Finally over 500hp at the crank but still has some problems.

[AMXSC]

Some of you guys know that I have been trying to build an engine to get over 500hp. Well after my 4th attempt I got success.

Here is the dyno chart.



But there is a few problems.

#1. I set the boost at 25psi but I get an overboost condition at around 3000rpm of about 28psi. I think it is happening because the turbocharger is building so much speed that it pumps more air then what the engine can use before the wastegate reacts to slow down the turbocharger. Is the wastegate preload too strong or is this normal? Should I worry about it? Any ideas?

#2. The wastegate bangs open at 3000rpm. It does not open slowly like I think it should as boost build. Is my homemade gills valve not working like it should? If I bypass the gills valve it does open slowly but the boost is only 15psi.

#3. I get boost creep above 6000rpm. Boost starts climbing again to around 28psi from 6000rpm to 6500rpm. I think the wastgate is too small? Should I even worry about it because I spend so little time above 6000rpm?

#4. Air temp after the intercooler climbs to 170-180 degrees. About 100 degrees over ambient. Before the intercooler the temps are at 260-290 degrees at full boost during a dyno run, but if I hold boost I see peaks before the intercooler of 320-340 degrees and a quick climb to over 200 degrees after the intercooler. Are the fans at the dyno too small to cool the intercooler or is the intercooler too small to cool the air?

#5. Hp is just flat after 4500rpm. Is the intake air temp too high causing the drop in Hp? Is this just all the air I can stuff though this motor? Is the cam too small to allow the engine to breath? I have seen hp increases above 4500rpm by adjusting the boost to 30psi but it kills the hp and torque below 4500.

Any thoughts or ideas please post.
James

[thebronze]

What wastegate are You using ??
What IC are You using??

BTW.. Congrats on the #'s

[merkurdriver]

What wastegate are You using ??
What IC are You using??

BTW.. Congrats on the #'s

( x 2 ) What WGA, what turbo?

Fantastic numbers!

[hEaT]

X3 on the WGA setup. With that much power, you should be running a good external. You should also be running a quality electronic boost controller (eBoost 2 is GREAT). That should solve items 1-3.

#4 - Probably dyno fans. Can you log IATs with a highway pull? How is air flow to the IC?

#5 - ECU could be pulling time due to IATs. What ECU/tuning are you using? Try playing with cam timing, but that will hurt you on the low end.

[whitelx]

Need a lot more info about the engine, turbo, and intercooler before we can answer your questions.

It would be interesting to see what happens with the boost once you get the engine into the car. The loading on the engine can change based on the gearing and vehicle weight and this can effect the way boost ramps up.

It's possible the turbine side could be too small and is choking the engine down at high rpm. The quick spooling indicates it could be a little on the small side. This may also be the cause of the over boosting issue, but that could also be due to the internal wastegate. I'm really surprised you haven't stepped up to an external at this power level.

What head and cam?

What kind of fans were being used on the dyno? How big is the intercooler?

The gillis style valves are designed to prevent the boost signal from reaching the wastegate until the set pressure is reached. This is why the wastegate doesn't open slowly. If you want it to open slower, you need to go to a programable curve electronic boost controller or a bleed style manual boost controller. Most low cost electronic boost controllers will have similar function to the gillis valve in order to provide fast spooling.

[LS2XR4]

at those power levels the gillis just wonT cut it. get a good electric one it will be money well spent.

[pyropete125]

pics of the header and WG would help too.

[AMXSC]

Question and Answers....

What wastegate are You using ??
What IC are You using??

The wastgate is an older bolt on Tial F38 with a blue preload spring. (Also known as a 1 bar spring)

The intercooler is a universal (china made) Turboworks 25x12x3.

( x 2 ) What WGA, what turbo?

The turbo is a Garrett GTX3576R with a .63 T3 exhaust housing.

Can you log IATs with a highway pull? How is air flow to the IC?

I can but it's not in a car yet. As far as air flow to the Intercooler on the dyno. It has a 36 inch diameter fan blowing at it. The fan moves a lot of air but to me it seems like it is just blowing around the Intercooler and is not very effective.

ECU could be pulling time due to IATs. What ECU/tuning are you using? Try playing with cam timing, but that will hurt you on the low end.

