-
Caddy 1.6TD dyno run
by
veeman
on 30 Oct, 2006 06:21
-
Just thought I'd post some dyno results from this weekend. I wanted to do a baseline run before putting on the intercooler system and a local shop let me squeeze in a few pulls on their DynoCom dyno this Saturday. Since I don't have a tach yet, the shop set up a really slick photo-electric pickup on the crank pulley. Very cool.
Here's what I have now:
-1981 VW rabbit truck with 1.6TD engine (recent rebuilt mechanical head)
-Stock A1 TD airbox
-Stock exhaust manifold and Garrett turbo running 15psi boost.
-Adjusted LDA star wheel/ boost pin and a bit more fueling (minor adjustments)
-Custom exhaust and downpipe (both 2.5", one resonator only in exhaust)
-GTD injectors (recently rebuilt/tested)
-stock headbolts and headgasket
These tests were performed running B50 (50% homebrew biodiesel). Anyway... Here are the results. The last run was the best with 84 hp and 121 ft/lbs of torque. For the last run, We turned up the fuel just a touch (~1/8 of a turn) and picked up a few more ft/lbs of torque.

These results indicate the power level measured at the wheels, so the owner says to add around 15% on there for drivetrain loss. I guess that'd put me about 95hp and 140 ft/lbs of torque... I was pretty happy about the increase over stock power levels considering that everything is pretty much "stock" except the exhaust. Can't wait to see how the intercooler and eventually a Giles pump changes things.
Those of you that have done dyno runs, do the curves look typical? Torque seems to peak out at about 3300 rpm.
-
#1
by
larry104
on 30 Oct, 2006 07:55
-
That's impressive given that the stock motor made just 68 hp. I think biodiesel has about 10% less energy content than petrodiesel, so you may make (in theory) about 5% more power on 100% petrodiesel than you are now (50% biodiesel). I'd like to do a dyno run with the Jetta when it's all done (Giles pump, 2.25 exhaust, GTD injectors, IC).
Have you figured out your IC yet? I may have something that would work for your setup. I have a Saab 900 IC that's about the length of a radiator with both inlet and outlet on one side. I seem to recall someone on this board using one. Anyhow, I can take some pics of it and post if you're interested.
-
#2
by
veeman
on 30 Oct, 2006 08:02
-
Yes, I was thrilled with the improvement over stock...a bit surprised really. I wanted to do the baseline to somewhat document all the "common" mods that everyone talks about here.
I haven't done the governor mod and I didn't do successive runs playing with the boost pin / star wheel orientation.(Mine were adjusted slightly and I left them like that). I'd love to do that to see if the curves change, but dyno time adds up!
We'll be working on the IC setup this week. I should be able to post some pics during the process.
Your SAAB intercooler sounds like it'd be nice (which model did it come from?), but since I have the starion unit, I'm going to try to use that one. I's about the right size and has metal end tanks. Edit: Here's a pic of the intercooler, although the one I have has the long inlet pipe removed.

Right now, I'm a bit torn between trying to get a different radiator and take the return pipe back out on the battery side or having both the inlet and return back on the alternator side of the radiator. We'll see how it turns out...
-
#3
by
Justin
on 30 Oct, 2006 08:26
-
the B50 in this application will make no difference with the testin that I have seen. if anything it will be a little better, yes its lower on BTU's but the difference in Lubricity are huge and make a big difference on the parasitic drag of the IP.
I tested petro, B5, B20, B50, B100 and straight veg on the dyno and the only one that made less peak power than petro were B100 and SVO, but the torque curve for SVO was the best of any of them
later
Justin
-
#4
by
larry104
on 30 Oct, 2006 08:44
-
the B50 in this application will make no difference with the testin that I have seen. if anything it will be a little better, yes its lower on BTU's but the difference in Lubricity are huge and make a big difference on the parasitic drag of the IP.
I tested petro, B5, B20, B50, B100 and straight veg on the dyno and the only one that made less peak power than petro were B100 and SVO, but the torque curve for SVO was the best of any of them
later
Justin
Biodiesel has about 10% less heat energy/volume than petrodiesel, but it is also slightly more viscous, which, from what I've read boosts injector efficiency, so the actual hp drop is less than expected based soley on energy content. I've also read that biodiesel is less lubricious, not more than petrodiesel, though perhaps not less than the low-sulphur diesel fuel.
-
#5
by
Justin
on 30 Oct, 2006 09:40
-
biodiesel defineately has more lubricity than petrol diesel, especially ULSD, thats why there has been talk about using biodiesel to restore lubrictiy.
in some cases 1%blend of biodiesel can increase the lubricity by 60 fold. I notice a big difference in fuel temps when running biodiesel since it lubes up the pump better
later
Justin
-
#6
by
larry104
on 30 Oct, 2006 10:17
-
very interesting, Justin. Curious why Bosch says not to use more than 5% biodiesel in in their new pumps? :?
-
#7
by
veeman
on 30 Oct, 2006 10:18
-
biodiesel definately has more lubricity than petrol diesel, especially ULSD,
Yes...I've heard the same thing. My engine seems to run quite a bit smoother/quieter on bio and smokes less as well. I drive a lot commuting for work and B100 has made a big difference in my fuel costs.
Thanks for your results, Justin. I originally wanted to do dyno testing with B100 then petrodiesel back to back, but didn't get a chance. We've had some cooler weather lately and I started blending to be safe. Maybe next time... I have a separate gallon tank, fuel filter, lines and banjo bolts ready to go...
-
#8
by
larry104
on 30 Oct, 2006 10:20
-
Your SAAB intercooler sounds like it'd be nice (which model did it come from?), but since I have the starion unit, I'm going to try to use that one. I's about the right size and has metal end tanks. Edit: Here's a pic of the intercooler, although the one I have has the long inlet pipe removed.

