3.9 RSR project --- my Carrera reborn

[911pcars]

Originally Posted by 911teo

Short trumpets give you more torque in the middle but sacrifice some top end power. Long trumpets do the opposite, favouring HP at the high end vs torque in the middle range.

Because the cams currently on the car give enough torque in the middle the long trumpets would be ok in the search of the extra power at the top end.

But we are talking about 3-4hp at the top at the most...

Generally accepted theory is that short intake tracts are best for high rpm power while long intake tracts produce more low end torque.

If you look at most manufacturer's variable length intake manifolds, two paths are available; a long and short path controlled by an ECU acting through a valve or set of valves to change the air intake path. The long path is the default path from idle up to a certain engine speed, load and other engine/vehicle factors; at which point a shorter path is presented to shorten the air flow path to the intake ports.

Sherwood

[911teo]

There you go... I had it backward.... Sorry

[911pcars]

No problem. I'll trade your faux paus for your "problem" car though.

Sherwood

[911GT2]

Hello Matteo

I know that this is kind of late to ask, but what color is your car?

Thanks in advance

Sergio

[barney911rs]

Sergio,

You seriously need to read this thread from the beginning. It's well worth it. All your questions will be answered.

[mpeastend]

911GT2: The color is several shades darker than Mexico Blue. It had to be darker because they couldn't match the powdercoat to the stock Mexico blue hue. Powdercoating was used on the chassis after it was baked, stripped, etc. due to it's durabilty & toughness. Instead of having the underbody darker than the sheetmetal they darkened the paint several shades to match. Just about everybody I know likes it the way it is. I personally have a mexico blue car which is a clone of Matteo's & am not fond of the color...it's a little too much like powder blue. Matteo's is really nice, sort of a lighter version of Audi's nogaro blue.

[911teo]

I just wanted to wrap up the thread with the final dyno numbers, set up and considerations...

I am super happy with Ninemeister and how the car has turned out. These guys are very meticolous, skillful and talented, but most of all they are enthusiasts.

I remember when after a track day at the local track to shake down the car there were 8 people working on my car (swapping front calipers, reconvert the RS- fan pulley to a dual-pulley solution and other minor changes) at gone 6pm so that I could get home at a decent time (I live 220 miles from their shop)....

Anyway the final numbers stack up like this (on the 9M dyno):

Power = 404.0HP @ 7,200 rpm
Torque = 452Nm @ 5,141 rpm

Bob Watson had dynoed the old 3.9L engine at "above 385hp".

The difference between the 2 powerplants is not so much the peak power but the eagerness of the 9M unit to get tto redline. In 1st, 2nd and 3rd is quite incredible.

Also (as you can see from the chart) the torque curve is quite flat, giving the engine a great elasticity, very useful for street driving.





Another area where I thought the car needed sorting was the geometry as I felt it was very nervous, especially on the road where the tarmac is not often smooth.

Well at first we threw away the Goodrich (I think the major culprits of the herratic behaviour of the car, understandable after having been on the car for 3 years) for some Toyo R888.

Then sorted some Toe and Camber issues at the rear.

This is what I am running now...




I have now ordered a set of the Zuffenhaus Fuchs in 17' and I am thinking of going down a size for the tyres.... 255s and 315s look cool, but I feel the car is over-tyred at 1,050kg (2,350lbs) when you think a GT3 comes with a 235-295 combo.

For once I think the car is now really sorted.

I am looking forward to falling in love with it again, to learning how to properly drive a 911 on the track again (after a sweet year with a mid-engine car, but that is another story), to driving to the pub on a sunny Sunday afternoon...

Thanks to ya'll for the support and encuragement.

I will make sure to keep you posted with impressions and what was worth it, what was overkill, what was a miss etc... but I feel I need to get some proper miles in it before I can attempt a serious analysis.

Ciao for now

Matteo

[CBRacerX]

Cheers Matteo - thanks for the update! Enjoy the "new" version and those B roads

[mjshira]

Happy for you mate

[johndglynn]

Sounds good mate. You could take a run up to Centre of Gravity some time and have those alignment settings double checked to be sure, his set up there is outstanding.

Am trying to clear some space to come pax with you next Wednesday - looking forward to seeing how she goes!

[davisriley]

Glad to hear it's done. Enjoy it in good health. Those are some very good numbers.

