I want to put a disclaimer at the beginning of this thread, so that people don't take things out of context, I almost didn't post the info because I want people to look beyond the peak numbers, and so many just drop numbers that I didn't think it would be the right time, but Im pretty well certain I have things figured out, and this will be an ongoing thread to show improvements. Please read all the info before jumping to conclusions.

The Truck is Keith Olin's truck, its a 1986 supercab F250, ZF5, the engine setup is as follows:


94 IDIT rebuilt 20K
Stock compression
R&D Girdle Kit
R&D Stage 1 cam
Head Studs@150ft/lbs
RD2-90
R&D Prototype Stage 1 injectors
R&D Stage 3 Turbo Kit
HX35 12cm housing


The First Dyno day was about a week and a half ago. It had B code injectors with an early RD2-90. (My 18m old Daughter decided it was an awesome piece of paper to color on, sorry for the random colors)





I was really disappointed with this graph, it was as much as I could get out of the truck with tuning,The truck felt so much stronger than this. After I dwelled a bit on it, I did see a silver lining. Peak Tq was at 2000rpm (Right where I felt it was going to be) and peak HP was at 2600 (Flat to 2800). This was telling me that the cam was doing right what it was supposed to, broaden the power between torque and horsepower peaks, more area under the curve essentially, better drivability as I have felt shows here. Other than that, I had to figure out why the peak numbers were so low. It cleaned up the fuel real early, even Eric (Owner at Eric's Automotive, who has a 700hp Turbo trailblazer) commented that the turbo was burning all the fuel way to early. This was pretty much solidified with the numbers hitting a brick wall no matter what I did.


Onto the next chapter...


So I was embarrassed with the peak performance on the dyno, especially with stock 6.9's w/ ATS kits outdoing those numbers, not to mention my pump and sticks were leaving a customer hanging, that I gave him my own personal RD2-90 to swap with his, and beforehand, I even had it benched... 90cc's from 1000-2800, dropping to 75cc at 3300rpm. This is still actually less than the current RD2-90's output (100cc peak to 90 at 2800 and 75 at 3300), And I also wanted to test out a new set of Stage 1 injectors. After he installed the pump and sticks, he was seeing 25psi with the WG unhooked... Fueling was a lot better.


So fast forward a week...


We get on the dyno again today, and again, we were having trouble pulling the HP numbers up, still hovering around 200whp. checked his timing, and it was at 14* BTDC ..... So we backed it back down to 10*... Run it again, whp was still just over 200, but the torque shot up BIGTIME.... 483wtq at 2000 RPM, with 470ft/lbs from 1800 on... Backed the Timing down to 5* BTDC, and lost 20wtq (463), whp dropped to 193... Bumped timing to 8*, and torque came up to 474ft/lbs, whp right at 200 again...


The sweet spot of the day was right in about 10* BTDC...





Eric and I were analyzing the dyno charts to figure out what was going on, and with his experience in turbo powered vehicles, along with what we've seen on this dyno on multiple trucks, we concluded that the 12cm HX35 exhaust housing is just too damn small for the IDI, we were spinning the exhaust wheel too hard and it wasn't efficiently delivering the air charge, it was also the reason Keith was seeing 25psi with the WG unhooked (Which Ironically delivered WAY less power on the dyno even with 21psi vs. 17psi, the wheel was moving too fast for the flow of the engine). We were also seeing 2:1 drive pressure to boost pressure ratios after we found the sweet spot.


So the conclusion....


Below is a chart of my truck and Typ4's truck laid over each other on the same day, almost 3 years ago, on the same dyno. You can see the contrast of the Typ4 cam and the J2 cam, with proper airflow in each truck, as well as enough fuel to drive each setup. Below that is my explanation chart of todays dyno with Keith's truck, which to date, is the torquiest mildly fueled truck, and feels that way, leaving us all baffled by the numbers it put down.






Anyway, Keith already has a 62mm/86mm compressor wheel for the HX35 ready to go, and we are going to try and find a 14cm or 16cm exhaust housing to drop in on this to get some more flow out of the turbo. I also have my 190cc DB4 being prepped and verified for numbers as we speak, and it will be swapped in place of the 90 next dyno day for direct comparison numbers, and hopefully breaking the 400whp barrier.... All on a stock compression 7.3....


