Andreas

the Pettit conversion and the costs...

- better drivetrain
- better handling
- great looks
- great engine which will last a long time with the standard boost setting
- enough potential for high horsepower numbers
- love the sound, can't beat it

i think it's just a very good package with value for money.
and for the money, what does e.g. a 911 turbo cost?

just my 2 cents

weaklink

David, I'm not knocking your car personally. I followed this thread with great interest. I was just a little disappointed with the outcome. I'm sure you're happy with the car and as long as you feel the money was well spent that's all that matters. For me, the ends would not justify the means. I guess I was just thinking out loud and didn't mean for it to be regarded as a slight. I apologize if any offense was taken. It wasn't intended.

FDNewbie

iTrader: (10)

I think what David's been trying to say is, it's not finished yet. He's sticking w/ the 350ish hp & torque for a bit before upping the boost in. Heck, consider it another break-in period I'm sure he's going back to Cam soon enough to up the boost in a few, and make some impressive numbers on stock twins very reliably and w/ tons of torque that 13Bs struggle to even attempt...

David Hayes

iTrader: (6)

No offense taken. I certainly understand your viewpoint.

HDP

iTrader: (2)

I understand the power potential is there, I'm just wondering about the creature comforts that he was expecting but now do not work. If the A/C will no longer work properly with the Wolf unit, why is it advertised as doing so? It's a complete conversion package, right? If something in an advertised package is not working (especially something as important as A/C in Florida), IMHO, the package is not complete. They could have saved the trouble and removed all the A/C components to save the 50-60 lbs of weight then he would not have the expectations of a working A/C system. For me personally, I would not want a street driven car (not a race car) that did not have A/C. I know I will get bashed for saying that (ie. real sports cars don't have A/C) but have you ever tried to drive a car with no A/C in the middle of summer to a wedding wearing a tuxedo? Trust me, you don't want to... And isn't that the entire purpose for going this route for the conversion, to have a STREET driven car with ALL the comforts and performance in a complete package?

FDNewbie

iTrader: (10)

I feel you. If it were me, I'd be pretty adamant about making sure the small probs were fixed and ironed out, esp. after dropping thirty five large. I'm also a big fan of A/C. It's simply very impractical to go w/o A/C, esp. when the only time I drive my FD, it's hot out And yes, that's def. the goal: a street driven BEAST that can still retain all the comforts

Red-Rx7

I think it is great to see another quality car completed; but I am also disappointed in the numbers. I know the numbers are not everything, but it is a big part in the whole reasoning of doing it all. Reliability is subjective to the tuning, not necessarily the boost. Our engines have the same inherent issues at 10psi and at 14psi.

The additional torque makes the car feel like it is a complete different car. It is amazing to have the very low end torque, and it does feel good. Yet, if I were in your position David, I would start to wonder if that extra grunt was worth the actual cost? Right now, of course it makes since to you, because you just took this plunge. Trust me, I know how that feeling is. I don't know if it is just the new '20b denial syndrome', but are you really content with those numbers?

David Hayes

iTrader: (6)

Sorry for the confusion, but the AC does work. The problem has been fixed. Should have made this clearer. I'm big on the creature comforts and trust me, everything has to work on the car. And it does. Not having AC in Florida would suck bad.

ptrhahn

iTrader: (9)

I wonder if the twin turbos aren't really to blame. Much has been surmised in various threads about twin turbos (usually related to upgraded twins, like the BNR's), and many have concluded that, regardless of the upgrade's to the turbo units themselves, the associated twin turbo sequential manifold will only flow well enough for X horsepower, usually figured at about 380-400 tops.

This car is attempting to flow three rotors worth through the same log. 10, 12 or 25 psi, It seems as though, if that's a bottleneck for a 2-rotor, it would be more so w/ a three... and more for peak horsepower than torque (something dave's numbers seem to express).

He is still making about what a similar 2 rotor setup would produce at 15 psi, only at 10 psi... and gee, that just happens to match the proportion of three as opposed to two rotors.

David Hayes

iTrader: (6)

I was going to use your car as an example of the HP capabilites of the 20B! No, I'm not satisfied at stopping at 10 PSI. 385 RWHP and 365 torque at 10 PSI is pretty good but I definately won't stop here. There is no reason why I can't turn up the boost and get better numbers. My point was that I'm just going to enjoy the car for a short time and make sure everything is okay before doing this. I've got a great datalogger hooked up to a wideband that will help me in this effort.

So, everyone chill for a few weeks and I'll be back! Almost feel like I should have said nothing and waited until then but I wanted to let everyone know where I was with the project.

