Turbo still not finalised ?

[macspring]

The casting configuration on a k26/3071 hybrid is a T31 housing or similar with a round cutout to match the k26 flange. A T3 flange has a much larger opening allowing for improved airflow resulting in better scavenging from the combustion chamber. This in turn means more fresh air to burn the fuel creating a more complete burn less prone to knock.

Thanks JP.

Never knew this.

So a T3 Wagner exhaust manifold with either a 2871 ( .63 or .82 ? ), or a 3071 ( .63 or .82 ? ) might suit best ?

No comments regarding the suitability of DJ Jones spec of a CT357 ?

Thanks.

[A80Avant]

i think only DJones can say for that, but the car he is using it in is alaso very light, and setupwise very good, so it would bring the best out in any turbo

[Jamo]

Ct357 is silly money and K26 flange only a ct5658 from compturbo is better value

[A80Avant]

even though people are getting some good results with comp, i would still be too scared to try one...

[prj]

David, even a 3076/0.82 is good in the city, because you can get full boost in 1st gear.
If you want torque from 1500 rpm buy a V8.

You either get full boost by about 3200 rpm MAX in 3rd and use 2nd in city (and that will be only stock turbo, maybe K24-7400).
Or you get full boost by upto about 4200 rpm max in 3rd and use 1st in city.

So basically 3400 to 4200 you will be always using 1st gear if you want to move the car fast.

And in that range you have from Garrett Range:
2871/0.82
3071/0.82
3076/0.82

KKK Range:
K24-7200
K26/K27 #6

Holset:
HX 35 Super

You have a fully built engine. Fitting a tiny turbo on that is a huge waste if you ask me.
You have all the supporting mods to go balls out and fit a HX35 Super or 3076R, or if you would want to re-use a maximum number of your current parts, a K26/K27.
Regardless of which you fit, you won't be able to use 2nd gear in town anyway if you want to go fast suddenly (and that's the ONLY place where lag matters).

The big advantage of Holset and KKK turbos is that they are rebuildable and their parts very cheap.

The whole question is about gearing. That's why I think the RS2 turbo and 2871 are pretty much useless, as the way you drive with them does not really change.
Due to all the mapping I've done, I've driven so many different combinations now...

[macspring]

Dmitri,

At this stage you'll be getting sick of me, but I feel I am making progress on my ultimate choice of turbo for my requirements.

Couple of questions,


1. I appreciate 034 can type what they wish on their site, but this turbo is chaper than a 3071 on their site, and they "say" it spools quicker than a 3071 and with more power than a 3071 ? Too good to be true ?

http://www.034motorsport.com/turbochargers-and-accessories-precision-turbos-precision-cea-5557-turbo-billet-compressor-wheel-p-20077.html

2. While I know this is dearer than a GT3071, what do you think of this newer turbo ? Irespective of 034's comments.

http://www.034motorsport.com/turbochargers-and-accessories-garrett-gt-ball-bearing-turbos-garrett-gtx3071r-billet-wheel-turbo-p-21267.html

3. If money was not the overriding issue, and you were prepared to endure a bit of fitting grief, what would be your own first and second choice of turbos be for my application ?



I laughed at your accurate comment about the V8. Appropriately timed comment.

Thanks.

[Thuppu]

You have a fully built engine. Fitting a tiny turbo on that is a huge waste if you ask me.

Totally

[A80Avant]

David,
you have to keep in mind that all of us have different opinion on what a 'quick car' on the low revs should be like. Most of us who have had a full engine rebuild, and ported heads (besides our own to keep spending money on the car!!! ), have the same feedback, and that is: car feels light and fast off boost, sufficient to not need boost from 2500rpm.

This however is something that unless you experience yourself in someone's car, you wont know if it is what you want, or if it is more than that.

On prj's list of turbos, i will add the 3071 and 3076 with the 0.63ar which he always leaves out, as when you compare the KKK he puts up, they always have the #6 hotside which is more or less equivalent to that of the 0.62AR rather than 0.82AR. SO if using a garrett is what you want, then the smaller hotside will bring boost much faster and produce less hp than the 0.82AR equivalents at the top end, which is something you dont mind for either.

