thorzwar

Ok, I'm running a c30-94 rotrex, stock crank to 100mm pulley. Boost is ~10lbs at 7k rpm. Virtual Dyno is showing roughly 185hp and it honestly feels about right. Engine is healthy and unopened NB1 with skunk2 TB/intake manifold, nb2 tubular header swap and catless racing beat from the header back so I don't think flow would be a restriction here and of course all the normal boosted mods (injectors, fuel pump, plugs, etc.). Running MSPnP Pro and utilizing the pre-loaded timing table. Fueling/AFR is happy and appears to be within reasonable range in boost and everywhere else. The engine really seems quite happy, just less peak than expected given the boost level on a c30-94. I can post logs and my tune if there is any interest or if anyone has the bandwidth to provide any feedback. I had assumed that with the 94 it would flow quite a bit more than what I'm experiencing and expected to be in the ~220 range. I'm wondering if this sounds about right to most others with a 94 series here or if I'm leaving a lot on the table somewhere and really need to spend a lot more time with the timing table. Any feedback or similar shared experiences would be appreciated.

Twibs415

iTrader: (8)

Post logs. Or setup pictures

I’d bet the belt is slipping. What does the charger intake look like? Is there a restrictor installed?

other option is the blower itself is broken or on the way out

Ken Brock

Sounds a little low to me. I get 213 whp (on a Mustang dyno) on my 1.6 with a safe tune. Maybe you have a leak?

thorzwar

What size pulley are you running? I’ve checked for leaks and belt slip, all seems solid as boost holds. I’ll get some logs posted here soon, I understand it’s all blind guessing without them.

Ken Brock

I honestly don't know for sure. I bought the kit from Track Dog. I believe it is an 80 mm pulley

thorzwar

It will say on the front of the pulley. Mine is also a TDR kit. Are you sure yours is a c30-94 and not the 84 or 74? Stock crank to 80mm pulley is a ton of flow on a 94, are you running a restrictor?

andym

What does your timing map look like?

rascal

I would be putting the car on a proper dyno to confirm the 185hp reading is true first before I wasted time trying to find an issue that potentially may not exist?

thorzwar

Here is my current timing table along with a few logs - I'm using the timing table from the DIYAutoTune basemap and is untouched since it was loaded, timing is the only thing I haven't tried to tune yet. I also attached 3 logs of various pulls from a quick outing today. Car feels good just weaker than expected for running a c30-94, maybe that's just how the rotrex is but I figured it would be a good idea to have people that know a lot more about this than I do take a look at the logs and timing table to make sure I'm not doing something incredibly dumb or leaving a lot on the table. As always feedback and any input is certainly appreciated.

der_vierte

Wow, that timing map is gross...

I mean, it should make some power, could be a little more with more timing up top, but otherwise it's agressive (around idle) and VERY tame at around 100-150kpa. Kinda all over the place.

Start with a different map, maybe take a look on brains basemap from trubokitty, you can export it from there and import in your tune.

Report back!

Ken Brock

You were right, it is a 100 mm pulley. It is the c30-94 - I think that is all TDR uses now. I had the MSPnP 2 professionally tuned. The tune made all the difference. Don't expect some type of huge rush like you get with a turbo car. It is just a strong pull - feels like a bigger NA engine to me. Redline come quickly but power is very linear and easy to control

Jerryg

Ken I'm running the C30-94 on a built VVT motor using 84mm pistons with a 8.8CR and a squaretop intake. It came from TDR with a 94mm pully and I'm using an ATI damper which is a little larger than stock and I'm making 13psi at 7K. I'm running a very conservatives timing map and on Virtual Dyno I'm making 245 RWHP.

emilio700

iTrader: (3)

Perhaps I missed it but what fuel/octane? Rotrex likes timing.

Agreed with others that its well below what it should be. A real header would make a big difference though. You stated "unopened" NB1. I'll assume this is a high mileage OEM build that isn't currently burning oil. Typically high mileage NB1's don't have great compression.
Fully rebuilt NB1 with 190psi and <3% leakdown is great. 100k mile 160psi, 10% leakdown, not so much. Which is yours?

We have two data points in our shop cars:
C30-94 geared for 14psi @ 7,000rpm. OEM rebuild NB2 with square top RB header and RB exhaust, 2.5" metal core cat on CA91 gas, BOV on intake manifold to bleed down to 11psi. 260whp Dynojet
IIRC I had max timing at around 15°, pretty conservative

C30-74 geared for 10psi @ 8,000 rpm, full race 1.9L NB2, CNC +2 O/S valves, Tomei Cams, RB header, RB exhaust, no cat, E85, 300whp/ 220tq dynojet
Max timing was 21°

ohnoitisnt

Signed up to say thanks for this
What pulley sizes are you running for the c30-94?

260 whp at 7k at 11psi on a dynojet with 15deg of timing is not to be sniffed at

emilio700

iTrader: (3)

I don't recall, sorry. That set up was sold a few years ago. Anyway, you can use a calculator to determine what pulleys you need for your redline. The 260whp build was geared for 7,000 redline but well below max blower speed.