50_Dave

Special thanks to Geoff from Next level for spending extra time to help diagnose problems. He did the tuning. The guys is just so damn nice to people.

Engine is a 402 with afr 205 heads hogged out.

Sts twin turbo kit upgraded with bigger turbos and ball bearing cartridges.

We ran into some problems, though. The turbos were taking a while to spool up. The eboost2 solenoid controlling boost kept getting stuck open.



When we hit 5k rpm the boost would spike to 18 psi and we had to let off. So for right now, it is at 654/699 at 4800 rpm.

The car at 18 psi when the spike hit made 790 and 770 with 13 degrees of timing at 5800 rpm. Wish i could have reved that one out to 6900

Once i get the boost issues sorted out, ill go back. For now, I have a 4700 rpm rev limiter lol. My goal is for 800 rwhp at 14 psi at 6900 rpm. We will see.

As for other sts kit owners. What are you guys doing to help spool the turbos quicker. What size wheel/exhaust housing are you running, and what kind of exhaust set up? I have the lg pro longtubes/exhaust system running into these turbos. Any help with wrapping anything?

Mike 01WS6

I'd switch back to the stock cast iron manifolds. Thats what basically every STS owner has done and it's proven to spool the turbos faster. Also, wrap the exhaust all the way back to the turbo. You can also drop your exhaust size down to 2.75" instead of 3" all the way back.

ddnspider

iTrader: (26)

looks like a centri blower dyno

Qwick98Z

It had a 10 percent load on it.

70Stang

iTrader: (2)

Dave, get those longtubes off the car! The STS really likes stock manifolds. Coat them and then wrap the rest of the system... on 18lbs you should be making a ton of power.

50_Dave

Well,

I think we figured out a big part of the spool up issue today. While on the road, we saw 13.3 psi at just before 4k rpm instead of the 6 we were seing on the dyno. It seems that we need more load on the car. Seven more psi is huge earlier on in the torque/hp department.

I think with more load, that graph gets shifted to the left more, and even more power gets made. I may not need to ditch the long tubes just yet!

Btw, you should run 2 solenoids with the eboost 2 when told to so that you dont end up with a stuck one like mine

98Z28MASS

iTrader: (6)

AS others have said get some good short headers coated/wrapped or sme stock z06 manifolds coated/wrapped and you should see some quicker spool time. Also, check out the thread by Zombie as he lists out all the essentials of what you need to do to get an sts kit working properly.

Kelly.

if you wrap your exhaust, wrap it from the back forward so the wind doesnt get under the wrap as you drive

what size twins?

50_Dave

I have some already. I just need a catless mid section.

I have also seen several cars make over 800 rwhp and one make over 900 rwhp with the longtubes.

There was a difference of nearly 8 pounds of boost between the dyno and the street. I will try the load first, and then go from there. But i can gaurnatee you that graph will be shifted well left and the power will be up a whole lot more if we can get the turbos to spool on the dyno as they do on the street.

W8N2SQZ

iTrader: (6)

What turbos are on the car?

Glenn

bboyferal

iTrader: (9)

Sure, with a lackluster curve.

Louis

iTrader: (7)

Dave, stock manifolds There is too much energy being lost to spool them.

70Stang

iTrader: (2)

To give you an example...we made 640 on 9psi with a custom single rear mount on a stock motor.

Do the stockers...please!!

RooRnZ28

iTrader: (14)

the LT's are hurting you more than you think...... i currently have LT's, and although the spool for me is still fairly quick, they leak like a bitch. My heads are black from all the exhaust leaks because of the LT's, something that i didn't even realize until recently

Qwick98Z

The exhaust is leak free, It was checked on the dyno. I guess we will see what happens, We will try it with the LT's first and if it will not make the power we want we will make some changes and see what happens.


If it makes more power on the stock stuff, I will have to tell Paul Major he's doing it wrong

bboyferal

iTrader: (9)

Apples to (Insert other fruit here).

50_Dave

Thansk for the help everybody. I appreciate the feedback/tips.

However,

I had asked for some tips from people who have done the set up. I had an issue of only seing 6 psi of boost at 4k rpm, and wanted to know about certain ways to overcome that. Some said longtubes issues, some said wastegate issues, etc.

I have found that if I put the car on the street, i am making 14 psi before 4k rpm instead of the 6 psi I saw on the dyno. My original question/problem, "how do I make these spool faster?" Answer, more load on the dyno. Not stock manifolds. The problem is that I did not phrase the question properly, as I did not know how the car would react on the street, only the dyno. Not fair for many of you who only saw the graph, and not the street results.

70stang, congrats on making 650 at redline with your sts car. Thats pretty good for a stock car. I made that at 4700 rpm with only 11 degrees of timing. Had i been able to carry out the 13 psi to 6900 without the boost spike (btw you also told me i could run 1 solenoid with the eboost2 and that failed), the numbers would have been huge.

The, "horse to water," and "i told you so" approach is not exactly kosher in my book. I think 14 psi before 4k rpm negates this approach. I will have the car on the dyno with proper load, and I can assure you, the curve will look much different now that I have figured the issue out. A 7-8 psi swing in boost underneath can really beef up the graph.

Thanks for the tips, i appreciate it. I really did weigh everything out, but stock manifolds were not an issue.

Qwick98Z

If you really think about it, Paul has to spool twin 47-88's with Im guessing,
.96 exhaust side's with only 427 cubic inches. David is spooling twin 60-1's with .48 exhaust sides with 402 cubic inches. So I think we are in the same ball park, Keep in mind that the pulls are only to 4500 rpm we still have until 7200 to see what power its going to make.

I think it just needs more time on the dyno, I understand that the stock stuff will help spool time, but will it hurt the top-end power?

2001WS6Vert

I would think that the higher flowing the build is that the need for stock manifolds diminishes. The mass and velocity of exhaust sent out would effectively take out the need for wrap and stock manifolds to retain heat. I could maybe even see it possibly as an advantage over even a front mount turbo for overall power in a very high HP setup, ie Major's car. So much air is flowing so fast it negates any disadvantage long piping might be to a lower power build. Just thinking out loud, never messed with a rear mount, don't hurt me.

Qwick98Z

And you may be right; I guess the best way to find out is with some testing. On the other hand on the street the car made the same boost 1000 rpms before it did on the dyno Do you thing that load helps the rear mounted turbos spool better?