Duke

Pat, you need to take your car to the strip when it's back together.
Jet951 should do the same. And me too.
Everyone should do it so we can compare trap speeds.

I've never been to the drag strip but I have high expectations for my race car.

333pg333

I would actually like to do this Gustaf. My hesitation has been about breaking things. As it is I spend way too much time on the sidelines and don't like the idea of risking anything else breaking, but you never know. Maybe having a lighter car might lessen the load. I'd love to see what Sean's car would do but I'm betting he's a bit like me. He did a bit of damage once before but that was with a weaker r&p. So maybe one day...can't even get him to the dyno though!!! Love to see your car! I think they'd be a bit shocked if you rolled up to the strip in a full blown race car....that just happens to be road registered!!!

Duke

We can always do a soft start just to get off the line and then start accelerate. If the car cannot handle that it would brake on the first lap anyway
Hmm my car should be around 2530 lbs with fuel and driver. Wonder what the trap speed will be with 500+ rwhp?

333pg333

It would have to be into the 140's wouldn't it?

DanaT

Just dont hammer it off the line and you will be OK.

Trap speed doesn't matter too much how hard you come off the line (I was bogging big time).

-Dana

DanaT

I dont know what to tell you.

Again, this is why I like the uncorrected numbers. I can compare them to a dragstrip.

My first run of the night was on my low boost setting. I ran 103.76. The dyno was 287hp. Using the link that was posted (those numbers seem spot on for rwhp and my car..i need to get the formula they are using) it predicts a 103.7mph run.

If I take the 355hp (i was between 352 and 355 on three runs at high boost on the dyno, plug that into the link, it shows 111mph.

I was screwing around with settings but ran a 110.3 and a 110.06.

I also ran the car on a Dyno dynamics which will give very close results to the dyno dynamics that you ran on. If I was running on a dynojet, you can't compare results.

But if you question is am I really running a 2.5in exhaust, stock intercooler, etc, yes.

Engine mods consist of
82lb (i think) injectors
Vitesse S2R
Vitesse V-flex MAF software (with piggy back)
I have better head studs
2.5in exhaust without cat
Tial wastegate
stock downpipe
stock manifold
stock intercooler
stock intercooler pipes
I have lindsey silicone coolant hoses
new lindsey wiring harness
ice shark cables
Forge BOV

If you doubt this, ask the 951 guys here that have seen the car.

DanaT

Mid 130s

DanaT

333pg333

You seem to be questioning numbers.

Just as reference point, that link is about the most accurate I have ever seen for predicting mph.

Here is a time slip from my hayabusa (I was running next to a Yamaha R6 so you guys can see spped comparisons at altitude). 130.48mph

The dynojet dyno for the bike is 155.1hp SAE corrected. I hate corrected numbers because I cannot compare to real world...but, since they list the CF on the sheet, it is showing an SAE CF of 1.19 for that day (58 degrees out) that would make 130 uncorrected rwhp (but dynojet which are typically a little optimistic compared to an eddy current dyno).

But the bike and I were probably around 725lbs depending upon how much fuel etc (I can carry 40 some pounds of fuel..which changes weight by 5%). Anyways, 725lbs and 130rwhp on that indicates 132mph quarter mile. If I had an exact weight, it would be more accurate.

But all the numbers work out.

DanaT

Just so we dont get confused, lets say 23psi above 14.7 (37.7 psi absolute).

I have two dyno points. 287 at 13.5lbs. 355 at 19 psi. Lets say about 11hp per pound of boost.

So 23 is 4 more than 19 so 4*11 = 44

355+44 = 399hp.

But remember, that I show 22psi on my gauge (I am 22psi above denver atmosphere). This is where the correction comes in. If I show 23 psi at your atmospheric conditions, I would be making close to 400hp but I am only making 19psi above 14.7.

Of course, this again has many variables. What do the pressure ratios look like? Will a 2.5in exhaust start choking power above 355? There are tuning differences between high and low altitude.

333pg333

No so much all about numbers for the sake of it, or bragging rights. More trying to get a handle on why there are so often such differences around the world.
Having the same dyno should go a reasonable way to achieving some sort of parity, but that’s why I also wondered in what mode and ramp rates your operator set the runs at?

As you could imagine, having the mods that I currently have should either yield the hp / tq that it does and others with less mods should show less, or my setup should yield more hp/tq.
Granted, mods alone don’t achieve the numbers by themselves. Of course the tune is integral but I’m sure that the tune on my car is sufficient. I’ve provided mods, chart, and ign table.
What would you expect under these conditions?

Disclaimer: I'm only comparing to my mods because I know them. Not trying to make it all about me. lol. Just asking questions.

DanaT

I know he adjusted the ramp rate a little between two runs. A slower ramp rate would create quicker spoolup but should not affect power readings after spoolup.

What is your question about mode?

DanaT

I really don't know what your mods "should" make.