[911-32]

Yep - Another one looking forward to a ride on Wednesday.

[lateapex911]

Thanks for the update. I'll have to get my iPhone out and do the conversions to lb feet! How do you like the R888s? All my Spec Miata friends are rather hateful when they speak of them compared to the older version.

I wonder if your desire to go to a smaller tire is borne out of a compound issue? Not a soft enough compound for the weight? For track use, I imagine a tire like a Hoosier A or R compound, or a Hankook Ventus in a C51 or 71 compound would do the trick. Driving around town though on R compounds when cold is NOT advisable. The "A's" are better, but they still like a bit of heat. LOL.

Were you able to drive the car with the new tires but old alignment? Curious if the erratic behavior was alignment related or not. I see some changes at the rear, but I'm not sure what they actually were. Did the toe go from out to in on the rear? (I'm not familiar with, and can't read the little print on that display)

In the end, finding a great dual purpose tire is very hard.

Thanks for keeping the conversation going here, and glad you're hammering it a bit!

[CBRacerX]

Originally Posted by lateapex911

Thanks for the update. I'll have to get my iPhone out and do the conversions to lb feet! How do you like the R888s? all my Spec Miata friends are rather hateful when they speak of them compared to the older version.

I wonder if your desire to go to a smaller tire is borne out a compound issue? Not a soft enough compound for the weight? For track use, I imagine a tire like a Hoosier A or R compound, or a Hankook Ventus in a C51 or 71 compound would do the trick. Driving around town though on R compounds when cold is NOT advisable. LOL.

Were you abloe to drive the car with the new tires but old alignment? Curious if the erratic behavior was alignment related or not. I see some changes at the rear, but I'm not sure what they actuall were. Did the toe go from out to in on the rear? (I'm not familiar and can't read the little print on that display)

In the end, finding a great dual purpose tire is very hard.

Thanks for keeping the conversation going here, and glad you're hammering it a bit!

The rear now has much less toe in. This is a fairly common setup for an early (-89) suspension with wide tires. The rear will create toe in anyway as the suspension is compressed, so you do not need that much, too much will create a lot of drag!

[911teo]

Originally Posted by lateapex911

Thanks for the update. I'll have to get my iPhone out and do the conversions to lb feet! How do you like the R888s? All my Spec Miata friends are rather hateful when they speak of them compared to the older version.

I wonder if your desire to go to a smaller tire is borne out of a compound issue? Not a soft enough compound for the weight? For track use, I imagine a tire like a Hoosier A or R compound, or a Hankook Ventus in a C51 or 71 compound would do the trick. Driving around town though on R compounds when cold is NOT advisable. The "A's" are better, but they still like a bit of heat. LOL.

Given the sizes there is little choice here. Either R888 or V70s. Hoosiers are not road legal here in the UK.
I am waiting for the second set of wheels to mount the Hoosiers on.

Originally Posted by lateapex911

Were you able to drive the car with the new tires but old alignment? Curious if the erratic behavior was alignment related or not. I see some changes at the rear, but I'm not sure what they actually were. Did the toe go from out to in on the rear? (I'm not familiar with, and can't read the little print on that display)

In the end, finding a great dual purpose tire is very hard.

The herratic behaviour of the car was definetly due to the tyres. I mounted the Toyos and the car magically started "behaving" even with the old set up.

What CBRacerX said about the toe.

Originally Posted by lateapex911

Thanks for keeping the conversation going here, and glad you're hammering it a bit!

Next Wed I am booked (with a lot of UK 911 nuts) at Snetterton for the 1st track day since the car was 100% sorted. Cant wait!

[Bill Verburg]

Very nice Matteo!!

Can you review the differences in run 002 vs 053&6?

[911teo]

Yes. I am away for a couple of days. I will elaborate when I get back....

[Reaper930]

Matteo,

Congratulations my friend on your achievements, stand-up "eye-on-the-prize" attitude and perseverance to see out the true car through all the trials. I wish you nothing but the best, and I'm truly happy to see you reaching this point.

Enjoy in good health brother!

[MrPerkles]

Teo
knew it would come good in the end ,persistence was the key ,anyhow any chance of some on board video from next week as sadly I cant make it

Cheers Andy

[Randy W]

Congrats!