap intake manifold.

[joshnmn]

Originally Posted by RupertPupkin

Ls3 intake and tb is good. They can move air.

Agreed. Both move plenty of air for your setup. There are others that will move the RPM band up, but average HP numbers sometimes fall.

After checking out the oil and making sure it's not hurt, might want to check out another tuner. Like getting a second opinion...

[kennyry83]

Here is the dyno pull, makes me sad lol. Gonna be getting in touch with TSP today.

And no I didn't base line it before the engine and everything else, it was just a stock LS3 so seemed kinda pointless to baseline off a stock car. Nothing is the same except the intake, throttle body, trans and the body.

Don't think it's anything in the tune, Andre with ABEL Racing is pretty top tier tuner. A lot of big name local guys go there as well for tuning such as Shawn Ellington with 187 Customs (Murder Nova).



But ya, its resleeved (Darton Sleeves) and bored to 4.125.

[RupertPupkin]

I say it could just be the dyno that's it's on.. I know when I had my FBO sbe with ECS 1500 dynoed it produced 750 with e85 on 1 dyno (tuner was kind of wish washy). Had it retuned through a different shops and it made 800 on theirs.

Now with my 402 and ecs with a different builder and great tuner it pushed 730 w/ e85. In my head it would be higher bc it's a bigger engine, but was kind of heart broken in. a way. It does feel faster tho. Regardless, your setup shouldn't be falling flat at 5900rpms.

Before I went SC, I had similar cam specs with my sbe ls3 and that thing was revved up til 6800, and that's when the power tapered off. Hope you get it straightened out, and I know it's frustrating especially shelling out some dough.

If it was a bent rod or issue with the rockers, I would think it would throw codes... maybe maybe not.

[Batmanntexas]

Can you provide additional specs on the PRC 260s? Seems to me that it would be hard to maintain a 10.7:1 CR with a -11cc dished piston...unless the head chamber is pretty small. Additionally, what head gasket did TSP use, thickness wise?

If indeed, the CR is less than the 10.7:1CR, then your numbers may be pretty close for your combo NA.

-Scott

[Batmanntexas]

What did it make for torque?

[kennyry83]

Originally Posted by Batmanntexas

Can you provide additional specs on the PRC 260s? Seems to me that it would be hard to maintain a 10.7:1 CR with a -11cc dished piston...unless the head chamber is pretty small. Additionally, what head gasket did TSP use, thickness wise?

If indeed, the CR is less than the 10.7:1CR, then your numbers may be pretty close for your combo NA.

-Scott

68CC, .051" head gasket - I double checked them when I got the build sheet lol.

The dyno sheet attached is my brother inlaws LS3 in his 71 C10. Its a 140k stock LS3, freshened up with a stage 2 TSP cam and a 6l80 auto. Same dyno, don't think its the dyno.

Although I did contact my salesman, was super cool and is looking in to it and is going to get back in touch with me.

[WHAMMO]

You are not going to make big bumbers with stock LS3 intake/TB. 102mm TB/High Ram would increase by 100hp.

A stock LS7 has around 445rwhp average, that is with a LOT better intake, Ti rods and a lot more better rod/bore/crank combo. 11:1 comp ratio too. The stock LS7 heads have a lot better intake port+the LS7 int port are just better for bigger sir flow for a 427. You have low compression too. You cant expect more, really.

Your cam is like a 'stage 1' cam for a LS7. That with a stock LS3 intake wont rev high at all.


Depending on the dyno, I think you won't go anymore than 500.

Get real intake brother. LS3 is totally wrong, especially with the stock TB. ZL1 diff will rob 10rwhp+ I'd guess.


Torque numbers? that would be interesting to see. HP/mph graph sucks IMO.


The other graph makes sense, even compared to your, IMO. your engine is choked big time.

[kennyry83]

Ya I'm not looking for big power NA, just power left on the table before proceeding with the rest of the build.

I didn't think to get the torque numbers, was frustrated lol.

Ya I know a high ram and 102tb will give better numbers but going f1a its not really needed, just trying to square away with NA. The real big issue is not pulling passed 5900RPM. Both tuner as well as Texas speed stated that it should be 550+ wheel with the setup including the LS3 intake and pull well beyond 5900.

Just as an example, tuner I use has a 427 with same heads although bigger cam, and 11.5:1 ish compression on 87(e10) octane. He got 551 stock intake/tb and 587 with aftermarket (msd atomic) intake/tb - also stock mufflers. (see attached dyno graph)

If you ask why 87? "Just to see if it can be done".

[kennyry83]

Forgot attachment

[WHAMMO]

Originally Posted by kennyry83

Ya I'm not looking for big power NA, just power left on the table before proceeding with the rest of the build.

I didn't think to get the torque numbers, was frustrated lol.

Ya I know a high ram and 102tb will give better numbers but going f1a its not really needed, just trying to square away with NA. The real big issue is not pulling passed 5900RPM. Both tuner as well as Texas speed stated that it should be 550+ wheel with the setup including the LS3 intake and pull well beyond 5900.

Just as an example, tuner I use has a 427 with same heads although bigger cam, and 11.5:1 ish compression on 87(e10) octane. He got 551 stock intake/tb and 587 with aftermarket (msd atomic) intake/tb - also stock mufflers. (see attached dyno graph)

If you ask why 87? "Just to see if it can be done".

Maybe something else is wrong, but you cannot expect stellar results with what you have IMO.

Torque would tell a lot more ro the story.

The tuner might be good, but not having tq and rpm is a joke.

What car and CF for this other build? Too many factors can affect results.

Dyno numbers on my swtup can vary up to 40rwhp with just heatsoak...