Right now, I'm a bit torn between trying to get a different radiator and take the return pipe back out on the battery side or having both the inlet and return back on the alternator side of the radiator. We'll see how it turns out...
It's from a Saab 900.
-
#9
by
veeman
on 30 Oct, 2006 10:39
-
I forgot to add that the caddy was idling at about 925-950 rpm on the dyno and then went up to around 980-1000 when I upped the fueling a bit more. I tried adjusting the idle screw down a bit, but it was already at the limit. Any more and I'd be off the stop.
I'm assuming that by turning up the fuel that last time, I'm at the point where the idle screw can no longer bring the idle speed back down...
-
#10
by
HP
on 31 Oct, 2006 13:18
-
Nice dyno run, veeman. Nice figures.
Do you have an idea or know how many seconds does it take to your Caddy from 0-100Km/h? Or 0-400m?
-
#11
by
RabbitJockey
on 31 Oct, 2006 13:23
-
that intercooler looks like the perfect size for our applications,
-
#12
by
veeman
on 31 Oct, 2006 13:40
-
that intercooler looks like the perfect size for our applications,
I'm hoping that the sizing is ok and not too big... Lots of local VW guys use that in gas applications. A friend put more than 225 hp through one with a 16V turbo gas engine. I liked the solid construction and the all-metal end tanks...plus mine was a steal on ebay for $40 or something.
Do you have an idea or know how many seconds does it take to your Caddy from 0-100Km/h? Or 0-400m?
Actually, no... I've never tested it. I'm not sure my truck is that fast from 0-100 km/h...maybe 9-10 seconds perhaps? My gasser rabbit GTI seems faster, but that could be just a difference in how the power comes on. What I like about TD is the amount of torque that's constantly on tap in most any gear. Makes it fun to zip around town.
Also... I just found one of Jake's 2003 dyno plots from another forum. His results were very similar to mine (his is a 1.6TD with intercooler he used in Solo racing in his rabbit).
I believe he had 87hp at 4750 rpm and 104 ft/lbs of torque at 3750 rpm. Interesting. Seems like his power curve was shifted up 500 rpm from mine. I can post that one to if he's ok with it... Not sure what mods he had at that time. Are you out there Jake?
-
#13
by
RabbitJockey
on 31 Oct, 2006 17:39
-
i just got one for 70 shipped. would have rather paid 40 haha, oh well. i do about 8-10 second 0-60, and a 16.2 in the quarter mile, so i'm gonna guess i am around the same power range, accept i am running closed wastegate at 25 psi, i think you having 15psi though is more of an advantage since your wastegate works, cause if i add more fuel i would just get more boost, i wish my wastegate would work. i plan on pulling the head sometime this summer so i'll have to go over the turbo a little bit then, but i plan on doing a better turbo setup and stuff later on, so no rebuild or anything
-
#14
by
RabbitJockey
on 31 Oct, 2006 17:48
-
the only real differences is that i don't have a 2.5 down pipe, i have the stock cast iron piece plus that goes into a 2 inch down pipe and then into a 2 1/4 exhaust. plus i ahve a k24 with a roughed up compressor wheel.