Engine and EFI project almost complete

[David]

I guess I haven't posted the full details of my never ending project on the new 930 forum. I was going to wait until it's finished, but I was at the tuner's yesterday and I just had to share.

Engine details:

3.4 JE pistons w/7.7:1 comp
Mahle fully finned cylinders
Pauter rods
Twin plug
Heads matched to Carrera intake
EBS perf valve job & springs
964 cams
B&B header & custom muffler
K27HF2
Motec M600 ECU
Wasted spark ingition M&W Pro-14 CDI and 6- dual coils
Patrick flywheel
Custom intercooler from 25 x 10 x 4.5 Bell core
Tial 46mm wastegate & blow off valve



The tuner got most of the fuel mapping done and some of the ignition mapping. Before we called it a day he made a couple of full dyno pulls. The boost was set a 0.7 bar, the intercooler was hot, and it made 390 rwhp. I'm hoping for 500rwhp at 1 bar, but I don't know if we'll get there with some more tuning and a cool intercooler. The power and torque curves are very smooth, I'll try to get a copy of them next time I'm over there.

[slow&rusty]

David what AFR did you peak at?

As an aside, (and unless you were super rich - which I am doubting) with the extra 0.3 bar (4.4psi) of boost do you think that will really yield an extra 110whp? That is very significant. My initial thoughts and from my time on the dyno, are that it more than likely yield half that - realistically. Interested in hearing your thoughts.

Next time you dyno your engine please install it in the car, you might burn those plastic wheels off your cart!!

Yasin

[RarlyL8]

Wow - I'll bet you can't beleive it actually runs after all this time.
I've followed the engine build over in that forum for quite some time. Nice documentation.

I enjoy we have a place for turbos here at Pelican. I know many folks, myself incuded, that hesitate or simply do not post over at Rennlist due to the hostility and arrogance.

By the Way David, I still have plans to use those flanges you made for me. Many many things going on .....

How did you come to the 500RWHP figure? What elements of the build will allow that? 400RWHP is a nice number with a hot intercooler. Hit it with a cold shot of nitrogen or some other compressed gas and see what happens. Is the tuning complete or do you expect big numbers from optimizing spark and fuel?

[Jim2]

Wow David, it looks good and performs well. Stock output being around 300 HP, you have made about a 33% power increase on the same level of boost! UNCORKED!

I have yet to dyno mine, and I'm still on small injectors too. I'll be curious what your outcome is with the extra boost and a cooler charge.

The SDS guys did a couple simple calculations for me which accounted going from .7 bar to 1.0 bar, as well as reduced inlet charge temp from 195 F (no intercooler) down to 100 F after intercooler install. Based on the current injector duty cycle, injector flow rate, and AFR they can reverse calculate CFM consumption which relates to power. My current calculated output was 390, and the forecast was 511. This first digit sold me on buying dyno time in the spring.

Be sure to post some updates. Any pics of your finished intall with the intercooler etc?

Jim

[DDDD]

I think your car will be plenty fast with mid 400's at the rear wheel!

I called Prototech, and to make 490-500 rear wheel horsepower, they take your cylinder heads out to 41mm with a special liner. It takes a lot to make that much power, in other words, and if your build is reliably in the 400's to the rear wheels, I think you'll be happy. I'd love it!

[David]

I was trying to keep up with the tuner (Sam Shalala at ProTechnik) as he was adjusting the fuel but even after taking the EFI101 course and with my engineering background I could tell there's way more to it than taking a class or reading a book. I think using a good tuner is worth more than money spent anywhere else.

I'm not too optimistic about acheiving 500hp, but it's there Sam will find it. The AFR's are still a bit rich in the mid range so there's still some work to do there. There's also a lot more work to do on the timing. Most of the time so far was spent on bottom end work. He got rid of most of the dead spots, but said we need to do some tuning while driving to make sure they're all gone. I think he wants to do that before he does the top end work. I was just happy to hear it run, more like hear it wail. The scream was fantastic if not painful.

[dean]

Hey David,

Congrats on your car. What dyno does Sam use. I like Sam, he machined my G50 bellhousing and did a great job. He also talked my ear off.

