Mi16 Rolling Road Results

[SweetBadger 91]

Got my car on the rollers at Race Power Motorsport in Kent for a check up before a track evening at Silverstone this evening and it only made 154 BHP and 125.5 lbft. Bit dissapointed seeing as it's got a Catcams 4900526 inlet camshaft and has been fairly recently rebuilt...

 

The guys were helpful, seemed like they knew their stuff and reckoned that the AFR was spot on apart from right at the top end where it richened up a bit.

 

It's running standard 3 row management so there's not much to tweak - it doesn't look like there's any more power to come.

 

 

Oh well, the car's quick and at least I know that it's not running lean so I can take it back on track with peace of mind.

[Anthony 1,000]

Is the cam timed in properly? From memory, it's miles out on a #2 pulley...

[SweetBadger 91]

Is the cam timed in properly? From memory, it's miles out on a #2 pulley...

 

Yep it's running #4 pulley on the inlet and #2 pulley on the exhaust.

Edited July 17, 2008 by SweetBadger

[Tom Fenton 1,524]

Is that 154BHP at the wheels? If so then it is a good power reading when translated back to the fly.

[Baz 421]

That is surprisingly low then really given the spec! Wonder why!

 

I think there's a couple of guys from BigPower.co.uk at Silverstone tonight too, good bunch. There'll also (hopefully) be a portuguese guy there with a 205Mi on Carbs, the clutch just let go on the dyno setting up the carbs but hopefully he'll be sorted again by this evening! (Thanks to me!!)

[welshpug 1,621]

definitely something not quite right, timing belt tension and the position of the 2 tensioning pulleys can have a great effect on them, my STD 2.0 is running 160 ATF, it was running 143 before a belt change.

[SweetBadger 91]

I'd be very happy if that was at the wheels, but it's the flywheel figure...

 

The first run was even lower at which point I was bloody gutted but then we realised that the throttle wasn't fully open!

 

3 runs gave exactly the same curve and power figure as the one attached... Don't know why it's so low, would have expected at least more than the standard engine's quoted at but it's making less! Wonder if their rollers were reading a bit pessimistically.

 

 

I'll keep my eye out for the carbed MI tonight and see if I can keep up with him on the straights.

[VisaGTi16v 1]

Bear in mind that most rolling roads overread so you can ignore a lot of the silly figures you see on forums, it may be that where you went underreads a bit. Also about 99% of standard Mi16's made nowhere near 160/133 just like no 8v's made their claimed figure but it does still sound a little bit low. I had mine done at Sanspeed in Croydon which amongst SE sprint circles is considered fairly accurate and gives lower figures than a lot of places. Mine came out at 168/136 with a flowed and ported head, piper cams, different exhaust and filter. My friends Xsara VTS also came out at 168bhp with a decat, exhaust, fuel pressure changed (gained 8bhp??) so it sounds in the right ball park.

[nick 3]

Isn't the VTS 167bhp like a gti-6?

 

Nick

[SweetBadger 91]

I suppose if I'm happy with the way it goes that's the main thing, but the nice crisp piece of paper with a big power figure on it would have been the icing on the cake.

 

I had no problem keeping up with a cammed up stripped out MI on the straight last time I was at bedford autidrome, infact if anything I was a little quicker so it's obviously not that bad an engine... Or at least that's what Im' going to keep telling myself!

[taylorspug 7]

If it goes well enough on the road and is running right, i say just forget the piece of paper and enjoy it!

[VisaGTi16v 1]

Nick: Yes it is but thats my point, like with the mi16, 8v 205's etc, they never make book figures.

[Miles 331 1 Cars]

Might be worth trying one of Peter T's chip's as that will be limiting thing's slightly,

[SweetBadger 91]

Might be worth trying one of Peter T's chip's as that will be limiting thing's slightly,

 

I've tried one of petert's chips in fact we did a side by side comparison on the rollers and like peter says there's no real power increase just the extra 400rpm or so. Would have been nice on track actually as I ended up hitting the revlimiter way too often! Problem is I can't get it to idle properly with the performance chip no - matter how much we played with the co pot it ran really lean on idle.

 

Had a great time at Silverstone, the GP course is pretty challenging could have done with a bit more track time to get to grips with it. My mate was on his first track day so I was s*itting myself for his first few laps! We got some free instruction and it was all a lot smoother after that.

 

Baz - was the MI16 on carbs a stripped out black one on 1.6 pepperpots? Definetly sounded like an MI... Didn't get the chance to say hello but got behind it on a few straights and had no problem keeping up with it.

