Cams

[2Damnsly Andy]

TBH if the car made 185 on X cams or 190 on Y cams there would be such little differecne in the performance it would be unmeasurable on the road. What are the supposed power differences between the 438's and the GT cams if any?

 

[Silent_Scone]

The same difference that's measurable between 428s and 421s most likely. You're looking at 5 or so BHP if mapped well, and you're bang on. GT's would be fine for a road going car, you're never really going to notice the difference.

 

[Chip-mk1]

TBH if the car made 185 on X cams or 190 on Y cams there would be such little differecne in the performance it would be unmeasurable on the road. What are the supposed power differences between the 438's and the GT cams if any?

TBH normally the 3-4/blft you gain by using a 5bhp hotter cam at the top end is accompanied by a bigger loss at the bottom end.
There really isnt one best answer to what cam is the best, peak figures are only half the story anyway.

Bottom line is the standard 172 cams are too mild for sprited driving, so pretty much any aftermarket cam is worth doing.

 

[2Damnsly Andy]

And the 197 cams, where do they fit into all this?

 

[Pedro19]

And the 197 cams, where do they fit into all this?

Slap bang in the middle for performance but a lot cheaper than aftermarket cams IIRC.

 

[Silent_Scone]

If you can pick them up cheap enough and you're due a cambelt change, I'd consider them. Seem to offer more peak power than the standard mk2 ones at a third of the price of after market ones

 

[Chip-mk1]

And the 197 cams, where do they fit into all this?

They are cheap upgrades, but bear in mind they are still a standard cam from another car so are compromised in terms of needing to meet emissions etc, so dont ever expect the performance of a set of 421s etc, although their road manners are very good if timed correctly (the 197 has more advance available than the 172, so the cams are optimised with that in mind)

 

[davo172]

Would be intresting to get these cars with different cams to run on same rollers,same day see how they compare as rob said

 

[Chip-mk1]

Would be intresting to get these cars with different cams to run on same rollers,same day see how they compare as rob said

Trouble is the standard engines vary so wildly you'd not be learning about just the cams.

Would you like it if I could find you a cam that on the standard inlet with just a filter and exhaust could give 165lbft and 182bhp for example?
Cause thats what millerins did on standard, I bet a lot of 172s wouldnt do that even with the 197 cams.

 

[dmallett]

The same difference that's measurable between 428s and 421s most likely. You're looking at 5 or so BHP if mapped well, and you're bang on. GT's would be fine for a road going car, you're never really going to notice the difference.

This is spot on imo.

I had GT cams, after mapping and ARP bolts it made the car a lot more usable on the road and track.

As Chip said any cams are worth the upgrade.

 

[Wick]

Would be intresting to get these cars with different cams to run on same rollers,same day see how they compare as rob said

No good really. You need one car on indy rollers.

Standard cams
Belt change and 197 cams
Belt change and GT cams
Belt change and CatCams (in various profiles)

The list is endless. But unless someone has the time and money to do all of that in the same temp conditions, you're never going to get an accurate comparison.

The other option is to take 10 cars running 438's and take an average power gain from them to give a ballpark. Again, still not ideal.

 

[Chip-mk1]

No good really. You need one car on indy rollers.

Standard cams
Belt change and 197 cams
Belt change and GT cams
Belt change and CatCams (in various profiles)

The list is endless. But unless someone has the time and money to do all of that in the same temp conditions, you're never going to get an accurate comparison.

The other option is to take 10 cars running 438's and take an average power gain from them to give a ballpark. Again, still not ideal.

Exactly the problem is who would fund it considering there is no financial gain from doing so.

I did a similar thing with camshaft swaps and timing for Total Vauxhall magazine, but these days there is a lot less money in the mags for stuff like that so I doubt it would happen in the french mag unless a tuner decided to fund it, and I dont really see the advertising would really be worth it TBH

 

[sprintcup]

stick them on Pauls dyno and see how they go

I thought TDF's and RS Tunings RR were 2 you could trust as most have said on this forum, I did question mine but Matt said that's what it made but I got no before reading, I'm not looking to argue about this just stating what I found and I've gained 23bhp between the 2 RR,s with not to many mods tbh, it does however feel better low down but I'm still on standard cams.

