Power falls off bad around 720 HP
 

So I have a fully built Evo that has a problem and I would like some input into the problem and see if we can squeeze more power out of her.

List of my mods:
2.3 Stroker 9:5 CR
Buschur Stage III head
3794HTA Twin scroll with a 1.00 housing
ETS 4" IC
3 LICP
3" UICP
Kelford 280 cams
Forge MBC
Tial BOV
AEM EMS
Boomba TB
Spark Tech
E85
Magnus V5 ( dual rail. FIC 1550 primaries and 1850 secondaries) Don't bother asking why I have this.

The power climbs all the way to 8000 rpm and boost holds at like 35 lbs but then falls flat on it's face.

We think that it's possible that the Kelford 280's are done and that's what is making it fall flat on it's face. The car does lag a bit but that is of no concern right now. We want to solve the power problems.

I do live in Colorado so the altitude should be considered as a factor.

Let me know everyone's thoughts.

Maybe bigger cams.

Any pics of the Dyno graph? What ecu are you running?

I would say cams for sure, strokers LOVE big cams. The other issue is the fact your running a storker so power WILL fall off unfortunately.

It's possible and we need to narorw things down more before I get my 4th pair of cams.

Sorry I am running AEM Version 1. I knew I was forgetitng something.

I will try and get a graph and load it up when I get home tonight.

time for bigger cams!

What wastegates and size are you running Josh? Which spring in each?

Have you checked for boost leaks above 30psi?

So what kind of Pump for fuel delivery? Nothing is mentioned.

Buschur DP with larger feed and return lines. I think they are -8 feed -10 return. (I think)

Shawn,

The wastegates are good to go. We went through them twice with the 4088 and made sure it was the correct springs and that nothing was being pinched (gasket).

Oh and I have an ETS 3.5 Exhaust so there is no restrictions there.

Damn Josh :( It's one thing after another with this car. Seems like the car should always make more power then it does.

Is this on Tobz Dyno? and 5000 ft?

I think the best guy to ask on a setup like this would be Aaron @ English Racing. He has had a very similar setup. Also post up a dyno graph.

LOL ya I know. It such a money pit. I was gonna email you as these are the cams I got from you. Hear of any defects with the early versions of the Kelfords?

Nope, but there are lots of things that can happen to a CAM depending on the install. They can flatten, etc. But we would really need to see a graph to see what's going on. Does boost just fall as well?

honestly man, i think its the twinscroll set up. all the cars with singlescroll kits made crazy power and held all the way. id be willing to bet that if you swapped to singlescroll it would solve your issue.

Josh,
How long have the valvesprings been in the car? Could they be losing spring rate overtime?

Are you running Kiggly's?

i was going to say, that turbine housing sounds kinda small. maybe the 1.15 would be a better choice.

Ever since I got the head. That's what we first thought maybe we are getting some kind of weird spring issue or maybe valve float. Maybe mike at AWD can chime in if he sees this and could answer it. I'm no mechanic.

It has the standard springs that come with the BR Stage III head. So whatever come with them is what I've had on there for a while. I got the head in Feb 2009.

What I can tell you is that my sweet driving skills has made the car rap put and bounce off the rev limiter a few times so maybe it damaged them then. Again this is due to my awesome (see crappy) driving skills.

Have you ever seen the 1.15>>> LOL it's huge and won't fit. I know because when I ordered the 3794 HTA I got it with the 1.15. Since my manifold was made to fit the 4088 from ETS there is no room for that housing. The 1.00 is big also and it took around a full day to get it to work as there were numerous problems due to fitment and how large it was.
I've been told (if you look here #23 https://www.evolutionm.net/forums/ev...o-sheet-2.html) that smaller one would be better.

I am hitting like 6000-62000 full boost so putting the 1.15 would move that to around 9000 rpms...

Josh, I hope you find the solution. I'd start with the larger housing.

Meanwhile, that's not a bad problem to have -- power falling off at 720 HP :)

Ya I know that's what everyone says. Thanks buddy.

Yeah Josh. Why can't you just be happy with 720whp. Really... :D

I was wondering why your car was there when we were tuning mine on E98.

whats the boost doing when the power is dropping?

If I recall boost stays around 35 and doesn't move. It stays on strong.

I had a similar problem with my 4088 and changed the housing to a larger one. Added more fuel. Did this, did that. Cost me a ton of money and ya know what it was..old turbo technology and I maxed the 4088 out at 674 HP. As soon as we bolted the 3794HTA on it shot straight up (HP wise that is) to where we are at now on the first pull.

I suppose it's cause I 'm retarded and want to reach the full potential of everything.

I'd throw a new set of Kiggly's at it for a cheap test.

After that I'd try a BW EFR 9180 :) with the big T4 TS hsg.

Sounds like a possible valve float issue to me.

Aaron

720whp corrected or uncorrected, Mustang or DJ, and you can see valve float in the dyno sheet in the event you cant hear it. I just recieved a 1.15 this morning and it doesnt look that big ;)

Aaron

I have a twin scroll kit and it holds to 9k and wants to keep going. Unfortunately i haven't had a chance to re-tune for more boost and higher rpm's. But i wouldn't say twin scroll kits don't make the power and hold all the way. I am in Colorado as well.

Aaron

I haven't heard Josh's car or seen the dyno sheet :) So there is hope :)

Not after what Geoff told me about the 9180. Lag doesn't bother me. It's fun as hell getting up to full boost on this turbo and the wait is killing me and I would need a new manifold anyways.

yeah you're right.

You need to:

A) move to washington
B) buy a 4202R
C) lower your hp standards.

Or get a bigger hotside? 1.00 housing should be enough.

