secondarries

[Paul Workman]

My stock 90 LT5 WOT (w/ secondaries) torque vs. WOT after porting both runners and SPTs removed.

As Pete said before, I too can't see where torque was lost on the low end - at least not above 2000 rpm...



YMMV...

P.

[RHanselman]

Originally Posted by Paul Workman

My stock 90 LT5 WOT (w/ secondaries) torque vs. WOT after porting both runners and SPTs removed.

As Pete said before, I too can't see where torque was lost on the low end - at least not above 2000 rpm...



(Excel graph of data taken from separate dynos, SAE corrected.)

YMMV...

P.

Paul,

What we need is a comparison of the stock car with the GM ECM with and without the secondaries and then with the MS. If their tail is true then you'll see more TQ with the new ECM and the secondaries.

Cheers,
RH

[Paul Workman]

Originally Posted by RHanselman

Paul,

What we need is a comparison of the stock car with the GM ECM with and without the secondaries and then with the MS. If their tail is true then you'll see more TQ with the new ECM and the secondaries.

Cheers,
RH

Yep. Looking fwd to it. Hope took see the presentation @ BG!

[Pete]

Thanks for posting the graph Paul.

If you notice it has 25 more torque across the whole graph w/no secondaries.
You guys are saying from 1000 rpm it would spike up and at 2000rpm it smooths out.
So the graph would look like this.

[RHanselman]

Originally Posted by Pete

Thanks for posting the graph Paul.

If you notice it has 25 more torque across the whole graph w/no secondaries.
You guys are saying from 1000 rpm it would spike up and at 2000rpm it smooths out.
So the graph would look like this.

Nope, I'm not saying anything. Just passing along a data-point that the MS guys experienced during tuning my stock car. I'd like to find out if it's true.

Pete, I think you meant: "if you notice it has 25 more torque across the whole graph w/no secondaries AND PORTING"... By the graph it's unclear as to what mod caused the increase in TQ. Port could have made it all or they could have a ratio.

Paul, go out and put your secondaries back in real quick like and get us some numbers! In jest of course...

Cheers,
R

[Pete]

Ron,sometimes my brain is faster then my one finger typing.

I'm just speaking in general,not directly to you, just throwing out the way a stock LT5 chip programing works.

Paul don't worry you don't have to put your secondaries back in to find out.

From the old thinking bigger ports slow down velocity then Pauls ZR-1 and every other top end ported lt5 should loose more TQ/power.

Like i said in my previous post a pure stock Z secondaries are open anytime you go WOT no matter the RPM.

Stock LS3 has 260cc intake runner with no secondaries drives just fine,some CnC them to 275cc, stock LT5 head is a whole lot less from what i can remember 210-215 it shouldn't have any drivability issues we also have better valve angle.
Like i said i'm putting this stuff out from memory it's been a while since i did the R&D on the LT5 stuff (10 years).

The LT5 was ahead of it's time heck most LS stuff today came from LT5 development.
Pete

[Hib Halverson]

Originally Posted by Pete

(snip)
The LT5 was ahead of it's time heck most LS stuff today came from LT5 development.
Pete

Sheesh, Pete.
Where did you get the information that has you making that statement?
Or...maybe it's something in the water where you live?