ECU is a PE with Maf conversion. Software is Binary Editor with Quarterhorse chip. Setup is 80mm Maf sensor 75mm throttle body and 65lbs injectors. The A/F mixture was adjusted mostly by adjusting the Maf table and the over rich open loop mid range was corrected with an adjustable fuel regulator. A/F ratio was adjusted as close to 12 as possible. The dyno oxygen sensor doesn't show it but on my Inovation meter the A/F ratio varies betweeen 12.5 and 11. Spark and timing are controlled by a standalone MegaJolt Lite (MAP version). This allows better independent control over timing and A/F mixture. The MegaJolt does not pull timing due to IATs it based on load vs rpms not like the factory computer. I may have the MegaJolt set to retard the timing a little too much so I'll check that. Thanks....

I did some adjusting of the cam timing but all it seems to do is shift the Hp peak and Torque peak up or down and does nothing to the upper end power it does however kill the power on the low end. I'm currently set 2 degrees advanced on the cam timing. It seems best at that point.

Need a lot more info about the engine, turbo, and intercooler before we can answer your questions.

What head and cam?

What kind of fans were being used on the dyno? How big is the intercooler?

More Information. The engine is a 2.5L. Lower end has eagle rods and wiseco pistons compression ratio is 8.7 to 1. Heads are ported iron N/A head. Valves are longer then stock but hand ground to fit each valve position in the head. The cam is from Esslinger but it is not their turbo cam it is the hydraulic 286/297 duration circle track cam. The head is modified for the oil feeds to the lifters.

The fan on the dyno is blowing into the intercooler is a 36inch round fan. It is blowing directly on the intercooler. The engine is cooled by a large radiator and fan mounted outside the building away from the dyno. The intercooler is a Turboworks 25x12x3 the core size I'm guessing is 20x12x3. It's probably the intercooler not being efficient enough it did however work ok when I first broke 400hp.

Also the wastegate is external. Between the exhaust manifold and the turbo is a 2 1/2 inch thick t3 to t3 adapter that has a mounting port for the wastegate. It's not the best setup but it is used for testing. It does however move the turbo away from the engine another 2 1/2 inches and should give me more room to fabricate a heat shield around the exhaust.

pics of the header and WG would help too.

I'm running a ported E6 not a header. I tried a few headers but I could not find anything that flowed more then a ported E6. Most that I tried did however flow better then stock manifold. The only one that have that was close was the ATR header but I only have one and it is installed on one of my SVO mustangs. Maybe this is the cause of why the engine doesn't produce any more hp after 4500rpm. Here is a link to the wastegate so you know what I'm using. http://www.tialsport.com/prod_wg_38.htm The wastegate I'm using is a little older. I bought it back in 2009.

James

[whitelx]

What size valves does the head have? What intake manifold do you have?

Did you base header/manifold selection solely on flow? I wouldn't necessarily change it out first, but if the other suggestions don't remedy the situation, it my be the culprit. I think your problem is the turbine housing. A .63 is too small for a 2.5L making 500+ hp. The intercooler is also too small and is most likely why you are seeing high IATs. A 36" fan should provide enough airflow. You could try constructing a shroud around the front of the intercooler to direct the air into it rather than it going around the sides. This is also something you'll want to do in the car.

[AMXSC]

What size valves does the head have? What intake manifold do you have?

The intake valves and valve seat started as 1.89 inch but I reduced the valve diameter slightly to 1.875. In addition a 30 degree back cut was also done to the valve head.

The exhaust valves are 1.59 inch. A back cut was also done on the exhaust valves at 35 degrees.

Both the intake and exhaust valves were then polished to a mirror finish before being installed into the engine.

The lengths of each valve was cut to to length to provide a .035 inch lash seting at each valve location.

Average port improvements.

Flow testing on a stock head with stock intake valves was 168 at 25in Hg. @ .5 lift.
Ported head with modified 1.875 inch intake valves was 248 at 25in Hg @ .5 lift.
48% improvement

Flow testing on a stock head with stock exhaust valves was 140 at 25in Hg @ .5 inch lift.
Ported head with back cut 1.59 inch valves was 178 at 25 Hg @ .5 inch lift.
27% improvement.

This is also the reason for the cam selection. The ports on the exhaust flowed less then the intake so the cam was selected with a longer duration on the exhaust to balance out the difference.

The intake manifold is the early style 1984 SVO Mustang upper and lower. The lower intake does have some material welded on it for ports 1 and 4 to allow some additional porting. The upper is ported and modified for the 75mm throttle body. This part was not selected for it's flow or performance. It was selected because I didn't have any other intakes available.

