An e-mail received from Speed-O-Motive:

Aubrey! First of all I don't consider you to be stupid or dumb. There is
no
need to cancel your order because of some people on a chat room. Our dyno
work used to be sublet on a Super Flo. dyno. They correct their own air temp
& barometric using there own factor.
We have since bought our own in house D.T.S. dyno.. They correct at S.A.E.
industry standard of 72 degrees at 29.92 barometric pressure. D.T.S. gives
us a correction factor of 10.3% to reconcile the D.T.S. observed hp to the
advertised Super Flo numbers.
We do the dyno work for Super Chevy Mag. on the Danger Mouse engine,
evaluating mfg's products every month.
We were given this because of the accuracy of our dyno.
I answer to the Guy that is in Garden Grove if he can give advise to you he
should be able to visit our dyno room, we dyno every day and welcome
customers to see their dyno pulls.
I have a spotless reputation, I made my living drag racing for 13 years and
I sure none of your chat guys can say that.
Most are bench racers. I have a stocker that runs in the 11's. I have a
super gas car that will run in the 9's.
Your getting the benefit for my experience with out the testing, We do our
best to help every customer before during and after the sale.

I find it hard to believe you would take the word of a chat room over a
company the sell's approx. 5000 engines a year all over the world. I agreed
to give you a 569hp engine, I am sending you a 593 hp engine. You said you
wanted a street driver and thats the way I went about your deal.
Our engine D.T.S. dyno does have an automatic computer the figures the
correction when the engine is running. We don't have any reason to give you
or any body else bogus numbers, we stand behind all our product. We are not
a one shot mickey mouse so called speed shop. We are a multi million dollar
Corporation. We have 5 engine builders that are fully qualified to the race
engine part of the business. I'm sure you know that we've been business
since 1946 that in its self would tell you we deliver a good product and
service to our customers. If we didn't give the right product we would not
be in business for very long.
I would bet that all those people in the chat room have not dealt with us
and can't really say anything bad about us. Most of all please think about
what I've said. Your just getting started with this so bet with me and
you'll be a happy hot rodder.
I don't need to hurt people to make a buck. I retired from the auto industry
after 35 years, giving the public a fair and honest person to deal with.
Mike Ostling

Well? I don't want to turn away the engine if it in fact isn't a lie, what do you make of this because this is way over my head now with all the DTS and SAE stuff. Do you think it's just more sweet talking so he doesn't lose a customer?

i find it interesting that he thinks nobody but himself knows anything about dyno numbers and correction factors. if he can guarantee you that it will make the 593hp, then i'd think about going ahead and getting it. i would like to know why an engine of that many cubes built for a street car has such a peaky powerband though. most street motors i see have almost 2500rpms between peak torque and peak hp. i mean launching at 4000 and shifting at 5500rpms seems pretty narrow to me. but i guess the torque curve is pretty flat though. :confused:

I havent followed all of the posts..but I did here you asking ED for BSE advice on another board..The SOM sound sencere enuff,,and if he is promising in writing a 590+hp engine with a warrenty...and for the price you wanted...sounds like you cant lose

Yea that's what I'm starting to think too, but he knows I'm not gonna get it re-dynoed so if he's lying I'll never know. And yes, I was asking about the BSE, lol, when worse comes to worst you have to go to the dark side sometimes. Anyone know what he's talking about with the S.A.E. and D.T.S. correction factor stuff???

Originally posted by aubreyt213:
Yea that's what I'm starting to think too, but he knows I'm not gonna get it re-dynoed so if he's lying I'll never know. And yes, I was asking about the BSE, lol, when worse comes to worst you have to go to the dark side sometimes. Anyone know what he's talking about with the S.A.E. and D.T.S. correction factor stuff??? DTS Is Dynamic Test Systems & that is the manufacturer of the dyno they use.
SAE is Society of Automotive Engineers
The SAE correction factor he is refering to is the SAE one I am assuming & it means the HP & torque should be corrected to 29.6 baro & 77deg.
I don't have a clue what the 10.3% deal is as a dyno does not measure HP it measures torque, not HP & hp is calculated from that by the formula that was previously posted.
There are two standard correction factors & almost all performance shops & published HP numbers you see use the same one Super Flow uses.
It is 29.92 & 60 degrees
The other is the SAE J-1349 & is 29.6 & 77 degrees & I believe the difference is about 4% but not sure on that.
You can use either one on a SuperFlow or any other dyno that uses a computer to gather data by changing the correction factors in the software.
The observed data has got to be corrected to some standard to be of use to most of us & absolutley must be corrected to a base run if you are changing things unless you can control the atmosphere, temp & baro. in the test room which some NASCAR teams can now do.
In any event, The formula for HP is
HP= torque * RPM / 5252 & as far as I know hasn't changed which means HP & Torque should be the same at 5252RPM :D

SAE = Society of Automotive Engineers.

