Don't want to de-rail here too much, but to be clear; Dan@519... are you talking about the TU5J4 and JP4? If you are, then I'd agree that most people seem to hit the wall at about 200bhp, but my top spec engines are genuinely getting over 220bhp and 150lbft, on our calibrated and DIN corrected engine dyno and without having to rev that hard, Dave's shown above (the engine that Will DC ran this year) is not my latest spec (last rebuilt in 2010) and was making about 215bhp@8250rpm. Earlier this year my best one so far showed 234bhp@8400rpm and 157lbft at 6500rpm (oversize 1600). I know as well as anyone that there's alot of bull in this business, but there is none in what I've written here and I hope I've misunderstood you.
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Price of a basic race spec 1*2
- Thread starter Tomshep86
- Start date
Yes if you both have the same power output anyway more or less, then one of you having closer to that peak power figure for longer in the range (ie a better spread of torque) will definately help.
Torque means you can develop power at lower rpm. Making an engine breathe better without attention to the effects of pulse tuning, will give you an engine that needs to rev to make power. Make an engine breathe well, with effective pulse tuning and a good burn, you'll get good power at lower rpm. Upside is reliable and highly effective engines, particularly on OE ratios, downside is people that don't know how it's done, won't believe it.
Not one of my customers to my knowledge has bought one of my engines on a power claim, they've all come to me based on the performance of the engines that they've seen and until recently, I didn't publish any figures for the top spec engines, because the rolling road data I had in the past was so variable, as rolling roads tend to be. Using an engine dyno to develop then engines and the work I've been doing with John Read (JRE racing engines, people in rallying will be aware of who that is), has moved my game on massively since 2010, when Will DC's engine was built. It's also given me alot more confidence in the recorded figures and pride has eventually forced me to publish some of them. I have some pretty good yardsticks to go by on the dyno we use, from some of the best 4 cylinder engine builders in the country. I would absolutely not publish any figures that I didn't have total confidence were accurate.
Last weekend I rolling roaded a 1600 TU I built for a rally car over in Ireland. It showed 164lbft on a dyno dynamics rolling road. I know that's not accurate and a good chunk more than we saw on the dyno, but how many people will swear blind that DD rollers are accurate or low reading?!
Not one of my customers to my knowledge has bought one of my engines on a power claim, they've all come to me based on the performance of the engines that they've seen and until recently, I didn't publish any figures for the top spec engines, because the rolling road data I had in the past was so variable, as rolling roads tend to be. Using an engine dyno to develop then engines and the work I've been doing with John Read (JRE racing engines, people in rallying will be aware of who that is), has moved my game on massively since 2010, when Will DC's engine was built. It's also given me alot more confidence in the recorded figures and pride has eventually forced me to publish some of them. I have some pretty good yardsticks to go by on the dyno we use, from some of the best 4 cylinder engine builders in the country. I would absolutely not publish any figures that I didn't have total confidence were accurate.
Last weekend I rolling roaded a 1600 TU I built for a rally car over in Ireland. It showed 164lbft on a dyno dynamics rolling road. I know that's not accurate and a good chunk more than we saw on the dyno, but how many people will swear blind that DD rollers are accurate or low reading?!
I'm sure dan isn't casting doubt over that, merely questioning if they would make the same power on the rollers he is used to using that's all. No big deal and I'm sure he is not questioning they perform.
I'm sure Sandys customers are more bothered about winning races than rolling road days anyway, and clearly his engines do that very well.
Sir_Dave
ClioSport Trader
Madness isn't it. To be honest, since the day i passed my test at 17 (im now 30) i have been in awe of Sandy's work with Pug engines (& Colin Satchell's work with chassis' development) and love reading about their latest developments and projects - still pushing the boundaries of vehicle designs that are pushing over 20 years old!! So my honest opinion is that someone with this level of knowledge should be welcomed to the CS forum with open arms, not belittled. At the end of the day, he's probably got more engine designing/building knowledge in his left testicle than 99% of this forum put together, so if he's doing an F4R, that is probably good for us.
With regards to the 'rolling road' power:
I read that as Sandy saying that on a DD rolling road (like RST's, or SRR) that most people on here say UNDER read, one of his engines produced considerably OVER what he was expecting compared to the engine dyno that he usually uses. As such, i would assume that when an engine produces 220bhp on his/JRE's engine dyno that is what he considers the 'real' figure, with the pub talk figure on a DD rolling road and/or similar potentially being substantially higher, as in the case of the 164lbft.
Dave, agreed he clearly stated it made even more power on a dd than at jre.
As per my post to Daniel though, I don't say where sandy is being put down or belittled, dan@519 is perfectly welcome to be slightly skeptical on the exact figure it would make on the dyno'd dan is used to using.
I don't doubt sandy's expertise with the pug engines in particular, and im sure no one else in here does either, as I said further back on this thread I'm positive if I tried to build an engine to the same headline spec (ie similar main components like cr and similar cam duration and profile etc) I'd expect to make a minimum of 10bhp less than he does as the devil is in the details and those details like manifold primary and secondary lengths and exact port sizing and cam timing etc come ONLY with lots of trial and error experimentation on one specific engine.
As per my post to Daniel though, I don't say where sandy is being put down or belittled, dan@519 is perfectly welcome to be slightly skeptical on the exact figure it would make on the dyno'd dan is used to using.
I don't doubt sandy's expertise with the pug engines in particular, and im sure no one else in here does either, as I said further back on this thread I'm positive if I tried to build an engine to the same headline spec (ie similar main components like cr and similar cam duration and profile etc) I'd expect to make a minimum of 10bhp less than he does as the devil is in the details and those details like manifold primary and secondary lengths and exact port sizing and cam timing etc come ONLY with lots of trial and error experimentation on one specific engine.
didn't mean to cause such a defensive response. For the record, engines I've built have made figures I didn't/don't believe either. Still front runners
I don't rate DD rollers fully, it's about trusting thre operator more than anything. They're exceptionally easy to fudge or just use the wrong way. I trust SRR for instance, but as an example of someone near you, Alan Jeffreys results are just funny.
nope, not in the slightest. I think they're the best they could be. Just messes with logic a little that one mans best is so much better than everyone else that has ever tried, including some exceptional engineers/engine builders
This has gone way off topic and I'm probably best advised to leave it as it was, but I think you've missed the major point here Dan. Chip says he'd hope to get close to what one of my engine with the same components; well there is most of the difference, you can't buy most of the components I use. I have developed and designed them myself; rods, pistons, cams, valves along with the hugely critical pipe tuning inlet/exhaust designs and of course the heads, which are entirely my own work. The component differences are generally small, but all add up and the pipe tuning/headwork make a vast difference; there are numerous examples of TU5J4/JP4 engines gaining 10-15lbft across the range from typical off the shelf DTH bodies to our designs and the same holds true with higher spec builds. Couple all of that with the improvements that come from the loop of setting up and mapping the engines myself (my main work is specialised mapping for other race engine builders) and i'm afraid the package difference is big!
I have to say I am a bit intrigued to know who you're exampling as "some exceptional engineers/engine builders". I have a feeling we might have quite different views on that as well.
I have to say I am a bit intrigued to know who you're exampling as "some exceptional engineers/engine builders". I have a feeling we might have quite different views on that as well.