The GTX series as tested from a few people on non audi cars, yielded these results: Although wheels are billet, spool was excactly the same as their non billet counterparts, BUT on all occasions more hp was produced because they were larger turbos!. They concluded that from all combinations, the best was the 3076GTX with 0.63AR but that will allow for 500+hp from your car and potentially spool somewhere in the region of 3600-3800rpm on 3d gear. So if you were still keen on the 3071R size turbo to keep somewhere around the 400ish+ region, i suppose a GTX version should only yield more hp rather than better spool.

I must say your setup is pretty good already, and i wont say comments like Dmitri's : to put a small turbo on that is a waste of time. In that case, AndyP has wasted all his time and money putting a GT3071R with 0.63AR on his stroker!!!!

It really depends on what YOU want. No matter how many responces you get, its your final choise and noone elses.

Good luck!!!

[prj]

On prj's list of turbos, i will add the 3071 and 3076 with the 0.63ar which he always leaves out, as when you compare the KKK he puts up, they always have the #6 hotside which is more or less equivalent to that of the 0.62AR rather than 0.82AR.

Except K26/K27 with #6 does not surge and makes roughly the same power as 3076/0.82 with roughly the same spool, but slower ramp speed. Don't forget that K26/K27 hybrids nowadays use modern wheels.

Also, GTX3076 will have full boost by about 4300, and 0.63 hotside is way too small for it, you won't be able to take the advantage of the fact it pushes more air at all.

[A80Avant]

have you tested that yet, or is it assumptions only on the GTX series? Cause i have read tests on those turbos to state what i am saying.

K26/27 on a #6 will make the same as a GT3076R 0.82? can you also show this with any dyno results? on the same spec engine?

I made roughly 490 (if im strict) and 500 if im casual on the 0.82AR 3076. Does the K26/27 make that power? (and did that on a non ported head, only wagner IM and SQ EM).

Ill tell you what, i am happy to test any K26/27 turbo engined I5 here in the UK that you have tuned, with the perfomance box, on any road and compare speed times as well as use the same excact excell sheet i have used on my runs. And if any of these owners are happy to come at the north east, ill be happy to use the excact same road.

I think the K26/27 turbo is inferior to the 3076 0.82AR. I think it is more equal to the 0.63AR equivalent.

Epic's car made 480ish hp at MRC with motronic tune (3076R 0.82) with more or less similar setup with mine (but dont remember if the head was also ported).

[A80Avant]

here is the link with quite comprehensive testing on the GTX series.

http://forums.nasioc.com/forums/show...2110277&page=4


a small quote from that thread:

We always tell customers, buy the turbo that fits your needs and nothing bigger as it will be slower responding for no reason. In the case of the GTX3071r, I see no reason to sell these as it should spool the same and will make less power than the GTX3076. What I would say is this customer should consider buying the GT3076r as it flows about the same and costs much less. Keep in mind I am guessing that the GTX3071 spools just like a GT3071 because of my results I found with the GT3076/GTX3076 comparison, and my GT3071/GT3076 comparison all using the same turbine wheel.

[prj]

have you tested that yet, or is it assumptions only on the GTX series? Cause i have read tests on those turbos to state what i am saying.

I have experience mapping multiple 3076 cars. They already struggle with 0.63 A/R and are very knock prone even with 0.82 A/R on stock CR.
If you add a better flowing comp wheel to that, you will not be able to utilize the extra air because of high backpressure. And you won't be able to utilize the midrange, because you can't boost over 2 bar without heavy knock.

K26/27 on a #6 will make the same as a GT3076R 0.82? can you also show this with any dyno results? on the same spec engine?

I don't have dyno graphs for that atm, but K26/K27 with modern KKK comp wheels makes definitely more power than a 3076/0.63 and is roughly the same as 3076/0.82 from my experiences with tuning. This is also reflected by similar IDC's between the K26/K27 and 3071/0.82.
You really think a K26/K27 is a horrible lagmonster, well it is, if you use 80's parts. If you use modern KKK parts found on various cars built in the last 5 years, then it's not.

