I was finally able to get the car on the dyno today on my lunch break. I didn't have very much time to dial in the tune, but I did make some pretty substantial gains.

Initially, I was disappointed because the car was only making 340 RWHP. With the 118 MPH traps is was turning last weekend, I expected about 370 or so.

Anyway, after some rough tweaking it made 389 RWHP. It's still rich (12.2-12.5) and still only has 32 degrees of timing in it, so I'm pretty sure there is another 10-15 in it, but I'm satisfied with the numbers considering I only had about 30 minutes with the car.

I plan to hit the drag strip this weekend (assuming my checking account can stand it) and then get one more session on the dyno when I have more time to really dial the car. I expect low 400's from the combo once it's squared away and low 120 trap speeds.

Tall order for the AFR heads, no doubt. I still think they will make more power, but I don't think it's going to be by a tremendous amount.

I'll scan the graph and post it tonight.

Thanks for the update. Those are good numbers. I agree with a little more tuning you should be able to squeeze a little more power out of it.

Good numbers so far!

What "rough tweaking" did you do in 30 minutes that took you from 340 RWHP to 389 RWHP? I wouldn't mind you spending 30 minutes with my car!!!

I'm assuming the numbers were on a Dynojet, SAE corrected? I would like to get my car to a dyno this summer sometime and I want to compare it to your 2 setups. Mine isn't all that different, with HSR intake instead of miniram, similar duration cam (only mine is with less lift and is flat tappet), and I have the AFR 195 streets. I'm running a 700R4 slushbox though. Just curious to see how mine compares later this summer.

As a side note, I'm not dialed in 100% yet either but I'm running the same quench distance as you on the 195 streets with JE flat top pistons (ends up at like 10.7:1 SCR), I think my dynamic CR is higher than yours, and I'm currently getting away with 36.5 degrees overall timing. I'm running RC9YC plugs which are a little cold, but need to be there for nitrous use. My air fuel ratio starts at around 13.5 when I first hit WOT and slowly creeps down to about 12.4 right before the shift. No detonation so far, just wanted to let you know, maybe you can push the envelope quite a bit yet.

My dynamic is about 9.1:1, I don't remember what yours was.

I was able to watch my timing with a light today while the engine was ran to redline at WOT. There was a significant difference in the actual timing VS what was the tune was supposed to be commanding. If you are rocking 36 degrees via tune, I wonder what it actually is? I can't think of a way to check it other than on a dyno, but maybe you can come up with something. I think for the most part, as long as your base timing is correct, commanded timing and actual timing should be really close. Mine wasn't, and I don't really know why.

As far as pushing the envelope, I don't know about that; but I'll run it pretty much to the ragged edge. I'm not going to break records or anything, but I can promise I'll get everything out of it as far as the tune is concerned. I just need more time to dial it in.

As far as changes, just fuel and spark. No rocket science there.

Nice #'s

It will be interesting to see what the new ET will be.

Those are good numbers, both MPH and RWHP wise. I think its got about 15-20ish RWHP left in it as is.

I too think the AFR's will do a little bit better.

I'm not trying to toot my own horn - Just trying to give you something to go by.

The LT4 I built for Noland Smith went

****EDITED TO CORRECT****

383.2RWHP@5400RPM (Dyno Jet SAE Corrected)

His motor has AFR 195 Comp Port Elims, a port matched LT4 intake, 10.8SCR (8.5DCR for his 89 octane fuel requirement), a Reed Hyd Roller camshaft that is very similar to your Comp 280XFI. That's thru a 6spd, using EM long tubes, Random Tech Cat Converters and a Power Effects exhaust. I'm sure there a bit more in it now the miss is fixed but he's not interested in re dynoing it and telling everyone what it actually has.

I'm really glad to see this comming together so well for you Josh.
Will

what about the rwtq numbers?

No offense Will, but in my opinion the car you are talking about didn't make the numbers you are claiming. I don't want to muck up this thread talking about it, but I think there is a problem with your claim. I'll shoot you a PM and let you know why I think that.

However, I think I should be in line with the numbers you are suggesting. With some more tweaks, 405-410 is what I expect with the current combo.

Great #s, can't wait to see the comparo.

Matthew

I have checked idle and at 2000rpms in neutral with a timing light, and Tunerpro real time datalogs show the exact same whole number that the light is calling for. Of course the light doesn't show decimals. Odd that yours is different, if you find out why let us know.

Will be cool to see how much ET and MPH you picked up by tweaking the timing and fueling. The feedback you are giving us is awesome.

I kind of figured you would run it to the ragged edge, I just stayed conservative saying "pushing the envelope". I also think it is awesome that you can put 1/2 hour into your car and figure out that much and make it that much better. It takes me that long to decide if I want to do something or not!

No scanner, but here's a digital pic of the graph:



Another



Before someone asks, I did not make 28 pulls on the dyno.

Quote:

If I figure it out, I'll post the solution.

Quote:

I appreciate the props, but it's not anything you couldn't do if you chose to. Hell, anyone on here could do it.

I'm going to try to get one more dyno session in, really nail it down, then hit the drag strip one last time before swapping to the AFR heads.

Guys who have donated, I really appreciate it. The dyno time alone is going to be over $300 by the time I'm done, let alone all the incidentals associated with the swap. Others interested in donating can do so here:

http://www.corvette-guru.com/modules/ ... php?topic_id=7380&forum=1

If any of you are ever near Raleigh, NC; even if you just have a long lay over at RDU airport, let me know. First round is on me.

Thanks again guys, it wouldn't have been possible without the help.

very interesting stuff.

Any new updates on track times/dyno #'s or when the AFR's are going on?

I'm not real sure when I'll be able to get back to the dyno or drag strip. I'd like to hit the dyno before the track, just make sure the car is dialed, but I'm not exactly sure how the whole thing will work out.

I would just tear the heads off and stick the AFR's on it, but I don't feel that I've gotten 100% from the the combo as it sits. Once I feel like I've gotten some honest numbers from the TFS set up I'll start the swap.