But I think one thing that is not well understood by many people is having the biggest and baddest parts are not always the best. There are times when combinations are the key.

As an example, a Chevy small. The 327 is just a magic combination that typically make really good power easier than other combinations. The chevy 305 just didn't work well.

I suspect with mine, I am leaving some power on the table with a 2.5in exhaust. As far as IC, there have been many debates if changing the stock IC to "stage 1" or "stage 2" is actually beneficial.

Also, there are some things (which I did not do) that affect dno numbers. I could have iced down the manifold (drag race trick). I have also seen a dyno place that uses a hose to cool intercoolers/radiators during runs.

If you want to put up big dyno numbers, use an air to water intercooler with salt water / ice mixture.

Dana

95ONE

Patrick, You have been fantastic on this forum. I don't think anyone thinks you meant anything more than you just trying to figure out what is going on. It was necessary to write your specs. All understood and well and good.

Unfortunately Patrick, this is what I have been PMing you about for so long. You are truly just not making the power you should. You are down about 40hp. at that psi. End of story.

I Highly suggest doing 3 things. The first one is very easy and may negate the second two.

1. GO to the 1/4mile track like everyone else is saying. That just might be a silly conservative dyno and misleading. You do NOT have to Launch / start crazy. Just give it a wimpy start. MPH is what we need to see and MPH is not affected too much by the starts - it is a little, but no matter what, we all will know right away what your RWHP is (close estimate) If you give us the Altitude of the track and the temp. And the weight of the car with you in it.

You should run between 119-122 mph. at 23psi in that set up. - Giving estimations on your weight and altitude. I ran 124mph with 410 rwph at 2500lbs weight with me in it. I believe you weigh 2700 with you in it right?

If you indeed run 113-115 mph. I suggest the next three things. Easiest to hardest

1. VERIFY your TURBO! You said your turbo was dropping psi at the top end?! A GT3076R would not do that. It has plenty more ceiling to go and would not run out of steam anywhere near that psi. on this set up. I know you think I might be crazy, but verify turbine diameters Inducer and exducer.. Same for the compressor. I work for a manufacturer. Believe me when I say they make mistakes and put wrong parts that are similar, or just get a little mixed up. It happens. And it is Important to check/verify ALL your basics first. It's the best standard I have ever done in problem solving. Be sure of the obvious, is what I like to say.

2ndly. If it is indeed the correct turbo, something else is holding you back. Check everything else. Restrictions, compression, leak downs, boost leaks, etc.

3. Go back to the stock cam. I don't think what you have is helping you out at all. I truly think it is hurting you, especially in a road race scenario. Maybe your set up with this cam actually is the power loss?! Too much overlap and boost is blowing out your exhaust?! Weirder things have happened.

Like I said, you have almost the exact same set up I did. The only difference is the Turbine housing. I had a .63 A/R. I had full 23psi of boost by 3300 rpms. Yours is much laggier, but I think it has to do with other things and not the .82. that might make you lag to 3600 full boost. Right now you're into the 4K rpm range, and that is just not where it should be. Something is certainly wrong there, and I would start with going back to the stock cam. Or just a cam with a little more lift. Don't change the duration.


Patrick, your set up can easily reach 450whp. You paid for it. You should have it. DanaT cannot hit any higher power levels without larger injectors. He truly needs to change them out now and retune if he plans on diving anywhere lower in Altitude. Just for the sake of keeping his motor together. - Dana... you hearing this? And it leaves room for more power in the future of course. Everyone wants that.

Also, the timing tables looked ok. a bit conservative, but good. Rogue? You know way more than I on that one. Suggestions?

95ONE

I believe so. Maybe about 10whp. If you plan on raising boost definitely change out to a 3"-or higher. Certainly larger injectors as suggested above.

I suggest nothing less than a completely different intercooler if you're going to pay that kind of money. It's the stock design that is hurting you at high psi. Not the end caps. Its designed for 12psi. not more. It's a great - incredible design actually - for 1986. There are others out there that will net you some more gains, but it will be minimal, and I think your are right on for changing this out last. For your higher altitude; Thinner core, more surface area. (taller front mount)

Still. DanaT. Well done as is. I will be green with envy on July 9th.

DanaT

I actually dont want that. As long as I have had the 951 (since 98) it has been a fun car. Why did a buy a 951? Because I couldn't afford a 911 Turbo.

Really at this point, to make much more power, takes a LOT of money and i have already put a bunch into having the whole thing rebuilt. But no matter how much money I put into the 951 its not a 911.

If I want to make more power (go faster) that what I have, I think a 996TT is a better start place....

Also, my car is heavy. 3130 lbs without me. I have a roll bar in it. The 5000 way power adjustable recaros are probably very heavy. I run with tool kit and spare tire in it. If I lost 200lbs I would pick up 3-4mph.

Weight loss may be the way to make it faster....