Grim Reaper

Here is a dyno graph of the RWHP/RWTQ we were able to obtain with a ZZ4 engine with a Holley Stealth Ram running a 7730 SD setup.

The first run (S.001) was with a custom eprom the guy had done by a company that shall remain nameless for now (pending lawsuit) where the company refused after a few burns to do any more work and said "it's your engine/setup that's wrong...our eprom is perfect..live with it". This company was chosen AFTER the guy got another "expert" to help him and couldn't get the car to even run.

This was a "friend of a friend" that asked me to help out of desperation. Hearing the attitude of that company I decided to help. The graph alone shows the difference I was able to get in power...but the driveabilty was even more.

If you look at graph S.001, you will see the TQ/HP line was really eratic and has two "blips" between 3,700 - 5,000 rpm where the TQ/HP line mysteriously dropped. Excluding the "bump" at 5,000 rpm where the "max" of 218 RWHP shows, in reality it was only getting just over 175 RWHP and ran like crap (to quote the owner).

After a "test burn" (S.002) which does not show, I then did S.003 and S.004. You will note the far smoother RWTQ/RWHP lines (the engine now runs as smooth as glass) as well runs much better.

The differences between S.003 & S.004 is S.003 is setup with a lower spark curve so he can run 87 and S.004 is a hotter spark if he wants to run 91. Besides a little more TQ & HP, the engine also pulls another 400 rpm at the top end (for those wanting to know the differences between premium & regular WHEN YOU TUNE FOR IT).

What I found most interesting was the low rpm the Holley Stealth Ram produces max RWTQ. In fact, we don't know exactly where the max RWTQ occurs as it appears to be lower than the rpm range tested on the dyno (2,200 rpm S.003 & 2,300 rpm S.004).

But it does show the HSR & the ZZ4 would be a nice streat combo. Oh yeah, the tranny is 700R4 and the car is a 32 Ford coupe weighing only 2,200 lbs.

mrr23

here's mine. i have the zz4 cam but not the heads. also if you want, click the green banner and send me the info on the vehicle just like in the HSR CARS section and i'll add it to the page. send pic of car and engine bay also. 1987 ECM and PROM no tuning to it except on the MAF table 1 to get it to idle better.

grumpyvette

Glenn91L98GTA
looking at the dyno, it would appear that you need too degree in the cam you have to be re-indexted to a more retarded location by about 6 degrees ,OR a cam with slightly greater durration to reach peak tq/hp and move it higher in the rpm range

you might find this dyno graph of interest, as it shows the diffeance a slightly better designed cam can have,notice the EXTRA100 plus ft lbs of tq, this engines power falls off fast after about 3500 due to a restrictivre exhaust and restictive air intake, but you still see the potential the cam swap made

Grim Reaper

Grumpvette: Thanks for the suggestions, but it's not my car. It's a "friend of a friend" that had a hell of time with a "bunch of expert tuners" that didn't know how to properly tune an SD system (or too lazy). The real irony here, is the company that did the eprom for the baseline run (S.001) is the SAME COMPANY that put the engine & Stealth Ram combo together.

When my buddy told me the story, I felt so sorry I volunteered to help the guy.

MRR2: I will see what I can do. I've never seen or touched the car myself. I live about 250 miles away from where the owner/car lives. I had my friend do the Diacom & dyno readings, and then e-mail them to me, where I analyzed them and e-mailed a new bin for my buddy to reburn a new eprom for his buddy.

Right now, the car/owner is gone for a couple of weeks but I'll try and get a bunch of pictures of the car and the engine, and I'll e-mail them to you.

Ray87Z

Quite a gain, what exactly was this other company's problem that they couldn't get it running any better than that? Should not a stock 350 TPI tune have been better than whatever the heck they were doing???

Grim Reaper

Remember, this is an SD setup. VE, spark and PE tables are very important. You can be off a little and it will run fairly well - especially at part throttle where the O2 sensor will help in trimming fuel.

But these guys didn't have a clue when I looked at the VE tables and spark tables. Definitely not optimized for a StealthRam on a ZZ4. In all honesty, it looked very close to a stock SD bin.

A stock MAF bin would have probably worked quite well with just an injector chang had it been an MAF setup. A few tweaks and it would probably been bang on.

But it only took me a couple of shots to make it work with SD (SD isn't that hard once you know how it works). It makes no difference to me which is which - I'd recommend modifying the bin whether it was MAF or SD just to get every HP you can.

TRAXION

Which cam is that?

236° / 240° on a 110° w/ .555" / .559"?

Just curious.

Tim