More soon...

 

Subscribed. I mean freakin subscribed!!!

 

If it was easy to figure out, you wouldn't be the one trying to figure these things out.

 

Looking like might be just dropping a 366 on it at this point.


Pretty much got the info we were looking for as to how an HX35 performed on an IDI, and it would be counter-productive to throw a bunch of upgrades at an HX35 for it to be too small for the 190. Might just run a 366 with the 90 and then drop the 190 on after we get numbers out of the 90. Its up to Keith, its his truck, so we will see what he decides

 

Get it man

 

This is some very nice information... thanks for sharing. The text overlay on the graph is not really legible, but I get the gist. I am really interested to see the follow up on this with different turbo and/or fuel combinations. What is the status of your turbo kit production?

 

Im looking at doing a couple/few kits up here next week. I have a customer who wants one, and Ill probably make 3 while Im doing them up.


If you click on the photos, it will take you to photobucket, and there is a button to zoom just of to the right that will make it larger, that way you can read whats going on clearly.

 

I think racer30 (my brother) has an 18 on his hx40 gets ya thinkin, need more turbo ****...

 

Yeah that HX40 has a bigger exhaust wheel as well, so a much better flowing turbo overall.


I think I could bandaid things and get a little more out of it if I modded the WG actuator to loosen it up a bit, it would definitely slow the wheel down some more and unchoke the hot side better, but I have a feeling it would kill boost resulting in similar numbers... A stock 8-blade HX35 is just too small for a 7.3. I know that Hyde over on OB is running an HY35 (Smaller hot wheel AND housing) with a 35mm external gate and he dyno'd 219 without water/meth, but I think effective gating and the 7 blade (higher flowing) 35 wheel was how he extended his hp range a bit.


I will say this, I drove Keith's truck after the dyno, and you wouldn't believe it was only putting down 204whp, not everybody drives around at 2800 RPM, so that's the main reason why, but you really can feel the low end of this engine. I don't think there is a DB pumped truck out there putting 204hp to the ground at 2300rpm, that's where most peak out at at 2800. I think we are going to see some good gains by swapping out the turbo, 240hp/480tq range with this pump. Then Im hoping for numbers in the 450/900 range with the RD4, and as long as we don't run into a wall with something like this again, or the engine says no and scatters, I think think it would be a good estimate.

 

Subscribing!

 

Ok...


Got back on the dyno yesterday...


Swapped on the Stage 3 turbo, no changes, other than timing to 6*BTDC...


Ripped a 243/528 the first run.... Even better than I expected..


Then we swapped on the 190, and gave it about 20 runs.... Started having some little issues with valve train (Maybe pumped lifters??) and his lift pump relay was cutting out...


Still got to 350whp/778wtq... Which beats my trucks numbers...


The best part was with the 90cc pump, the truck was putting down over 500wtq with a constant load at 1700RPM.... With the 190, it was doing over 700wtq at a little over 1600RPM!.... Trailer towing torque right there...


I put a Youtube vid together, please ignore the advertising, I didn't wanna make a second vid just for the forums, so if a Mod feels like he needs to remove it, so be it...




We will get on the dyno again soon... This time the pump will have dynamic timing and hopefully push things over 400...

 

That is indeed the "best part" in terms of how the truck drives and pulls... so did you get a chance to drive it around with each set up or was the switch for the dyno only? Those are some very strong torque numbers, good job!

 

Wow....

I usually look at amped-up newer diesels in magazines like Diesel Power and Diesel World.... and often as horsepower goes up, torque doesn't necessarily increase the same amount. Here we have a way-turned up IDI that is making over twice the torque as horsepower!!! Very impressed.

Good job man!

 

trailer towing torque sure but your going to get pulled over for obstructing the view of the entire road lol! not exactly practical pushing that much fuel through her.you'd need to measure your mpg in gpm. i dunno if you could stuff a large enough intercooler in her to actually be able to pull max gross up a steep grade at that level could ya? (if you could find a stretch with no one around.don't let the emission ***** see ya.they'll hang us all lol.)







but that's a lot of fun to watch.

 

I think you could clean that black smoke up with more timing and turbo tuning.