Jump to content
  • Welcome to 205GTIDrivers.com!

    Hello dear visitor! Feel free to browse but we invite you to register completely free of charge in order to enjoy the full functionality of the website.

Sign in to follow this  
Veero

Getting More Out Of An Mi16...

Recommended Posts

Jon_Bmw

I need to double check the exhaust size, thinking about it could be 2.5". The nasty backbox has an outwardly rolled tip which probably makes me think its bigger than it actually is.

 

It doesn't have the split down the middle as far as I'm aware. I took it to an exhaust specialist as it was touching on the bulkhead on hard engine movements(accel/lift off). He put a new section in to stop it touching, but knowing what I know now, i expect the easy option was taken and it doesn't have the split section. It also blows really badly at the manifold join as per usual. Pretty disapointing really. It wasn't maniflow in Salisbury by the way.

 

Peter, I believe it is yourself that has been recommended in this and other mi tuning threads. Can you supply the cam and chip? Or am I confusing you with someone else. :S

 

Any links to the specification of the inlet cam? Seeing as I want to change the timing belt soon, it seems the ideal time to change the cam.

Share this post


Link to post
Share on other sites
Jon_Bmw

Just found your website Peter. Having a read now. Are the prices enquiry only?

 

Perhaps you shoud have a link to the site in your signiture?

Share this post


Link to post
Share on other sites
Francesco
just waiting to see if it's possible to sort out this 306 24mm ARB to fit the 205 rear axle then the back end will be relatively sorted too.

 

You can also use a 106 GTi 24mm with 306 1.8 (or higher) end plates. Weld it to one end plate. A 106 GTi ARB is a couple of mm shorter as a 205 one, but it wil fit! You can also use the Saxo 16V ARB or a 106 Rallye 1.6 one, they are the same as the 106 GTi one.

Share this post


Link to post
Share on other sites
Jon_Bmw

These were the power graphs.

 

Run 3 we adjusted the AFM spring flap to get it to run closer to 12.5/13:1 as it was a bit lean on the previous two runs baring in mind it was around 14/14.5:1 under full load. It was moved 4 clicks, then knocked back 1 after run 3 as it lost a small amount of power at 7000rpm. Should be spot on now. :(

 

 

IMGP2403.jpg

 

IMGP2404.jpg

 

Obviously the lines don't cross at 5251rpm as the scales are different.

 

Does anyone else have any graphs to compare?

Share this post


Link to post
Share on other sites
VisaGTi16v

Two things intruige me about your graphs, how your bhp keeps going up to the limiter, mine tailed off at 6500 and went flat which I am thinking is the old injectors. Also the massive difference between wheel and flywheel figures. At sanspeed they gave mine 142 at the wheels and 166 at the flywheel, yours are 126 and 163?

 

Can anyone comment on this. Surely there should only be minor differences between cars using similar gearbox on a rolling road, wider tyres etc. I presumed most rolling roads used the same coast down technique to guesstimate the flywheel figure so how can the two comparisons above be so wildly different?

Share this post


Link to post
Share on other sites
Jon_Bmw

It is strange isn't it. If you look in this thread :

 

http://forum.205gtidrivers.com/index.php?showtopic=89445

 

which I revived earlier, I think the original poster may have taken his car to the same place. Out of interest, the bloke who does the rolling road is pretty sound, he is not into fudging figures. He says, and I agree with him, whats the point of making people think their car is better than what it actually is. A test at another rolling road would put him to shame otherwise. Obviously all machines are different, but i am pretty sure if you read into it the Dastek are supposed to be one of the best, and also the most expensive :(

 

I agree, the difference between the flywheel figure and wheel figure is drastic, don't forget it could be a whole host of things wrong with my car that would affect it, wheel bearings, tyre pressures etc. The thruth of the matter is that you will go faster with your ATW figure than me! As my car is wasting it somewhere!

 

On the same day, I went with a bunch of BMW guys, 2 325's were there, one sport, one touring. They put out when brand new 171bhp, both were the lower compression engines(there were two types) and it is often seen that they never make 171. usually about 165-168. Both made around about 163-164. Much to their annoyance, mine beat them both fractionally :)

 

The above, hopefully gives you an idea, that the rollers are pretty good, and that there could be something wrong with my car giving the high coast down losses.

