Turbo's

Mad

Mad

Well-Known Member
I am doing some research on turbo's at the moment and would appreciate it anyone who has a dyno report of their car would reply back with a copy of their graph and brief spec of their engine.
I am looking at the differences in turbo's with regards to bhp, power delivery, torque and drop off.

Any information would be useful.

Thanks
 
M

Makaveli_se7en

Member
The problem you have there is the turbo is but one of many factors in the engine power delivery. You will be able to get a rough idea but unless you put the different tuirbos on the same engine (on the same dyno), you will never get the true picture.
 
PobodY

PobodY

Moderators
Staff member
How much can be gleaned from looking at the compressor maps? - I do periodically look at the ones on the Garrett website, but I'd be lying if I said I really understood what they tell me.

I suppose the issue is translating the flow and pressure of a turbo into a "real world" power figure.

Ed, I completely agree with that; I've seen three or far cars with the same standard turbo (T2804?) achieve quite different power on the same dyno on the same day. - Different exhausts, different air filters, different plugs, different values of "about 1 bar"... the list goes on.

I suppose if you get enough data for a given turbo you can quantify the effect it has. I'm just not sure we can generate enough data.
 
Mad

Mad

Well-Known Member
Yes, agree.

Different dyno's and car setups are going to give different figures.

In the under 400bhp section, I think that most people have got a good idea of what turbo and setup works best.

Im really interested in the 400bhp + areas with the GT3071R, GT3076R + twin scroll, GT30/40, GT35/40 and GT3582R with .63 and .82 housings where owners are going down different routes to get the power. Its never going to be perfect but looking for ideas for future development.
 
Fast Guy

Fast Guy

Moderators
Staff member
Why not speak to someone like Mark Shead? I'm sure he's done most combinations by now, albeit on the Evo.
 
M

Makaveli_se7en

Member
Compressor maps tell you next to nothing other than will your engine running line will fit or not. Efficiency islands will give you some indication of outlet temperature.

I will write a more detailed post on my thoughts regarding turbo matching for 500bhp+ later this evening (too hungry now, need to eat first :lol:)
 
campbellju

campbellju

Moderators
Staff member
Mad4it said:
Yes, agree.

Different dyno's and car setups are going to give different figures.

In the under 400bhp section, I think that most people have got a good idea of what turbo and setup works best.

Im really interested in the 400bhp + areas with the GT3071R, GT3076R + twin scroll, GT30/40, GT35/40 and GT3582R with .63 and .82 housings where owners are going down different routes to get the power. Its never going to be perfect but looking for ideas for future development.
Click to expand...
Over the years there has been quite a lot of experience on the forum in the range of 400-500hp turbos and recently people are learning about the 500 to 600hp turbos. My personal opinion is be realistic on your target first and then fit the smallest turbo and a/r you can to reach it. If you know what target or range you want to hit then between the forum memebers there will probably be a concesus of what works.
 
Fusion Ed

Fusion Ed

Active Member
Helps if you know what you want. Recently fitted a 3071.64 which I had to say worked really well as a half way between 28/3071.
 
Mad

Mad

Well-Known Member
I am looking for comparisons between GT3076 (.63 and .84) GT35 (.63 and .84) and GT30/40. As stated earlier, its the 500 - 600bhp mark which is the grey area so any graphs with those turbo's would be of great benefit.

Tar
 
campbellju

campbellju

Moderators
Staff member
Below is Sascha's RR plot with 280 Kent cams fitted. He had 264's fitted previously. I'd need to check my logs but I don't remember seeing much improvement in terms of boost response before and after fitting the cams. IIRC, the biggest difference was it allowed the engine to breath more at high revs. Previously the air flow used to drop off after 6.5K but afterwards it held a similar value to 7.5K. The dyno plot stops at 6.8 but on the road and from the logs the car was still pulling so you get a 2K window on the drag strip from 5.5 to 7.5K where you constantly make around 500hp with a smooth(ish) transition from 4.4K where is comes on boost.