When it falls on its face, is there a miss / hesitation / backfire?

That would be um uncorrected I think. It is on a Mustang.

Actually I was thinking of doing the BW S4000. It's the older style large turbo and it seemed to do pretty good on spool and made 684 on 24 lbs up here in CO on Tobz car. Turn the wick up a bit and it would be a sick setup. So I am tossing this idea around.

I do not believe so. I believe it is the same scenario when we had the 4088 issue. The car would perform great until the turbo couldn't compress anymore air. Honestly the last time I really hammered on it I loved it and feels so strong. But the dyno tells a different story. I just can't tell in the seat that the HP is falling off. Maybe because by that time I am doing well over 140 Mph and my attention is on the road more than the car itself.

I'd personally like to see the dyno graph and the tune in the car, particularly the timing map.

Depending on just how drastically it falls off I have a few guesses. If it's really bad, I'd go along with valve springs but don't agree with some of the suggestions for replacements. I don't think it's the cams. It could be the twin scroll housing too, I haven't seen one yet make great power up top if they have any low end at all.

720 should be corrected on his dyno.

Thats totally weird hp falls like that but it maintains boost at 35psi.

i disagree very much.

720, uncorrected on a mustang at elevation? doesnt sound too bad to me. :lol:

720 uncorrected on a Mustang is intense. I'll explain why. Marcus that owns the 2G DSM auto that has been on Tobz dyno showed his power with a 1.20 or 1.21 correction for sea level to make it right.

So if its a new style Mustang that reads like COBB (read DJ numbers) that would still be a bunch. If its corrected and reads like DBs then thats still not shabby. I am with Dave, we need to see the dyno sheet and timing map.

Aaron

That is corrected. All of Tobz numbers are corrected.

Mitch

Can you post the dyno sheet up today? I'd like to see it. I'd be glad to look at the map too if you want to e-mail it to me or just take a screen shot and send the timing map.

you can't argue with the graphs people have posted, the twinscroll just can't keep up at high rpm.

Josh - Hog out the current housing :)

http://img.photobucket.com/albums/v5...n/IMG_9343.jpg

http://img.photobucket.com/albums/v5...n/IMG_9342.jpg

1.15 a/r twin doesnt look too big to me. We compared it to Jeff's 1.44 which is definitely size huge (like 50% wider, has to have bolt reliefs).

Ya the problem with the 1.15 is that it's too close to the turbo housing and the bolts and such were too hard ot get in. I know it's crazy and doesn't seem right. But that's what we tried for hours on end.

I called FP and they said nobody has done the 3794HTA in TS configuration yet and I was the first and they really had no tech support for the issues. They also sent wrong fittings thinking they would fit. This was such a pain in the ass to get to work.

I will go with R/T Ernie. I had a similar issue with my car falling on it's face after 7000rpms. I'm not talking about the powerband nosing over, I'm talking about the curve falling off of a cliff. It was audible through the exhaust note on the dyno. After troubleshooting a few things I found it to be valve float. I switched to GSC Beehives (had BC springs) and this eliminated it.

I'm pretty sure Buschur heads come with Supertech Duals standard which should be plenty of spring, unless they are just worn out due to fatigue.

sounds like a valve float issue, have you tried to dyno on less boost to see if the power drops off yet. but if you want help from the pros you should really post a dyno graph it will keep everyone from guessing. and you will find your answer quick.

It defenatly not the cams ive seen kelford 272 make 814 awhp with supporting mods of course

I have used: Crowers, HKS, Manley, Kiggly's, Supertech, Ferrea and I am sure others I can't recall. Supertech duals have changed rates, unknown to use multiple times. It has, in the past, left me in some pretty piss poor situations. They offer MULTIPLE sets of dual springs, even today. With all that said, the customer service from them has been exceptional AND we currently use Supertech's.

Without a dyno chart/ignition map it's hard for me to actually help. Valve float is for sure an issue in EVO's and is fixed with a good quality spring. Since that is our head on the car and I believe it's been said it's from 2009, I'd say there is a good chance it's springs, I'd replace them with the new Supertech duals we are using, I believe their current spring is the BEST ON THE MARKET.

I have nothing else to give to this thread.

Thanks Dave.

English uses kiggly and they run 8s every weekend.

<- Has a set of Kiggly Springs in stock& located in Lakewood in case you forgot.

Shawn's Evo had the same problem before we installed our CNC head with Kiggly's & Kelford 280's.

{thumbup}

Thanks Lucas. I will talk to Tobz to see what he wants to do and I will keep you in mind and the offer you gave me. It would be nice to have them local for a quick turn around.

Here is a graph from Shawn's car last year. Only changes we made was our CNC head, kiggly springs, kiggly hla, +1mm ferrea valves, kelford cams, 3" upper I/C & ETS 4" core.

http://i55.photobucket.com/albums/g1...5/Headcomp.jpg

Hope this helps

Kiggly did a nice video of his valve springs in action. They are the best out there, IMHO.

Only changes? :lol: You added lots of power changing parts.

And to be honest as little as josh's car has spent actually running and driving the last few years I highly doubt his springs are already worn out. But if the supertech duels have been redesigned or changed in 2 years already maybe its the cheapest thing to try first.

True, I have not driven it much really. Maybe 3000 miles but I doubt that. But I have wrapped it out to the redline so that may damage them and if they are already bad then it would add to the damage that is already there.

Have you thought about rebuilding the motor completely? eliminate any worn out springs, check everything and rebuild the motor for your setup you have now. Wasn't that motor built like 5 years ago for a 35r setup? Try a simpler fuel system, single scroll 6766 should get you 800whp no problem.

Of course $$$ may be the issue.