3.5L Dyno chart
 

Got over to a local shop and had my 3.5L '86 run a few times before the chip gets tweaked.
http://forums.pelicanparts.com/uploa...1315497211.jpg

Wong got pretty darn close right outta the shoot (no surprise). Looks like it's making what it's supposed to.

Thanks to Steve Weiner and Steve Wong for their wisdom and help. Top shelf!

Those are wheel numbers, BTW.

Well done, Sir. My compliments to the Chef.

You did that engine and thats something to be damned proud of! :) :)

I wheely like them!

Nice hp and torque curve. I've followed you signal splitter troubleshooting as I was installing same box then. It's pretty easy solution to twin plug 3.2. I'm running Mr Wong first iteration software too, but no dyno results yet. May we know you engine specs in details?

Great numbers! I am planning a twin plug 3.4SS build and would also love to hear your build sheet.

Build sheet as follows...

100mm JE slugs (10.5:1 CR, but not verified), case mods by Rennsport (thanks Steve!)
Pauter rods
Heads by Rennsport (thanks Steve!)
EH intake runners (rest of the intake is stock)
New Sachs power clutch
Completely rebuilt tranny (one piece Wevo carrier plate)
964/993 dizzy
Andial splitter
1 5/8" headers w/hand made dual out exhaust and magnaflow muffler (local welder)
Wevo engine/tranny mounts
new Bilstein rear shocks and aftermarket sway bar.

I don't want to say it was a simple build, but it went off without a hitch. No leaks! Not one...nada.

Pulls good from 3500 to 6K. But I'm itching to take the next step and do ITBs. That little intake door is now the limitation to more suck that would give it that little extra Wow factor. Maybe I'll do it on the next car. Don't know yet. It's getting cold here, so maybe I'll upgrade brakes and suspension next. Brakes are fine, but the "dip in" when letting off the juice going into a corner is a little strange and leads me to believe that the front struts need to be upgraded.

Sounds great. Growls like a proper angry F6. No regrets. If you're doing a similar build, you'll enjoy the results in a light car like this. V8 peeps give it respect now.

What Cams?

Nice build, similar figures to my 3.4 (273bhp / 240 ftlbs) - thinking there may be something left on the table for you?

964 cams

Yes, it appears that there is a little left on the table somewhere. Might have it dyno'd again after Wong gets me the new chip.

It's been 3 years since I built this and it's running great!

It might be time to see if I can screw things....I mean make things better.

Contemplating taking the next step and putting ITB's on this build. Besides the cash outlay (yikes), the only thing stopping me is finding local support for programming an ECU. Anyone know someone in the MN (USA) area that they trust/have experience with?

Steve (Rennsport),

I'd love to hear your thoughts (and products) along the ITB lines that would get me to successfully making a 300+HP snorter.

Sorting EFI for a race motor doesn't need to be all that complicated as long as the system you purchase doesn't depend on reprogramming stock chips, but is software programmable so you do the programming on your laptop at the dyno. As an example, look at Electromotive. You can download their manuals.

You don't really need to optimize each cell in the ignition or the fuel injection matrices. These typically have manifold (absolute) pressure on the vertical axis, and rpm on the horizontal, with timing advance or injector on time in the individual cells. You can get the HP/Torque you need by inserting the same values in each column, so that RPM is the only variable.

This works because you only really care about WOT values. If part throttle values are less than they could be, it doesn't matter. If you are feathering the throttle around a corner, your right foot adjusts the power you can stand at that rpm/speed.

Someone would probably give you some decent values for starting up. On the chassis dyno, you can look at what the AF ratios are and do more tweaking where they look off, and play a bit with ignition timing.

Which isn't to say that a professional tuner couldn't do perhaps a bit better in a shorter time on the chassis dyno. Somebody in Minnesota is going to have a chassis dyno. There is at least one experienced race shop out by White Bear you could talk to. Chicago and Milwaukee aren't all that far away either.

Guys doing this for street engines do want to get each cell right, because that improves their miles per gallon. They can drive around at various throttle positions/speeds and have a passenger adjust things. That isn't going to help you at WOT in a race car.

300 engine HP ought not to be that hard to achieve in a 3.5 liter motor. The factory race motors were usually shown as 110 HP/liter, so a 2.8 RSR motor delivered 308 DIN hp.

But I think you are right in worrying about the 915 and how far you want to go with the power.

You have several options and some work much better than others. :)

1) ITB with resonant plenum

2) ITB stacks such as PMO's.

#1 makes far more torque everywhere in the RPM range, however this system costs more.

#2 Make the same HP, but less torque below peak HP, however this is the lowest cost option.

Engine Management is critical to the overall success and there are many options (and opinions) about which one is the best choice. We use Motec M84 for everything we do, if that helps. Be prepared to spend money & time here to get everything programmed and tuned so it runs correctly under all conditions.

Choose an ECU that your nearest tuner is familiar with. Unless you can tune it yourself, then choose that feature/cost ratio is best for you.

Option #1... what's the typical cost on a system like that?

I've got a 3.2L in my 70' T IROC and I'm looking to upgrade the motor down the road and need to know what I should plan for. Thinking of bumping it up to a 3.4L, aggressive cams, 10.5 or 11.5:1 pistons, twin plugged, and a few other giblets as needed.

You will spend around $6500 for the complete intake system sans Engine Management & harness.

~$11k including motec M84, harness, injectors etc :D

Welcome to Rothsport Racing - Engine Products


nice, very nice http://forums.pelicanparts.com/support/smileys/pray.gif

Thanks for the guidance all. I work in automation and am very experienced when it comes to programming things that take "tweaking". Thanks Steve for the suggestions of systems.

I come from the school of "do it once and do it right". A little more money and time are worth it in the end when get that feeling in your rear end of being strapped into a properly built, light weight, ride. The government can't tax fun....yet.

The 915 is a back of the mind concern always.

Have to mull all this over a bit more in my little engineering mush. It's so nice now, but I need just a little more. It's a true addiction.