Regards Russ...........

 

[Fred@BTM]

to be honest any dyno is going to have some form of inaccuracy, makes no odds luckily in this case jonny has "PROVEN" the gains in the real world!

take my car, STANDARD engine = 190bhp on TDF dyno - do i believe it? in the pub yes, in the real world no, is it quick? yes = happy

 

[Dan519]

I thought TDF's and RS Tunings RR were 2 you could trust as most have said on this forum, I did question mine but Matt said that's what it made but I got no before reading, I'm not looking to argue about this just stating what I found and I've gained 23bhp between the 2 RR,s with not to many mods tbh, it does however feel better low down but I'm still on standard cams.

Regards Russ...........

tdf reads 5% above any other dyno used regularly on here. ive said this for a long time

 

[Chris205]

tdf reads 5% above any other dyno used regularly on here. ive said this for a long time

Dont they not use the same dyno as k-tec? Meaning in theory k-tecs rollers will read 5% over as well?

 

[mitch1503]

Dont they not use the same dyno as k-tec? Meaning in theory k-tecs rollers will read 5% over as well?

yes same rollers but nope on 5% as its all on how the rollers are set up and iirc Laines cup made within 2ish bhp on SRR to what he did at K-tec

 

[Dan519]

Dont they not use the same dyno as k-tec? Meaning in theory k-tecs rollers will read 5% over as well?

not necessarily true at all. for a start superflow say losses should be measured by run down, this is how their dyno is meant to be used. However its not how it is used at tdf. my benchmark is SRR and ive had a number of cars make within 2bhp between ktec and SRR. I dont like how DD rollers do losses, but they are at least intended to be used this way

 

[Laine_16v]

186bhp / 157 ft lb at SRR
183bhp / 163 ft lb at Ktec

Standard spec, the SRR was a hot summers day and the Ktec was quite a chilly day.

 

[JohnnyE]

Russ I'm up at Wigan on Sunday for the sprint you can have a go of my car and see what you think

 

[rob_sri]

meh, like fred says = happy ! feels like 195ish bhp to my foot!! love it! will get a dynodynamics print too this sunday and upload

 

[Fred@BTM]

But saying that Danny, TDF's dyno regularly sees accurate figures when compared to HKS' engine dyno next door

but we can go round in circles on this forever, SRR years back reckoned my 1.2 16V had 90bhp, everywhere else was nearer 82bhp

swings and roundabouts, it'll go on and on and on for years all this dyno rubbish, you can't win races stood still afterall

 

[Dan519]

this is true. mostly sales pitch bullshit anyway. Its bewildering what people will believe sometimes, but show them shiny stuff and use big words and they part with huge amounts of money. dynos are 90% for mapping.

 

[Silent_Scone]

If you want proper white lies get a Dastek.

 

[sprintcup]

I think the problem is to use the same RR to compare mods, you need to know if something has gained or not, as I've said my gains are against times I've set last year but have to add to
add the suspension mods to this, I've averaged 3-410th's at events from last year but I am getting older and slower, wish I'd stuck to my guns and just gone with the suspension mods.
The drive by wire TB was getting worse and I went for the ECU and single Tb to get rid of the crap response, I'll be driving it next year as is and saving for the diff and box.
It'll be good to have a drive of yours John, pity I couldn't do Aintree as you got 2 fun runs so we could have swapped cars for the last run, see you at 3 Sisters if you can make it.


Regards Russ........

 

[Russ_16v]

to be honest any dyno is going to have some form of inaccuracy, makes no odds luckily in this case jonny has "PROVEN" the gains in the real world!

take my car, STANDARD engine = 190bhp on TDF dyno - do i believe it? in the pub yes, in the real world no, is it quick? yes = happy

Dynacups got voodoo in it iirc

 

[mitch1503]

Trouble is the standard engines vary so wildly you'd not be learning about just the cams.