5000 engine a year by 5 builders, 1000 for each, 200 workdays in a year that 5 engines a day. Actually, I know one of the builders. He's very conscientious and would build a nice engine. I don't know about the others. About a year ago, S-O-M revamped their engine shop. They could be doing good work now.

Pat..I read that as he has 5 performance builders...probably has 120 rebuilders to throw most of their stuff together...

Aubrey, I don't buy it.

There have been some very good responses on DRR, I like the one with the 454 block, oval ports, yada yada yada.

I think I posted my entire combo on a post here, I will try to find it for you. $8500 carb to pan ready to start up.

Aubrey, the man from Garden Grove will talk to Mike Ostling tomorrow, about your engine and another SOM engine while I'm at it.

Just a refresher, here's your dyno sheet
http://groups.msn.com/ChevyMonteCarlo/aubreys71monte.msnw?action=ShowPhoto&PhotoID=476

What I want you to first note is that your dyno sheet already lists torque as C_TQ which means the torque figure has already been corrected once. Whichever one of the correction factors was used (like that Mike Wolfrace listed, or the one Mikle Ostling listed) should settle the matter. I too believe the two stndards of correction to be within a few percent of each other (I would have to research the actual % difference). Like has been said, a dyno measures torque, horsepower is a derived number using the science formula of (tq x rpm)/5252. I have over 100 engine and chassis dyno printouts from my engines and cars over the last decade - in every case the hp and tq follow that same formula. There is no reason that I am aware of to first correct the tq to one of the standards and to then further correct the hp beyond the derived (tq x rpm)/5252. One sure way to spot a suspect dyno result is when the hp and tq do not match at 5,252 rpm, please note that your dyno sheet fails that basic standard. I've never had "double" corrected hp on any of my dyno runs.

Now I must say that SOM's reply to you has me puzzled, follow me on this:
1) Your engine was dynoed on a Superflow dyno, SOM now has a DTS dyno. Superflow's correction factor gives the highest hp, so your engine would make even less on a DTS dyno.
2) I'm curious about the mystery correction factor used by SOM's sublet shop.
3) I believe he is right when he asks why you would believe a guy in a chat room over the word of an ongoing business enterprise. Likewise I ask why should we believe the dyno printout he supplied when it does not follow the conventions held by most of the rest of the industry?

Tomorrow suddenly got more interesting, I'll post back how he answers those questions.

Thomas

Hehehehehe, I can't wait! Make sure you remember every last word between the two of you. BTW he is usually only there in the mornings, I think he leaves around 12pm-1pm ish, so make sure you catch him. Make sure you mention my name as well :D But I am so confused right now!! What am I supposed to do, the engine was shipped out last friday. I wish there was some true way to find out if this is BS or not!

Same story, different vendor? I hope not, but the response SOM sent you sounds a lot like my conversation with Bill Mitchell when I tried to cancel my engine order last year.

5000 engines per year, multi-million dollar operation, blah, blah, blah. Most real live business folks would characterize that type of operation with actual revenue metrics - $20M, $30M, or whatever per year. My antennae went up as soon as I saw 5000 engines per year and "multi million dollar Corporation". "Multi-million" is generally used when referring to annual revenue of less than $10M. 5000 engines and less than $10M per year don't jibe. Maybe it's not that guy's job to properly characterize the business to customers, but it's something I try to pay attention to now. Edelbrock is one of the largest companies in the aftermarket industry and their annual revenue is only around $120M.

You may or may not have been trying to do get to the point of cancellation as I don't know the history or your deal, but I got a real sick feeling half way into my BM deal. Because of the honest, experience-based feedback from people on boards like this I tried to unwind myself from a bad decision. Long story short, they wouldn't let me cancel without taking a 30% hit. Eventhough my engine was a catalog number they claimed it was "custom built" and therefore could not be resold as a stock item. Hindsight is 20-20, I should have taken the deal. Instead I took delivery and the rest is an ugly piece of history. Within 200 miles the engine had to be pulled and torn down - what we found was frightening - tolerances way off everywhere, lots of corner cutting. So, I shelled out another $4K to have it rebuilt by a REAL engine builder - an independent that does do them one at a time because he has this really strange idea - he has pride in his work and wants to build each engine to perform EXACTLY as agreed and he kinda likes to build them so they hang together for a long time.