I hear you about dynoing a motor. I had mine on the dyno for 4 hrs and the amount of info flying at me was mind blowing. I couldn't keep up. Plus the shreak was intense. All the guys in the shop (big shop) were pissed at the shreak by the end of the session.

Enjoy your car
Dean

[oms930]

Fantastic looking engine David (an inspiration for trying to do the same) and I am sure the long wait will have been worth it once you get the car back. I'm sure the HP number will be high enough.

What kind of injectors do you have? How much do they flow?

[hobieboy]

Very nice David... Please do keep us posted about your progress to the final finish - I'm sure you'll find more hp and drivability once its properly tuned.

I'm in similar boat so yeah - dyno time is really tempting in the spring

[David]

Originally posted by dean
What dyno does Sam use.

Sam's got a Dynojet dyno. I know all the issues people have with them, but Sam knows what he's doing so I'm not worried about the dyno.

[David]

Originally posted by oms930
What kind of injectors do you have? How much do they flow?

They're Mototron (Siemens) high impedance injectors. They were listed as 65lb, but I'm only running at 38psi right now so I'm a bit under that.

[Rob 930]

David,

I'm glad to hear that it's running and getting tuned. I think you'll see some big increases as you bring the boost up. I saw a 100 ft-lb increase in torque from 0.9 to 1.2 bar. I realize you may not go that high with boost, but the relative change may be similar. Any reason not to tune it for slightly higher boost? It sounds like you've built it to handle at least 1.2 bar. You might want to go with race fuel, though, if you go above 1 bar. In fact, you might want to have a map for race fuel anyway which will allow you to optimize the timing for more power.

I'll be interested in your duty cycle with those injectors. I have the same injectors, but I think I had my fuel pressure closer to 44 psi. At the higher boost levels, I'm getting over 85% duty cycle. My tuner was not concerned about it, but it has me wondering. To improve it, I may have to increase the fuel pressure (or change to larger injectors, which I'd rather not do at this point). If you find yourself edging up on duty cycle, it would probably be good to raise the fuel pressure now so you don't have to re-tune later.

Rob

[David]

That's encouraging Rob, thanks.

The Motec M600 allows for different ECU maps. I've got a 4 position dash switch for it, but I haven't connected it yet. I am planning to have maps for different fuels, maybe even E85 if I get bigger injectors. Don't worry, I'll keep an eye on the injector duty cycle.

[David]

Originally posted by Rob 930
I'll be interested in your duty cycle with those injectors. I have the same injectors, but I think I had my fuel pressure closer to 44 psi. At the higher boost levels, I'm getting over 85% duty cycle. My tuner was not concerned about it, but it has me wondering. To improve it, I may have to increase the fuel pressure (or change to larger injectors, which I'd rather not do at this point). If you find yourself edging up on duty cycle, it would probably be good to raise the fuel pressure now so you don't have to re-tune later.

Rob

I found the spec for my injector at http://www.whipplesuperchargers.com/pdf/65longinj.pdf

It lists static flow to be 10.8gm/sec at 600kPa.

I convert that to be 85.5 lbs/hr at 72.3psi gauge pressure so it sounds like they'll flow plenty of fuel if your fuel pump can make the pressure.

[David]

The engine tuning is just about finished. The final run, still at 0.7 bar, it made 416 rwhp and 357 ft-lbs torque. I think it has a good chance to make 500 rwhp at 1 bar. I'm going to take it home tomorrow and get some miles on it before turning the boost to 1 bar and putting it back on the dyno.

[David]

Here's the dyno sheet from the last couple of runs. Unfortunately I spilled a little water on the print out

[Craig 930 RS]

I predict 461 RWHP at 1.0 bar - nice build!

[Rob 930]

David,

I'm glad you got it together. Are you sure those weren't tears of joy, or maybe a spattering of champagne that stained you dyno sheet?

How does it drive? What's next, more boost?

Rob

[Texas Turbo]

Very nice, congrats David! Enjoy it in good health.

-TT

[JimCulp]

I can't imagine how nice it must be to have a running car. Congrats- those numbers look good. How are your AFR's at the higher revs?