So, I have a question for everybody that's more opinion than anything...

I recently had my car dyno'd on a "dyno day" type event. I paid for 2 pulls and received 7 pulls back-to-back because they couldn't keep the transmission in 3rd gear as it kept wanting to downshift into 2nd.

So, 7 pulls without a fan blowing on the car (Brand new dyno, didn't have a fan yet) and on a 34*C/93*F day, how inaccurate are these numbers? If you can't see the chart, it's 212HP and 278TQ.

I was told by the guy doing the dyno that the numbers were out to lunch and the car was pulling timing but he needed me off the dyno and he couldn't keep trying to dyno proper numbers as there were a lot more cars that had to be dyno'd that day.

Here are the charts:



My mods to my 2003 Monte Carlo SS are as follows:
3.6" Pulley with 0*KR ZZP SSM90 Kit with GTP injectors
Ported/polished heads
polished piston tops
L36 Ported/polished/half-shafted throttle body
10.5” Coned air filter directly on TB
Homemade plastic TB spacer (This made a huge difference in throttle feel and response by the way, felt like the springs were heating up and losing tension before this mod)
180* drilled Thermostat
Waterpump underdriven 5%
Fuel pump rewire
Alternator B+ rewire
ZZP 10.5MM spark plug wires
Autolite 104 spark plugs gapped to .048”
L67 Coil packs
ZZP 1.0 PCM
ZZP front and rear PLOG headers
U-Bend delete
Resonator delete
2x - Flowmaster 40 series Delta Flow mufflers
Short stack intercooler
FloJet intercooler pump
Dual pass heat exchanger
Transmission cooler
TransGo shift kit
L76 Valve springs
ZO6 Valve spring retainers and locks

In addition to all of this, I pulled the entire motor apart and chem-tanked EVERYTHING plus replaced every worn part and all sensors. I currently have 3000 Kilometers on this completely rebuilt motor and it feels strong as hell.

Everybody that drives in it dispute my dyno charts and when I got my car dyno'd my friends at the event with me were more peeved than I was about the numbers because my car spanks all of their cars and they all made far more power on the dyno than I. I felt pretty good that day actually, despite the inaccuracies. lol.

I have since upgraded to a 3.4" pulley and still seeing 0*KR everywhere on 94 Octane gas. Made a nice difference in power.

ANYWAY, TL;DR

Dyno chart is inaccurate, what is your best guess on how much power I should be making based on my mods?

THANKS EVERYONE!

 

I don't think the dyno is inaccurate. No doubt you've got some low numbers, but on a heat soaked setup after 7 runs on a mid 90s day, I would expect the number to be getting pretty low. Its just not going to be a record run for your setup with such poor conditions.

The other thing to keep in mind is that it's hard to compare exactly across dynos on the Internet. It's more helpful to compare before/after changes of the same car on the same dyno.

​​​​I don't know much about your particular setup, but I'd imagine that setup could do 250 whp with a good tune. The mod list looks long, but a lot of that stuff adds basically no power.

I think one of the big killers is the pulley size. The blower speed is the largest contributor to how much air the engine can flow. A 3.6" is pretty big, almost as big as a stock L67 that would be lucky to put down 200 whp in the best scenario. I get you have higher compression and some other mods, but there is only so much you can do with a given volume of air being pushed in.

You're definitely on the right track with the 3.4". I'd keep dropping until you get knock and then either go up a step or pull a little timing depending how much you've got in it.

Also, id reconsider the plogs and short IC. Full headers and a full size IC (along with a small pulley and retune) would definitely help pick up more power.

 

Yeah, the dyno guy said I should realistically be seeing 250whp, as also said ZZP and a local shop with a dyno.

My tune on my computer shows 16.5* timing advance at WOT and with the 3.4" pulley I see 8 psi boost at redline.

I'm really just learning and testing things on this car. I do everything myself and have completely restored the car from the ground up. I never intended to do any power adders in the beginning, but after I ran out of restoration mods, I had no other choice. lol. Overall, this car has never let me down and because I've done everything myself, it has cost very little to build. (I'm just at $9000 CAD including the cost of the car spread over the last 3 years and a bit. No loans or anything. If I don't have the money, I don't play.)

I would be more than open to any suggestions going forward from here.

What kind of headers? How much better would they be compared to the PLOGs + 3" DP combo I have now?

Also, I already have an intercooler. I have the SSIC. Would love to do full stack, but my injectors are in the intake manifold and it's tricky-dicky as it is with the supercharger on there.

I run a 50/50 mix in the heat exchanger, would a 70 water/30 coolant mix be better?

 

Id think you could pick up some power with more timing too, especially since you're not seeing any KR. Of course you'd need a way to tune it, but that would let you dial it in a little better.

There are a lot of different options out there, ebay, pacesetter, tog, zzp, etc. Each has a different cost and slightly different benefits. In general the big benefit will be in the longer primaries though. The upside is that you could sell your current parts and could come out near a wash with cheap headers (which is why many people go straight to headers).

I didn't realize you had a DP already. I saw u bend delete, but was thinking you still had the stock restrictive DP inlet. I don't think the power gain would be huge at this level, but it depends how much further you want to go.

Depends where you live and how much freeze protection you need. I don't think you'd see a change in power. The limitation is quickly going to become that tiny SSIC core. You can only pull out so much heat given such a thin core.

Doing that many pulls, the volume of coolant in the system gets to be important as well. The HE can only dump heat so fast, especially on a dyno with limited airflow, so additional coolant volume in your IC system will help it resist the change in temperature better.