 

I also found it interesting to see that it pulled hard up to the limiter. In an earlier post, I wrote about the fact the dyno print is exactly how it drives in real life. It needs a 7500rpm limiter for sure. Sadly I haven't been able to test it since adjusting the AFM as the roads were pitaful and soaking wet, something that doesn't agree with r888's. It should now have a marginally better pull in the mid range.

 

 

At the end of the day, once I start modifying it, it will be nice to go back to the same dyno and see what did what :D

Edited by Jon_Bmw

Share this post


Link to post
Share on other sites
24seven

if you can get round the management issues with a gti-6 manifold, then that's a good way to go, if not for the sound alone :D.

 

Your mates 1.8 must have a few choice parts underneath if it's giving your Mi a run for its money, even if it is stripped inside. that or your Mi is getting tired. My Mi is completly standard (apart from the car around it), and my 306 1.8 doesn't even compare. The 1.8 is only 112bhp standard according to the books, but apparently in reality they're a little more.

 

Have you considered a diffeernt engine altogether? with their age and issues, Mi16s are slowly retiring these days. There's a lot of tuning potential in the 1.8s which are becoming more popular, plus GTi-6 lumps have been done a few times, so the know-how is there.

Edited by 24Seven

Share this post


Link to post
Share on other sites
Veero
if you can get round the management issues with a gti-6 manifold, then that's a good way to go, if not for the sound alone :lol:.

Looks simple enough, got the gasket, all the take offs look easy enough, only thing is the throttle cable routing needs to be changed. Will hopefully fit it this week.

 

Your mates 1.8 must have a few choice parts underneath if it's giving your Mi a run for its money, even if it is stripped inside. that or your Mi is getting tired. My Mi is completly standard (apart from the car around it), and my 306 1.8 doesn't even compare. The 1.8 is only 112bhp standard according to the books, but apparently in reality they're a little more.

Nope, nothing special underneath. Just GTi6 manifolds, a very heavy foot, 1.6 box and perhaps less common sense than me. It was along roads he knew far better than me. My mi is no slouch though, feels like a good one compared to a few others I've driven. No reason it should be tired after the stuff that was replaced on it.

 

Have you considered a diffeernt engine altogether? with their age and issues, Mi16s are slowly retiring these days. There's a lot of tuning potential in the 1.8s which are becoming more popular, plus GTi-6 lumps have been done a few times, so the know-how is there.

Like I said to someone earlier the time and money I've spent on this engine I'm gonna get it working properly so the GTi6 is out of the question for a long time. After reading another thread about oil surge I'm half tempted to try the 8v crank and rods especially for the prices people are asking for complete 8v engines these days.

Share this post


Link to post
Share on other sites
Jon_Bmw

Bttt

Share this post


Link to post
Share on other sites
Jon_Bmw

Bump.

Share this post


Link to post
Share on other sites
Veero

Well I reckon I've settled on a reasonable course of action.

 

Immediate plans are to fit PAS to it so it's at least driveable round town (sterring is HEAVY with the eccentric top mounts), get it MOT'd and taxed. Once it's all road legal I will fit the 306 GTi6 inlet and TB. Then when funds permit I will get a PeterT inlet cam and chip to raise rev limit. Seems a fairly idiot proof way to squeeze a few more horses out without breaking the bank.

 

When I fit the cam I will pop the engine out and fit the XU10 sump and oil pump with the possibility of fitting a 1.9 8v crank and rods to help aleviate the oil starvation problem.

 

Sounds good to me. Thanks for the input.

 

Veero

Share this post


Link to post
Share on other sites
cherry_red

Really good set of photos on photo bucket. Great looking car thinking of sorting out my rear bumper, think its had a few bumps in the past as it seems to be sagging. Engine looks really tidy if mine looks half as good i'll be happy.

Share this post


Link to post
Share on other sites
Sign in to follow this  

×