If your engine is coming with a warranty, get a copy of the entire agreement asap. What I found in my warranty doc AFTER I got the engine was a complete joke - totally useless. The sad part about that is the "insurance-backed 2yr/24K mile warranty" was one of two reasons I went with BM in the first place.

I may be totally off the subject here but was wandering by and saw the diatribe from SOM to you and thought I'd chime in. SOM may be a totally righteous builder. But for me, I will never, ever, ever buy an engine from a production house again, except for crates that come from GM (ford or chrysler).

I learned my lesson. It took 3 times longer and twice the dough to get an engine from BM that I could have had any number of good, honest independent shops build for me.

Best,

Mike

Bomber67, did you ever make it into SOM today???

Race Report (phone conversation) with Mike Ostling at SOM this morning:
He is a nice guy to talk to, I was suprised about the amount of telephone time he was willing to spend in conversation. Really, I enjoyed talking with him and believe he is very interested in SOM being seen in the best possible light. He invited me to come to the shop and see the $500,000 in new shop equipment SOM has purchased since mid year 2000. He talked about all the changes in process and people that had occured since 2000 to bring more quality into their finished product. He also said I was welcome to come sit in through a dyno session anytime I wanted. Mike has logged onto Team Chevelle and shared with George (SOM owner) what was being said about SOM and their dyno results.

Okay, onward to the main point for the call, which was my questioning the validity of the horsepower side of their dyno printout for Aubrey. He went on to explain all the money (~ $100,000) that had been spent on getting their own in house DTS dyno room built, and how SOM had previously sublet dyno work out to a facility that used a Superflow dyno. He said that Aubrey's engine was dynoed on SOM's new in-house DTS dyno. He made no claims for being great in the math behind the dyno, instead he asked if I would call DTS and see what they could explain about SOM's dyno numbers vs what I thought they should be. I told him that I thought that after spending that kind of money I would have expected SOM to be interested in why their dyno numbers didn't follow the same conventions that others did (I.E. - that the derived hp at any given rpm was: torque x rpm all divided by 5252). He talked about correction factors and suggested that maybe DTS was now doing things differently than what I had seen. I mentioned that ~ the last 50 engine pulls I have done were all on DTS dynos (three different facilities), and all had followed the hp derived from torque in the same manner that I had learned in school. I told him I didn't think DTS had rewritten science, and certainly the formula I was using was not of my own making. In a way he really seemed to be suggesting that this was the way of the newest DTS dynos, and that I really should be bringing up my concerns with DTS. He had DTS's phone #, he gave it to me, and I called DTS up. I talked to Dave at DTS (President?). I told Dave I was calling specifically in regard to the DTS dyno at SOM, and what I felt were puzzling dyno results. Dave was naturally very aware of the basic math for deriving hp from tq. Dave then talked about correction factors and how everything was corrected - hp, even though a derived number, is by default corrected because it is derived from a corrected measure of torque. I asked him if DTS had changed anything in regard to torque and hp crossing at 5,252 rpm. I explained that I was asking because the SOM dyno sheets were showing crossover at ~ 4,700 rpm. Dave asked that I fax over the dyno sheet(s) so that he could see this himself. Dave also explained that DTS software allows the operator to change just about any formula for measuring and or correcting any output that appears on the dyno printout. Dave said this allows a dyno operator to change the formula for any measure of output is there for any kind of testing an engineer might think of. Dave also said that OEM's will have engineers spend the time to develop correction factors for a specific engine - not all engine designs will fluctuate the same way in power over a range of weather and altitude. He further noted that custom performance shops generally only use one of the standard correction factors for all of the engines that they dynoed. I got Dave's fax number and thanked him for his time. I then called Mike back and said that Dave wanted to have the dyno sheet faxed over. Mike said he would fax it and see what DTS has to say in reply.