I think your problem is the turbine housing. A .63 is too small for a 2.5L making 500+ hp.

Im getting the same information and help from several locations I posted. The advantage of this turbo is the quicker spool, more boost at a lower rpm and better low end power. The disadvantage is that upper end power suffers because of it. Changing to a .84 or even a 1.06 housing will flow better and raise the rpm where it can reach peak power. This turbo can make 600hp if the engine can flow that much air and this also explains why I'm getting boost creep at the higher rpm range. The engine has run out of breathing room and this boost(backpressure) causes the wastegate to be fully open and when the exhaust flow though the wastegate maxes out. It forces more exhaust to flow though the turbocharger making the turbocharger spin faster and creates more boost.

What this means is the problem I'm having is too much turbocharger for too little of an engine. I think I'm going to need to do something better with the intake and the exhaust. I also need a better intercooler, a larger wastegate to control the boost and better boost controller. A different turbine housing and better flowing head. Did I miss anything?

The nice thing about this is that build #4 made over 500hp at the crank and build #5 will make more because of what I learned on it.

Thanks to everyone that helped.
James

[whitelx]

The intake definitely isn't helping up top either. The head may be flowing 248, but I imagine with that intake you're below 200cfm. This is the same issue I am struggling with right now (besides way too small of a cam). I'd suggest a .84 turbine housing and a better intake (fully port the lower and fabricate a plenum upper at minimum) to start with. Then move to the larger intercooler and finally the wastegate. With the larger turbine housing you may not need the larger wastegate.

The .84 will still give you relatively quick spooling and improved top end (3000rpm from the .63 is nuts, I don't get full boost till 4000, but it's an old tech to4e and journal bearing). More RPM will give you more peak HP, but the trade off will be slower spooling. However, you don't want to go so far you end up with a very small powerband and ridiculous HP (think big turbo supras). I think full boost by 3500rpm and pulling out to 7000 would make for one very fun and useful engine.


What is your plan for this engine? It seems like you have spent a ton of time on the engine dyno with several different combinations, but never put one in a car. I'm just curious. I'd love to be able to spend a ton of time on an engine dyno testing out different combos, but unfortunately I don't have that luxury. Impressive flow from that head BTW.

FWIW, Schneider spec'd out a cam for me with 230/220 @ .050, .475" lift, and 114 lobe center, 110 int & 118 exh. centerlines. This was to turn 7000rpm on a head that flows around 200i/160e. I haven't purchased the cam yet as I have a number of other issues to take care of first with the car and the engine. My current cam is 218/212 @ .050, .456/.450 lift, 106 intake centerline, 114 exhaust centerline, but it's done by 6200 even retarded 7 degrees.

[AMXSC]

Your right the intake is not helping, but I didn't have later style turbo lower intake. So I used what I had.

I'm just above 200 cfm on the intake so I give you a few more test readings I did for comparison.

Intakes

Ported upper 1984 SVO average port flow - 207 cfm 828cfm total
Ported lower 1984 SVO average port flow - 219 cfm 877cfm total
Early tall gutted turbo upper 926 cfm
Square pattern Turbo lower - Untested
Short stock upper - 696cfm
N/A lower - Untested

Throttle Body

Stock 45mm - Untested
50mm Ford 5.0L 523cfm
65mm Ford SVO 538cfm
70mm BBK 726cfm
75mm Accufab 916cfm

Exhaust manifolds/header

I am unable to locate my notes on this but the average port flow on a ported E6 is 218cfm and the ATR header is just a hair better at 220cfm. Compared to a stock e6 at around 200cfm. Bobs log manifold did very well although port 3 was a little low. It took about 5 minutes to fix with a little grinding. Bobs was 213cfm out of the box and 215cfm after fixing port 3. The china made header from E-bay was only little better then stock around 205cfm. I did not do any testing on Boport headers but Boport headers are around 238cfm according to the Turbo ford forums and I didn't test any center mount turbo headers. All the manifold/headers I tested flowed better then the iron heads so any manifold should work.

I'll try a .84 housing and see what it does.

What is your plan for this engine? It seems like you have spent a ton of time on the engine dyno with several different combinations, but never put one in a car. I'm just curious. I'd love to be able to spend a ton of time on an engine dyno testing out different combos, but unfortunately I don't have that luxury. Impressive flow from that head BTW.