I made roughly 490 (if im strict) and 500 if im casual on the 0.82AR 3076. Does the K26/27 make that power? (and did that on a non ported head, only wagner IM and SQ EM).

I want to see a dyno graph from that 3071/0.82 does not make that kind of power without meth injection. And if you use meth injection you can get upto 20% gains, so your point is moot. In fact Garrett rates the 3071R compressor as upto 460hp and 3076R compressor as upto 525hp.

I think the K26/27 turbo is inferior to the 3076 0.82AR. I think it is more equal to the 0.63AR equivalent.

That is the difference between me and you. You *think*, while I know, and have first hand experience. I have mapped 5 cars with 3071's on them, and I have mapped close to 20 cars with K26/K27's.
No sense debating that with what you *think*, because I guess that will always be right.

I have no hidden agenda promoting these turbos, they are just very good.

[A80Avant]

I have experience mapping multiple 3076 cars. They already struggle with 0.63 A/R and are very knock prone even with 0.82 A/R on stock CR.
If you add a better flowing comp wheel to that, you will not be able to utilize the extra air because of high backpressure.

I don't have dyno graphs for that atm, but K26/K27 with modern KKK comp wheels makes definitely more power than a 3076/0.63 and is roughly the same as 3076/0.82 from my experiences with tuning. This is also reflected by similar IDC's between the K26/K27 and 3071/0.82.
You really think a K26/K27 is a horrible lagmonster, well it is, if you use 80's parts. If you use modern KKK parts found on various cars built in the last 5 years, then it's not.

I want to see a dyno graph from that 3071/0.82 does not make that kind of power without meth injection. And if you use meth injection you can get upto 20% gains, so your point is moot. In fact Garrett rates the 3071R compressor as upto 460hp and 3076R compressor as upto 525hp.

That is the difference between me and you. You *think*, while I know, and have first hand experience. I have mapped 5 cars with 3071's on them, and I have mapped close to 20 cars with K26/K27's.
No sense debating that with what you *think*, because I guess that will always be right.

I have no hidden agenda promoting these turbos, they are just very good.

So on the GTX series, you are only theories again as you have not tested anything yet.

Are all K26/27 turbos that you have used on the UK cars you have tuned with the new wheels? If so, my offer stands and that will prove me wrong (or you for that matter)

My numbers on the 3076R have been done through my perfomance box. Recently a guy from germany said to me that my numbers seem to equate quite wheel with a rototest dyno numbers. However as i said, since the perfomance box and my excel is a personal measurement, im happy to compare with anyone that has the K26/27 that you have tuned. Simple and easy comparison.

You said it yourself, the 0.82 can go up to 525 and i measured somewhere between 490-500 on 2bar to the red line. Why is that difficult to comprehend? on similar roads and tests i had measured 425 on my 3071R 0.63AR with 2bar overboost and 1.7bar to the redline. Again within the limits of the turbo.I wasnt using meth injection and for your tuning information i was running 14deg timing on the 3071R without knock and 12.5deg on the 3076, both at 2-2.1bar at the time the boost peaked.(timing of course rised as rpms rose as well). Proof of no knocking was the engine which had NO pitting marks on the pistons, and combustion chamber even though while i had the motronic tune i was able to hear the knock!

And again, for the personal remarks, i wont say anything more than just that you are again trying to present an 'image' of yourself.
I dont present only what i 'think' and if you took the time to read the previous link i posted you'd realise that. Of course if the quotes of a good test is not going with YOUR experiences you simply disregard them. On the other hand, I present my own personal experience. You have mapped 25 cars and have your own experience. I therefore challenged you on a simple test. Do you want to take up the challenge? I think it will make a difference to David's decision to say the least.

Besides, you can say what you your experience is, but you are only one person and therefore can say whatever you want. Who are we to actualy believe you are NOT in an agenda?

[Jamo]

Dyno graph is on epics thread also see aronmatics thread making around 475 on a 3076 .63 with dyno plot

[A80Avant]

All i have heard about the K26/27 from this forum is that the top shelf is 450hp on our engines (on stock heads??). How is that anywhere near the 480+ that everyone is getting on the 3076 0.82AR?