*Commentary* I thought about my conversations with Mike and Dave, re-read Mike's email to Aubrey, and thought about the competitive environment of custom high performance engine building. I know that the Superflow dyno, and Superflow correction factor, is acknowledged to give the highest hp readings vs a DTS dyno using one of the other standard correction factors. With the emphasis on appearance, it appears to me that SOM feels that the Superflow dyno reads 10.3% higher than the DTS dyno. Remember that this is a competitive environment where SOM has to offer engine packages with other competitors, many who are using Superflow engine dynos. Now enter the consumer who demands the most power for the least amount of money. How to remain competitive in the price vs hp conundrum? How about advertising your engines based on Superflow hp figures?

P.S. Just for fun, every time you read a magazine article where they express great suprise about how much more hp a particular factory crate engine made over the manufacturer advertised claims tell me if you don't see what I see: power measured off a Superflow dyno, or corrected to the Superflow standard.

P.P.S. This is why we don't race dynos. Dynos are great for comparative testing of a series of parts or tuning changes - but the bottom line is what happens after we bolt said engine into a car and actually run it down the track.

Sorry for all the words, I hope it was worthwhile for you to read it.

Thomas

WOW. Thank you SO much, I can't tell you how thankful I am to have you go out of your way like that and make all those phone calls and spend all that time on the phone like that. That is VERY much appreciated! So what you are basically telling me is that my engine was dynoed on a DTS and had a Superflow correction factor or something so thats what it would've read on a Superflow dyno? Does this mean this is how much power it really makes or is it inflated by 10.3% over what a DTS dyno says, and DTS being of the highest accuracy? So the basically the engine makes 526 hp? You think I should take the engine then??

P.S.
Thanks for all that research Thomas, very much appreciated!!!

The Superflow correction factors of 29.92 & 60 degrees are pretty much the industry standard corrections for performance testing & have been used for quite some time.
The other is the SAE correction factor of 29.6 & 77 degrees.
The Superflow one will give higher HP numbers & you cannot compare the two directly. You have to compare apples to apples.
I am well aware of some of the "generous" numbers some dynos seem to make but I believe if the same correction numbers are used on different dynos correctly the numbers will be reasonably close.
I do not think you can use one set of corrections & just add another 10% to them & call it any kind of accurate & no matter what corrections used the same torque & HP relationship should still exist. That being
HP=torque * RPM/5252.

From what Thomas has posted it sounds like you are getting an engine from someone who cares very much about his product.
The DTS dyno is an excellent piece & very expensive & I doubt he went out & bought it just to impress people. I just disagree slightly with the way he tests.
I do believe DTS uses different formulas for friction HP than Superflow & this could account for some difference on corrected numbers but I highly doubt you would see 10% on the two different units if all else was equal.
That being said, I have seen 10% difference between Superflow dynos at different facilities.
I had the opertunity to dyno an 18deg small block that was tested in a facilty in the LA area & in the SF area on a dyno that is considered "conservative" as is mine. As I recall, it was down some 30-40 HP on the one in SF & about 50HP on mine. This was on a 670hp or so engine.
And as has been said many times,,,, we don't race dynos :D

Aubrey, all the answers to your questions are in my previous post. Yes, I was told your engine was dyno'd on SOM's new DTS dyno. Based on my conversations and the email from SOM you posted above, I believe that it *appears* SOM is further correcting the DTS derived hp to be similar to the Superflow power figures that many of their competitors use (and for that matter that SOM used in the past from the sublet Superflow dyno facility). It appears that SOM feels the Superflow numbers are 10.3% greater than the DTS numbers. Let me emphasize "appears", because I do not know what transpired between SOM and DTS after I passed on the request to have your dyno results faxed over to DTS.

I have no idea exactly how much power your engine will make - remember I said it "appears" to me that is what kind of hp correction was done. What I can tell you is that SOM has been taking the neccesary steps and putting forth the effort to build a much higher quality engine than they were as recently as just four years ago. SOM operates in a very competitive environment with hard shopping customers. All similar vendors are always looking for a way to deliver more power for less money. One of the possible ways to do this is to use the standard that gives the highest hp numbers. Remember, we don't race dynos. Here is a real world example I want you to think about. When I acquired my '65 El Camino it had a tired 468 that only showed 368 rear wheel hp. Race weight with driver is just a tick over 3,600 lbs. Yet those tired 368 ponies ran a 12.02 e.t. @ ~ 112 mph on my first pass with the car. That is faster/quicker than might be expected given the measured power, my point is that any particular measured number can be subjected to all the math you want - bottom line will still always be actual in car performance.

Thomas