I want to do a run at the Silver State 100. I did this once before with a 1989 Dodge Daytona Shelby turbo back in the early 90's and once with my 1985 1/2 Viper Red SVO Mustang. It should be fun to see what the XR4ti can do. Most of the time it will just eat up rice burners on the street and maybe some really quick trips across town for some ice cream at the local Dairy Queen.

Two of my engine combinations did make it into cars. My Viper Red SVO has build #2. Build #2 was a 2.5L with the t3/4 hybrid turbocharger 328rwhp. Build #3 made it into the White SVO. Build #3 is a 2.8L tall deck motorsport block with a GT35 turbrocharger 385rwhp and 442hp at the crank.

Before anyone asks what happened to build #1. Build #1 was installed into the metal scrap dumpster. It made too much hp for it's stock tiny rods and way too much boost on the standard turbo for the standard pistons. I'm sure it was making 800hp+ when the stock wastegate failed and boost climbed to over 50psi (just a guess because my boost gauge was not working). All I heard was ping ping Ping Ping!! Ping!!! PING!!! Bang!!!! Boom!!!!!!! ....... Sizzle..... Pisssssss....... Clunk Clunk Clunk...... BOOM!!!!!!

I get to spend a lot of time on the dyno and flowbench. I usually trade parts/labor and engines for engine dyno time. The flowbench I can use anytime I want. After I get it close on the engine dyno I chassis dyno it with the engine installed. The cost is around $400 for a 1/2 day. I just hate losing so much power with a bad tune.

The head took a long time to get it to flow that good. The head probably has a few extra miles on it from me carrying it from where I grind on it to the flowbench and back and forth. It took about 5 weeks to port the head working on it 1-2 hours a day. The hardest thing about it was the combustion chamber. Since I started with a N/A head the combustion chamber started at 54cc and I reworked it to 60cc, but getting each port and combustion chambers exactly the same took an incredible amount of time. I think the next time I do this I'm going to get a shiny new aluminum head just because it would be a lot lighter to carry around.

I don't have anything that compares to Schneider spec'd out cam in any of my notes. I do like cams with a larger lobe center and prefer ones in the 116-118 range. It should be a good cam compared to your current cam. I also like cams with a larger exhaust duration compared to the the intake duration, because the intake ports can be made to outflow the exhaust. Since you will be turning 7000rpm what are you looking at making for power?

James

[whitelx]

I'd really like to be over 350rwhp on 91 octane (I'll go e85 if i have to). I don't know if my little turbo will do it though. It's a T04e-46 wheel in a T04b compressor housing. The turbine wheels is a stage 3 in a .63 housing. It's internally gated and I just picked up a 3" outlet elbow to replace the restrictive stock outlet. I'd really like it to spool quicker since I'll be autocrossing the car. I want to be able to leave it in 2nd gear so I need a wide power band, but high rpm so I can reach 70mph. I also run a ported E6 manifold. The short block consists of arp hardware with crowed 5.5" sportsman rods and wiseco 8:1 pistons. The head is an early oval port with the large turbo-size chambers and 1.89/1.59 valves. I have a gutted upper and the lower has been welded up, but it needs a lot more port work.

The intercooler is a porsche 944 piece which is decent, but a bit on e small side. I am making the switch to a large NPR intercooler soon, although I have a big 3 core procharger and a smaller spearco intercooler that could be used if required.

Right now I am making 294rwhp with the tune set on kill. A little more street friendly, safer tune makes about 280rwhp.

[pyropete125]

Wow 248cfm @0.5" seems very high with an iron head... but you need that kind of flow for 500+

how is the wg oriented? no pics?

[AMXSC]

I'm sorry I don't have any pictures of the wastegate installed on the engine, but between the exhaust manifold and turbo is this adapter.



This is what the wastgate that is attached to it looks like.



I don't think I'll have pictures of this setup in the future because the adapter was used for only for testing and the wastegate is too small, and I'm also currently looking at changing to a cosworth housing and it looks like this.



If that doesn't work maybe a header with a wastgate port and a T3 .84 turbine housing, but I'm at my limit financially on the project so it will be stalled for a few weeks before the engine is back together. I'm also going to need to do something with the fuel delivery setup. Fuel pressure drops a little at the upper rpm range so I think it is very close to being maxed out.