[James_m 0]

Was it much quicker with the catcam inlet compared to standard? Maybe something to do with that is not working efficiently like cam timing not being optimal?

These engines do seem to be very sensitive to timing, as Welshpug said even timing belt tension can have an effect.

My own Mi16 feels quicker when the timing belt is over tight, which unfortunatley leads to whining....

[PVFCpug 6]

Here's mine afer a complete rebuild at DES, carbs balanced and tuned by Hi Tech Motors in Walsall.

 

 

Needless to say I am well happy. Previous engine blew at Oulton and that used to put out 211BHP. This one has only run 1200 mile so could well loosen up more yet. Its an alloy MI with Twin 45 Webers, and a Cat Cam 283 set-up with Verniers. DES stainless exhaust.

 

First track day coming soon with this engine and canot wait. Got a lovely kick at about 4K, and now using an Omex rev limiter. One thing that did scare the s*it out of me was appreciating how much out the Pug rev counter is out by. Set the rev limiter to 7500 and the rev counter on the dash reads just over 6K, makes me realise how much we were over revving the previous engine (foolishly without Re Limiter)

[Daz_C 8 1 Cars]

^^^

Good results, I'm presuming you've had alot of other engine work done to get those kind of figures other than just a Catcam and carbs ?

[PVFCpug 6]

^^^

Good results, I'm presuming you've had alot of other engine work done to get those kind of figures other than just a Catcam and carbs ?

 

You'd be wrong. My previous engine (which blew) had a worked head, but this engine has a standard head with the cams. Standard pistons, liners, crank etc.

[Ethos 0]

208bhp, thats nuts.... can't imagine what that'd feel like in a 205. Is it very manageable? Got to be happy with that figure!

[SweetBadger 91]

Was it much quicker with the catcam inlet compared to standard? Maybe something to do with that is not working efficiently like cam timing not being optimal?

These engines do seem to be very sensitive to timing, as Welshpug said even timing belt tension can have an effect.

My own Mi16 feels quicker when the timing belt is over tight, which unfortunatley leads to whining....

 

I noticed a big difference when I fitted the catcam, but that was a while ago and with a different head so I haven't done a direct comparison between the standard cam and the catcam with the current head. The main difference when I fitted it was that it felt a little lazy lower down the rev range but had a nice surge around 4.5k pulling straight to the limiter whereas on the standard cam it felt like it was time to change gear at 6.5k.

 

The head on it at the mo has had the valves and seats done at qep (3 angle) so I'd be expecting it to flow a little better than a completely standard head... I also had a go at blending the seats into the port throat when it was last off, probably hasn't made much difference though.

 

I might have a play with the tensioners when I get time, I haven't moved the rear tensioner for ages as I found that you only need to loosen the front one to get the belt off an on. I seem to remember reading on here that you're supposed set the rear tensioner as far as it will go then take up any extra slack with the front one. Is that correct?

[SweetBadger 91]

You'd be wrong. My previous engine (which blew) had a worked head, but this engine has a standard head with the cams. Standard pistons, liners, crank etc.

 

Nice result, seems odd that peak power comes at 6300rpm though. Means you wont be giving it death to get the most out of it.

[PVFCpug 6]

Nice result, seems odd that peak power comes at 6300rpm though. Means you wont be giving it death to get the most out of it.

 

gives plenty of time for gear change after going past the peak tbh, pleased as previous engine was peaking at 7.5K for some reason. It does have a dry sump so not sure if less oil to slosh around in does it any good!

[Baz 421]

Baz - was the MI16 on carbs a stripped out black one on 1.6 pepperpots? Definetly sounded like an MI... Didn't get the chance to say hello but got behind it on a few straights and had no problem keeping up with it.

 

Sorry only just seen this, sounds like the one yes! Although i've only seen it on 1.9 rims. Jim his name is, portuguese guy.

[macaroni 17 1 Cars]

SB, I recently had my Matra Murena on the rollers at RacePower Motorsport and only got 105bhp at the fly. I was expecting over 130 at least and was pretty disappointed as it is a 2.2, with twin Dellorto 45s, Holbay Tornado cam and 4-1 manifold. The AFR was spot-on as was the timing. The compression was also reasonable, if not spectacular.

I would suggest their rollers read too low, but prior to my car was a short-circuit rwd Toyota Starlet that made 70bhp at the fly, which is spot on.

 

They are decent guys so I doubt any duplicity was going on, but quite a co-incidence, eh?

[monty69 6]

i wouldnt take these estimated flywheel figures seriously lads. Its the wheel hp thats important and more accurate