Most of the benefit came from hours and hours of longwinded mapping, flooring it from 2K, 3K, 4K, 5K and controlling the boost and fueling. There wasn't a sudden improvement in taking out the 5K kick but each time we adjusted something we got it closer to the result below. The water injection is a safety feature and I believe makes less power unless you use additives rather than water and increase ignition. The RR experience is another story but we continued fettling the map afterwards playing with boost and WI smoothing everything out.

It still makes boost too late for my liking but I think Sascha wants more power so is looking for a bigger setup :oops:

 
campbellju

campbellju

Moderators
Staff member
Big Rob (John Doe's) plots are helpful to understand a possible cause in my mind as I spent a lot of time sorting the same issue on my own 3071.

My belief is tuners have a limited time to map a car and they want to make sure it doesn't blow up. the point at which the engine makes +ve boost can vary depending on engine load and especially at gear changes. To get this perfect takes a lot of fettling of the fuel target along with the accelerator pump so you're using the correct control tool at the correct time.

Looking at Rob's plot he posted elsewhere, at 4.7K rpm the engine is in vacum but is showing an 11.6 AFR and I expect the ignition is also retarded accordingly. You will end up with a colder exhaust gas that is sub-optimal. I think at 4.8K the air flow gets to a critical point where the turbo spools and the car goes ballistic as the map gets closer to what is optimal and spools faster as EGT's rise.

It takes me weeks to map a car to the point I'm happy with it. I'd never be a tuner as you are expected to perform miracles in a morning that will work perfectly whether you use the throttle like an egg shell or a switch and whether it's winter or summer.

In terms of turbo choice, no matter what you do I believe this will have the biggest effect on your turbo's transient response and maxium hp. The rest is just optimisation and until one of these new generation turbos come out that I keep hearing of you will always have to compromise between the two.
 
M

Makaveli_se7en

Member
Hi Dan, I think in all honesty you seem to be looking for something that doesn't exist; a 500-600bhp turbo thats will respond like a 400bhp turbo on the same engine. Its just doesn't exist. In order to achieve that sort of response you need to look at the entire engine system, which is why I've pretty much started from scratch with my spec.
 
Mad

Mad

Well-Known Member
Makaveli_se7en said:
Hi Dan, I think in all honesty you seem to be looking for something that doesn't exist; a 500-600bhp turbo thats will respond like a 400bhp turbo on the same engine. Its just doesn't exist. In order to achieve that sort of response you need to look at the entire engine system, which is why I've pretty much started from scratch with my spec.
Click to expand...
:lol:

I think the answer is that it does not exist yet. With the emmission laws becoming tighter, high end car manufactuers are lowering their engine sizes and introducing turbos to keep on par with their current power figures. It will take time but will benefit Turbo Car owners in the future Im sure.

Although a 600bhp turbo spinning up as quick as a 400bhp turbo would be ideal (although not yet possible), what Im looking for is the quickest spool up turbo for power around 550 - 580bhp.

Unfortunately, GTiR's have not been developed as much as Evo's and Scoobies so it is all about development and picking up ideas from other people, not looking for something that does not exist.

I appreciate engine spec also contributes towards overall power and spool and with higher compression and lower spec cams on my car etc etc, Im pretty happy with the setup.

GT3076 has been used quite often and produces circa 500bhp.

I would really like to know figures on a GT30/40 with .84 and .63 exhaust housings as well as a Scooby Clinic GT30 Billet with similar housings.

Anyone??????
 
Last edited by a moderator:
Mad

Mad

Well-Known Member
Yes, I remember. I did speak to him a while back. A friend of mine has a GT30/40 and that spins up quickly. Not sure on exhaust housing size but is proabably 500 +.

Tar. I will go look up his thread.
 
T

Thor

Member
I have fitted the GT3040 with A/R 0.87 and the spool is similar than the GT3076R. About hp i don´t can tell more at the moment because i not had time too check them.
 
Empty Pockets

Empty Pockets

New Member
I think i have Mikes graph on my computer somewhere, 570 on pump / 620 on race fuel, was a bit of an animal and still the highest powered R in the uk (with proof), if you have no joy finding it on the forums, i'll dig it out and post it up, with Mikes consent obviously :)
 
You must log in or register to reply here.
Top