HDP

iTrader: (2)

Good deal! If I were you, I wouldn't pay any attention to what everyone is saying about HP numbers. The potential is there for the goal you have in mind as long as the remaining tuning is INCLUDED in the initial cost, you are set.

Red-Rx7

Yes, that is one of the caviats with a forum. With so much interest in your project, everyone lives vicarously through you! Maybe I misread an earlier post, but I was reading it under the impression that you were content with the numbers, and were going to leave it be as is.

I understand the feeling of being "defensive' too, for I would be as well if people expressed disappointment with MY car. Hell, it is MY car, and I built it for ME. With that said, it isn't fair for ME to be dissapointed with YOUR car. But, because everyone lives vicariously through you on this project, you will hear these feelings.

I think your car is top notch David. I know Cam, and I know his craftmanship. There is nothing to feel bad about the conversion, but my original post was just about the current power production. Setting the inherent flaws of the rotary engine aside, Cam built your car to last. That is a nice warm fuzzy to sleep with every night, isn't it?

I honestly think you should ditch the "factory" twins. If you want to go to a twin turbo setup, go with something creative. But don't let those be your bottleneck at this point in the game. I have always been a strong supporter of ditching those twins since you started your project.

rx7tt95

David, CLR Motorsports makes a nice twin setup which according to the owner provides a very smooth power curve without the large and sudden hit of a big single. He races a 20B in SCCA. Not sure if you've seen the images or not but here are a few:
http://photobucket.com/albums/v112/GT1-20b/

I would qualify his knowledge about the 20B as being far superior to Cam's. It'd be a big step naturally, but when you're really ready to release the power (and you will!), contact CLR. They're in Miami. My engine is there right now being redone to his specs. He also installs 20B's into FD's without moving the steering rack and utilizing the stock subframe.

David Hayes

iTrader: (6)

I really don't mean to be defensive and I appreciate the interest in the project. At times, though, it just seems to be more effort and problems to post info than it is worth. Having said that, I'm interested in cointinuing the dialogue.

You have always been a big proponent in dumping the twins. Let me see what I can do with them first and I'll most likely be in touch for your "advice". Thanks!

David Hayes

iTrader: (6)

Thanks for the ino. I'll check him out.

WARTHOG

Just finished part one of my Turbo cooling mod. Intake 34c @ 7200 revs 0.95 bar of boost, 362.2 fwbhp -- 301.8 rwbhp @ 300ft/lbs. We could have made 400bhp but my standed clutch started slipping. Will post update when i have finished installing another small charge cooler using air-con gas to cool the water in the charge cooler before it goes into the main charge cooler. On the 12 runs the charge cooler stayed cold, result.

HDP

iTrader: (2)

Not trying to be rude, but what does this have to do with David's 20B topic? This is cool and interesting, but I think it belongs in it's own thread.

Fatman0203

Im guessing its water cooled?! ^

WARTHOG

Sorry posted in the wrong thread my mistake--and yes it is water cooled.

SPOautos

Not that I'm saying anything is wrong with your results but that info they gave you about the hp and tq is not right.......

Its impossible that your making 365ft lbs thru the entire rpm range with only 385rwhp. If you were making 365rwtq at say 7000rpms you'd be making 486rwhp at 7000rpms. Its a math formula, tq x rpm / 5252 = hp. If you were making 365rwtq on a dyno then its started dropping off at about 5500rpms and kept dropping a lot all the way to redline since you were only making 385rwhp. If you had 385rwhp at say 7500rpms then your tq at 7500rpms was only about 270rwtq.

Herblenny

iTrader: (13)

I've have to agree.. i havent acturally seen his car but my conversation that I had with David, he seems to know his stuff. Very Very helpful regarding my 20B swap.

David Hayes

iTrader: (6)

Whenever I receive the dyno file, I'll post it for you. My point was that the torque on a 20B comes on and is available much sooner than a 13B and the torque curve is basically flat thru the entire band. As I recall with my 13B, torque builds and peaks at about 4,500 and then starts to drop off. Yes, there is some drop off at the end of the 20B torque cureve, but nothing like the 13B..

SPOautos

I just heard thru the grape vine that Cam's dyno was all out of calibration anyway due to the hurricanes and it getting flooded out. Supposedly it was reading low....dont know if it still is or not......just thought I'd pass that info along since you MIGHT actually be making more power than what the dyno is saying.

Just something I heard thru the grapevine, I have no idea if its really true or not.....maybe check with Cam and see.

PalmTreeDoc

I'm back from my trip and came home a little under the weather. David, I'll try to get the DVD done by the end of the week.

Doug

speedracer2235

Hey David, I can't wait to see your results. Me and 20B10AE have been tuning his motor for awhile now. I just want to see where you end up so I'll have a good guage of what to look for with his car.