Dyno results

[buguy]

So i already posted this elsewhere, but i wanted to see if anyone can help me understand it better. I really thought it would make power at higher rpms. Does it look right to you with that cam. Just wanting to figure out what's holding it back. I'm not disappointed, just surprised.
Here is what i have:
2054 (74x94)
Stock rods
Mahle "forged" pistons (not real forged)
AA 501 35x40 heads that i cleaned up myself with next to no knowledge
Dual springs and 1.25 rockers
Aluminum pushrods
Web 163 on a 112 lobe straight up (250@50 and .505" lift at my rocker) and helical gears
Efi
Water to air intercooler
E85
Single TB
1 3/8" home made header
Small turbo (should be good for 300 hp)

[Brian_e]

Those heads out of the box flow around 120cfm, and they choke hard at 4000rpm. If you blend the bowls, they will barely flow past 5000rpm, but still pretty low cfm. A decent 35x32 should flow 130+ @ .500”.

Did you have a real 3 angle valve job done? Did you remove the guides and do any port work? A fully ported set of 40x35 should flow 170+cfm @ .550 easy.

220hp is still no slouch.

Brian
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www.type-emotorsports.com

[buguy]

No i didn't remove the guides or have a valve job done. I just took that giant step out of it and cleaned them up. Tried to smooth out the transitions the best i could with the guides in. Blended the bowls the best i could without changing the shape.
I agree, I'm happy with 220. Actually made 241/263 with a couple more pounds of boost than the printout on an earlier run. Just didn't want to be running it to the ragged edge. Just trying to figure out what would be holding it back. Never even considered it could be the heads. I really figured it was the little exhaust, or maybe the cam.

[clonebug]

I doubt you have to worry about the header size.
I did a back pressure test on my header and it was only a differential of 5 lbs. at over 25 lbs of boost. You could have a 1.5:1 ratio and probably still be ok.
I would say it's a non issue. At least the gains would not justify the cost.

You can buy a cheap gauge, some brake line, a bung and then test it.

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[buguy]

I may do that Art. Since its running i want to add some more electronics. Speed sensor, maybe knock, temp before intercooler etc. Couldn't hurt to know the back pressure too.
Really I'm not digging for information for this engine. I have a new case, pistons and cylinders, crank, rods, and bearings waiting for a new big boy build. So I'm just trying to make sense of all of this before buying heads and cam.

[clonebug]

My feeling is anything else you do to make more power is going to be costly.

Along with the costs will be trade offs unless you build big to maintain the hp and torque down low.

Look at your graph......there isn't a N/A stroker that can come close to that power/torque output no matter how much money they spent. Along with that you are doing it before 5000 rpm and the stroker would need to rev to 7000 rpm.

You could probably gain some higher rpm hp with a long duration cam and expensive heads but your lower end drivability will suffer.
I would wager a bet it would cost another $2000-$3000 to gain that upper end hp.
If you do the math you are at 250-270 crank hp. That is at the limit of the 13T turbo and within 30-40 hp of the 19T.
Any quest for more power is going to require upgrading most everything you have.
Cam, heads and turbo will be a decent chunk of change and no guarantee you can utilize that output.

What it will do is lose your bottom end possibly to the point it will be more of and on/off type power........great for the track but not on the street.

Pick your poison.......
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[sled]

based on your description of what you've done to the heads, There is a LOT left on the table there. And in contradiction to what Art has said above, a proper set of hand built heads will not make your bottom end suffer. And when I say proper, I mean a set of heads with appropriate port volume, velocity, valve job, and chamber work.


A cam itself can not make an engine rev higher (breathe more) if the heads will not allow it to do its job.

I know you're not going to take that engine apart for changes, but I think the heads are probably the best place for improvement. Also the exhaust does strike me as a tad small, but maybe its fine?

this is probably for another thread...but what are your plans for a "big boy" engine?
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drive your split.

[buguy]

Sled i may go ahead and start a new thread for the big boy to start getting ideas. The engine i have now was mostly a compromise. I reused the cam i put in my 1600 shortly before building this one. Virgin case and Stock rods. Those heads i bought during black Friday for $400. Some cheap rockers from Dan. Paid $100 for those new/use pistons. Reused my entire efi/turbo set up from the 1600.
The new engine i had originally planned to make it a 78.4x94 9000 rpm turbo screamer. Now I'm thinking more along the lines of a 2276-2332 mid range engine. I was watching too many R34 GTR videos at the time and loved the sound of an engine singing at high rpms! The new engine will be all new and exactly what i want. Not that i need it or have the car to back it up, but i won't be happy with less than 450hp with the new one.

[buguy]

[clonebug]

[buguy]

Agreed! It's loud enough as is. I don't need any extra attention! The 2 step sounds violent! With the quick spool it really is awesome in traffic. And now i know i need to short shift it to stay in the meat of the torque so i won't be over revving it.

[Alstrup]

I have no idea about whether it is ok or good. too many unknown variables with the whp dyno´s.
That said.
The cam as such is not the issue to why the engine doesnt rev. It can be valve spring tension. (Lack of) But most likely its because the heads/intake doesnt flow that well. When the 1600 turbo drag class guys over here make crazy hp out of almost stock engines they use a lot of cam duration and a lot of boost and they don´t rev that high at the end of the day.

I have been on the side on a couple of turbo engine projects. One was a 2275 with 5,7" rods, Web 218 cam on 112 LC Gen 2 Wedge ports, 8-1 CR. blow through F.I. w.o. intercooler at the time. It pulled 290 hp and 380 Nm torque with only 13 psi boost. Later an intercooler was added and boost raised to 14,7 psi (1 bar) and power was over 330 at 6000.

Another one was a totally stock 1600 internally. Ported stock valved heads with a 4 degree taper in the squish area (Idea stolen from the V8 guys) 7,5-1 CR. 1,25 rockers.Custom intake system with 35 mm I.D., runners and a centermount 40 mm TB. Intercooler and a modified GT 2052 (I think) variable vane turbo 1½" TT turbo header. Wolf ECU with 60 KV Ford WS coil. At 1 bar it pulls 135 hp peaking at 4800 and 200 Nm torque.

So IMHO your next challenge is to make the intake system flow better.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[buguy]

Thanks. I personally wouldn't be able to do anything with the heads. I already did more than i have the knowledge to do. The intake is 50mm tb with 50mm intake to the plenums. The plenums are welded to cut down big beef manifolds that i match ported most of the way up from the heads to the plenums. I basically just guessed and made the head openings kind of like a panchito. In the pic that was before i smoothed it out. Guess i didn't get any pics of the finished product, but you will get the jist of it. Tried to take out as little as possible but still have smooth transitions. Blended the bowl best i could and tried to take anything sharp out of it. Porting is was above my pay grade!

[Bad bug]

[Alstrup]

[Wreck]

[madmike]

Hey Art,Mike isn't gonna lose bottom end with a stroker
up that cam & heads he'll be fine as wine
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'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[buguy]

Not on this engine mike. I'm building a brand new engine that will have the goodies in it. I already cringed on the dyno thinking about those stock rods and stock rod bolts that are in this one! I'm considering going back to the dyno to see if it will hold 30 psi. Man i don't want to be wrenching on it right now in this heat if it doesn't take it though!

[buguy]

So i was thinking about this dyno run and how i drive today. If i was going to be racing this, (which i probably wont) where would my best shift point be? Would i want to shift where it (or just past) makes peak hp, or where it makes peak tq?

[HotStreetVw]

It will vary by gear. The goal is to maximum the power under the curve. You can rough it by using the weddle gear ratio calculator to see rpm drops on gear change, or build something in excel.