4722 replies to this topic

[davemate]

the chap that made my system has also developed resonators, basically a slot in pipe that would allow you to remove one of the silencers, and put in a pipe that doubles back on its self, excelt the double back pipe is more open, so it extends the gas flow without restricting the flow too much. the other idea of the double end turn still stands, i just need to find out if something that would fit in my tail pipes would fit in yours, so to speak.

[Bargi]

If you're happy driving it for the road then perhaps some silencers? MatrinS got some made recently so he could go around Goodwood, think it's a mate of Frosty's who does a lot of work on these things.

[Korkey]

Siztenboots.........been away for a few days. My fault sorry................try this www.driveespana.com Korkey

[siztenboots]

Siztenboots.........been away for a few days.

My fault sorry................try this www.driveespana.com

Korkey

if we were to fly out 17th, flights ~£40 each way, and stay at the same place Hotel Abentofail, €71 a room for 2. The Guadix trackday is the 18th April.

[Korkey]

So as to not take over Nevs thread I will private mail you........when I know. Regards. Korkey.

[Nev]

Well, I bit the bullet yesterday and sent my spare throttle body off to be machined out to the max. Dan the engineer reckons he may be able to squeeze a 68mm to 70mm bore into the normally 52mm unit. I will fit the new TB, new bespoke airbox, 4 inch pipework & solid boost pipe in 1 job in a few weekends time once all the parts have arrived. I suspect this will require a mild remap though before I can boot it, mainly for the TB mod which will alter the flow characteristics at all RPMs. I will then bolt the clam down as hard as I can for some serious high speed testing. For the remap, it's tempting to raise the RPM limit to 8500 and maybe tweak the boost up a bit at the same time. This is easy to do and the engine is quite capable of it, but I fear for my gearbox and clutch which are both over the limit.

Edited by Nev, 15 November 2011 - 07:26 PM.

[Nev]

After 3250 miles of driving the car I have written up a 'warts and all' description of the driving experience HERE.

[luke.]

After 3250 miles of driving the car I have written up a 'warts and all' description of the driving experience HERE.

Nice little write up there Nev. And i know what you mean about the escort cossie. My old boss has one 410bhp and exactly the same off boost seemed tame. But in some way having it like that is better because when on boost it feels even more brutal

[spuk87]

Providing you are above 4000 revs, full boost power delivery can be resumed in approx 1/5th of a second by pressing the accelerator.

That's the bit that impresses me most, and it felt like it on the pax ride (granted it's not easy to feel turbo lag as a passenger). Never seemed laggy at all.

Edited by spuk87, 18 November 2011 - 06:01 PM.

[cs_]

Nev,

I'd just like to tell you how much I admire your work and your attitude! Yesterday I read your conclusions and I am very impressed. Funny, how my approach to the working process goes conform with yours.

Especially

10. Try and do you build somewhere you can just lock up and walk away from when pissed off.

cannot be emphasized too much. This is the most important part for me. Don't haste, don't hurry, don't get into someone else's garage where you have to get out again few days later. Take your time. And if you do not see the next step, take yourself time to think about it. Do something else. And some days later you get back to work with fresh ideas and less pain in your stomach. The effort will be big this way. With a minimum possibility of doing things wrong.

Congratulations! You've done a great job. I really enjoy reading your blog.

[Nev]

Nev,

I'd just like to tell you how much I admire your work and your attitude! Yesterday I read your conclusions and I am very impressed. Funny, how my approach to the working process goes conform with yours.

Especially

10. Try and do you build somewhere you can just lock up and walk away from when pissed off.

cannot be emphasized too much. This is the most important part for me. Don't haste, don't hurry, don't get into someone else's garage where you have to get out again few days later. Take your time. And if you do not see the next step, take yourself time to think about it. Do something else. And some days later you get back to work with fresh ideas and less pain in your stomach. The effort will be big this way. With a minimum possibility of doing things wrong.

Congratulations! You've done a great job. I really enjoy reading your blog.

Thanks for your comments Carsten.

Yes, taking your time and a relaxed approach lets you consider all options and do the right thing. I think it also saves money on wasted/wrong parts.

Let me know if you need any help/advice on anything, am always happy to help a serious 'moder'.

Edited by Nev, 20 November 2011 - 08:06 AM.

[cnrandall]

Good write up Nev and some great advice in there. Interesting how you prioritise a cam change. As you know, I'm still on stock cams but half looking to experiment with something different so would be interested to know your thoughts. Trouble is, nobody that I've come across has ever tried a change of cams in isolation, its always don't at the same time as head/valve work which makes it very hard to register what gains you're actually getting. What I would really like to do is spend a day at the dyno and test, say, three different profiles but to do that you need to find a cam company who actually cares about improving their product and not just selling their standard off the shelf stuff!

[slindborg]

Good write up Nev and some great advice in there. Interesting how you prioritise a cam change. As you know, I'm still on stock cams but half looking to experiment with something different so would be interested to know your thoughts. Trouble is, nobody that I've come across has ever tried a change of cams in isolation, its always don't at the same time as head/valve work which makes it very hard to register what gains you're actually getting. What I would really like to do is spend a day at the dyno and test, say, three different profiles but to do that you need to find a cam company who actually cares about improving their product and not just selling their standard off the shelf stuff!

that'll be CatCams or Newman then.

[Nev]

Good write up Nev and some great advice in there. Interesting how you prioritise a cam change. As you know, I'm still on stock cams but half looking to experiment with something different so would be interested to know your thoughts. Trouble is, nobody that I've come across has ever tried a change of cams in isolation, its always don't at the same time as head/valve work which makes it very hard to register what gains you're actually getting. What I would really like to do is spend a day at the dyno and test, say, three different profiles but to do that you need to find a cam company who actually cares about improving their product and not just selling their standard off the shelf stuff!