Would you like it if I could find you a cam that on the standard inlet with just a filter and exhaust could give 165lbft and 182bhp for example?
Cause thats what millerins did on standard, I bet a lot of 172s wouldnt do that even with the 197 cams.

pretty much what mine did although i think mine was 160lbft

 

[Dan519]

If you want proper white lies get a Dastek.

oh good god, im sure they go by american standards

im fed up of all the differences and uncertainty to be honest, so i'm refurbishing an old clayton and fitting a full new digital aquisition system. noone to blame or question but myself then.

 

[shiftspark]

I think the problem is to use the same RR to compare mods, you need to know if something has gained or not, as I've said my gains are against times I've set last year but have to add to
add the suspension mods to this, I've averaged 3-410th's at events from last year but I am getting older and slower, wish I'd stuck to my guns and just gone with the suspension mods.
The drive by wire TB was getting worse and I went for the ECU and single Tb to get rid of the crap response, I'll be driving it next year as is and saving for the diff and box.
It'll be good to have a drive of yours John, pity I couldn't do Aintree as you got 2 fun runs so we could have swapped cars for the last run, see you at 3 Sisters if you can make it.


Regards Russ........

Bollox !!!

Russ I'm up at Wigan on Sunday for the sprint you can have a go of my car and see what you think

Cough, cough

 

[shiftspark]

Gripper with lower final drive and decent coilovers is all we need(ed)

 

[JohnnyE]

I have plans for next year i need to find another 2 sec's and no weightwatcher jokes boys:rasp:

 

[shiftspark]

quaife

 

[JohnnyE]

And that induction kit from Ktec 5bhp

 

[sprintcup]

Gripper with lower final drive and decent coilovers is all we need(ed)

What I said ages ago, how F***ing stupid are we then, still not sure about these Bilis and will have to lift it up and see how it goes, I'll take the ARB up to stiffest setting as I've noticed the near side rear spring has moved to a strange position on it's seat:S

 

[shiftspark]

Have you had the regs through Russ ?

 

[sprintcup]

Have you had the regs through Russ ?

Yes, they have only got 40 up to now and John said they are leaving options open untill Friday, I think as you know 60 is the min for them not to loose out.

 

[shiftspark]

There is 64 on mine I entered today.
You know me I am like a smoker , I just can't kick the habit.

 

[rob_sri]

And that induction kit from Ktec 5bhp

*sigh*

what is the difference bar say almost £120 lol?

 

[Chip-mk1]

186bhp / 157 ft lb at SRR
183bhp / 163 ft lb at Ktec

Standard spec, the SRR was a hot summers day and the Ktec was quite a chilly day.

Temperature shouldnt make a difference as the rollers have a formula built into them to bring the figures back to a baseline of 25 degrees anyway.

So if you run a 200bhp on a hot day it will measure 190 and then the dyno will add in an extra 10bhp to bring it back to be 200 and if you run it on a cold day it will make 210 but the dyno will knock 10 off before it gives you the figures to still be 200.

The problem is of course, if 2 different operators put the temperature probe in different places they will get different values.

I mapped a 1600 ford engine for a lad who was convinced it should do 175bhp because of what he had read on forums, it made 172 on dyno dynamics when I mapped it and there really was no more in it, no matter which way I went with the fueling and timing that was all it would do.
When he seemed unhappy with the figure, I moved the temperature probe to show him how easily I could make it do more power (it made just over 180bhp instead), and asked him which graph he would like, the bullshit one like everyone else has or the real one. He went for the real one, and when he drove it when it got off the rollers it was way quicker than he expected anyway.

Dynos are a tool used for tuning a car, but its only if they are operated in an identical manner and maintained to an identical calibration that they will give consistant and accurate results, different operation methods even on the same dyno on the same day will give different results. And thats before you allow for the fact that the "before" run may well not have been quite at full throttle, which IMHO looks to be the case with some of the rolling road printouts Ive seen on here where massive gains have been made without enough changes to make that realistic.

Even things like strapping the car down more loosely on the after run can make a difference.

Bottom line is that if the person operating the dyno wants two runs to read so that one is higher than the other, they WILL do, irrelevant of whether the car makes different power or not.

 

[Chip-mk1]

PS, this is what I mean about strapping the car so it climbs the front roller.

How's that for a power gain.

Thats 2 runs a minute apart, no changes to the car, just the straps being deliberately changed to show the effects.