Indeed, cams are nearly always inserted as 1 of a whole batch of mods

I am fairly sure my cam duration has a lot to do with my sinusoidal torque graph, though this is a subjective view, based only on what I've read about moving the peak VE (ie torque) further down the rev range. As I am sure you know (but others might not), this promotes more power when at high RPM at the expense of loss of torque at low RPM. This is certainly a characteristic in Nipper now, hence my guess that the cams have been quite influential on the way that power is delivered. Having said that, Nipper does also have a heavily modified head/inlet including:

1. Solid lifters to give a more precise valve lift, particularily at very high revs. This also provides security from the terrible effects of valve float.
2. Aggresive ramp angles on the cam lobes to take advantage of the solid lifters, thus keeping the valves open for longer.
3. All ports carefully (and expensively!) opened out by an F1/Pro-drive supplying professional with 30+ years experience.
4. Waisted valve stems.
5. Cut down Audi valve guides.
6. Modified inlet plenum.

All these mods will have quite an effect too, so as you correctly point out, it hard to know which ones are affecting what characteristics. However, in conjunction they make a lot of power with just 1.35 Bar of boost. I think if I let CS map it to max boost (2.5 Bar) it would make 580 to 620 BHP, so these mods HAVE to be helping.

I have just replaced my Bailey dump valve with a second hand Forge unit this morning, so I am off for a test drive to see if it makes a difference. Also, Techieboy has kindly posted me his DB meter, so I am sticking that in the cabin so see what the sounds levels are.

I've also installed another mod but can't reveal it

Edited by Nev, 20 November 2011 - 10:25 AM.

[cnrandall]

I'm yet to see any valve float on the stock lifters. Usually I rev mine to 7500, sometimes I go as far as 7800 but I'm more worried about cavitation of the oil pump (if you log the pressure trace fast enough you can see this happening) than I am about the valve float. On our other race Europa we lost two followers when the driver buzzed it on a downshift but there isn't much accounting for that! I've done the manifold change in isolation and that's a BIG gain on high powered cars, like taking a cork out! When racing I always consider how cheap/quick it is to replace parts and I can get a brand new head complete from Vauxhall (less cams/followers) for very cheap money so my aim is to leave that alone as much as possible so if I overheat it I simply swap it our for new with no hassle. Cams have to come in/out when you change a head anyway so it has to be worth a look so long as I can stick to stock springs/followers.

[Nev]

Hmm, just got back from a little run. The Forge bypass vavle does seem to be working slightly better, maybe as it has a weaker spring in it. As I am only boosting my turbo to 1.35 Bar (less than a Stage 4 car !!), maybe it's just the weaker spring that is helping. However, the turbo is still stalling a bit, so maybe I will also plumb the Bailey back in as well and run 2 bypass valves. My other 'secret' mod works, hehe The car seems so settled and fine to drive now, it seems a shame (pointless?) to take the clam off and fit the new airbox and pipework, as this will only lead to more power and more violence. Matt's sound level meter registered 93 dB in the cabin (though I only reved it to around 6000 RPM) - this is great news. All I need to do now is arrange a drive by test.

Edited by Nev, 20 November 2011 - 11:52 AM.

[cnrandall]

Good news on the noise Nev :-) I'm doing an Easytrack day on the 30th at Silverstone GP... has to be a great chance to stretch her legs?!

[cnrandall]

Just looking on t'interweb cam options and stumbled across Nippers power graph on dyno-plot. Interesting to compare and contrast with mine http://www.dyno-plot...honda/index.htm Mine is running more boost and race fuel, Nipper has a turbo that flows more air in theory so that needs taking into consideration. On that run we only went to 7000rpm, but power reduces after then so mine would be loosing out anyway. Interestingly, mine makes a good amount more power low down, like 80bhp @ 4k but then Nipper holds out at the top end better. Peak torque is incredibly similar but obviously we are comparing these two cars on different dynos too.

[Nev]

Just looking on t'interweb cam options and stumbled across Nippers power graph on dyno-plot. Interesting to compare and contrast with mine http://www.dyno-plot...honda/index.htm

Mine is running more boost and race fuel, Nipper has a turbo that flows more air in theory so that needs taking into consideration. On that run we only went to 7000rpm, but power reduces after then so mine would be loosing out anyway. Interestingly, mine makes a good amount more power low down, like 80bhp @ 4k but then Nipper holds out at the top end better. Peak torque is incredibly similar but obviously we are comparing these two cars on different dynos too.

Bloody hell Chris, your turbo is spooling up 500 RPM earlier than mine - that is a lot. However, as you say I have a lot more boost available, not that my gearbox/clutch could take much more. I just had a look at the Sadev and Quiafe websites, they dont even make a FWD gearbox that can take 350 ft/lb, let alone 450. Pathetic.

I am working on some air-flow mods ATM (airbox, larger pipework, massive TB) - I think these will liberate quite a bit of power at the very top end, maybe 10 to 25 BHP.

Im bored, need another project now. I'd love to learn how to weld and make a single seater from scratch and put one of my engines in it - realistically though, it's not likely to happen as I dont have enough garage space.

Edited by Nev, 20 November 2011 - 03:22 PM.

[cnrandall]

It may well be that my boost control is that much better as we get great boost response regardless of absolute pressure... the same engine can be manipulated to do this http://www.dyno-plot...HofmannsTDI.htm I'll be interested to see what the airflow mods do. I'm on a stock TB but worse than that is there is a big shoulder on the joint between my chargecooler exit and the pipe the the TB and I keep thinking that's a bottleneck on mine. We must drag them both to the same dyno at some point, would be great to do an analysis of how they get their performance and where the gains are from.