Gt2871r on a clio?

[scotty2hotty81]

to be honest if you want low 300-320 froma small displacement engine , i would highly recommend ihi vf22 , on 1.8t it reaches 1bar by 2900 rpm with a good tubular exhaust manifold and will achieve 310-330bhp at around 1.4-1.5bar of boost so on a 2.0 engine i would presume spool time would be even better , some will call it chocolate turbo but ran on my mk4 gold turbo for 2 years with no issues and mapped by jabbasport

From what I have read on the Internet 1.8t responds well to a lot of turbos that f4r doesn't, i asked about the gt2871r as that seems to be used a lot, and on the 200sx, leaning towards the "disco potato" I think or maybe one from the gtx range as advised by stevie, as above not looked into ihi range only experience I have had with that company are superchargers on amg's and to be fair never had any problems, I'm also hoping to be running that sort of power at lower boost 1.4-1.5 I don't feel is needed, as said many times on this forum it's not all about what bar boost your running.

 

[T.Trophy]

Inlet manifold

If your measuring your boost at the inlet manifold (the same place as me) and it's showing 1.4 then your already past the intercooler, pipework and throttle body so there flow capabilities are irrelevant. Your looking for something post manifold causing a restriction.

 

[Chip-mk1]

If your measuring your boost at the inlet manifold (the same place as me) and it's showing 1.4 then your already past the intercooler, pipework and throttle body so there flow capabilities are irrelevant. Your looking for something post manifold causing a restriction.

If his intercooler is restrictive though, it will mean that the turbo has to work much harder to get 1.4 bar into his inlet manifold, ie boost might be 2 bar+ at the turbo housing potentially, in which case the exhaust side of the turbine is obviously having to work harder, which will in turn increase EBP as a result, and cause a flow restriction on the way out of the engine.
So I dont agree that just cause he has a lot of boost after his intercooler that automatically means he isnt suffering as a result of it.

 

[Gaz.]

Still love how the 2871r is berated on here. They're one of the quickest spooling turbos you can put on an SR.

 

[T.Trophy]

From what I have read on the Internet 1.8t responds well to a lot of turbos that f4r doesn't, i asked about the gt2871r as that seems to be used a lot, and on the 200sx, leaning towards the "disco potato" I think or maybe one from the gtx range as advised by stevie, as above not looked into ihi range only experience I have had with that company are superchargers on amg's and to be fair never had any problems, I'm also hoping to be running that sort of power at lower boost 1.4-1.5 I don't feel is needed, as said many times on this forum it's not all about what bar boost your running.

Scotty F4R's flow very well, how many other engines make nearly 350bhp @1 bar of boost? The problem is because of this they tend not to spool up at really low rpm unless you fit a stupidly small turbo which in turn strangles the top end. It's swings and roundabouts but there is a turbo out there that will give whatever power delivery or peak power anyone could want.

 

[Dan519]

Still love how the 2871r is berated on here. They're one of the quickest spooling turbos you can put on an SR.

makes me laugh. Seems like if 300bhp isn't enough you have to have 500 and nothing else will do

 

[T.Trophy]

If his intercooler is restrictive though, it will mean that the turbo has to work much harder to get 1.4 bar into his inlet manifold, ie boost might be 2 bar+ at the turbo housing potentially, in which case the exhaust side of the turbine is obviously having to work harder, which will in turn increase EBP as a result, and cause a flow restriction on the way out of the engine.
So I dont agree that just cause he has a lot of boost after his intercooler that automatically means he isnt suffering as a result of it.

Your right but looking at the spec of his car it's safe to assume he hasn't went for a fully forged engine with gas flowed head, tubular manifold GT2871R then stuck an eBay intercooler on there.... His intercooler pipework might be small diameter but it won't be smaller than the compressor outlet so won't make a massive amount of difference either, obviously he might benefit from larger pipework post Intercooler once the air is cooler and denser.

 

[T.Trophy]

makes me laugh. Seems like if 300bhp isn't enough you have to have 500 and nothing else will do

I think people fail to recognise that people who work in this industry do a lot of it for the love of doing projects like this. :rasp:

The real challenge is getting 500bhp to drive really well on the road, think gear dependant boost settings, boost vs tps maps and the obligatory LSD. Worst case scenario you can turn the boost back down untill you find a happy medium.

 

[Chip-mk1]

Your right but looking at the spec of his car it's safe to assume he hasn't went for a fully forged engine with gas flowed head, tubular manifold GT2871R then stuck an eBay intercooler on there.... His intercooler pipework might be small diameter but it won't be smaller than the compressor outlet so won't make a massive amount of difference either, obviously he might benefit from larger pipework post Intercooler once the air is cooler and denser.

It wouldnt be the first time Ive seen someone spend big money on an engine build and then scrimp on the intercooler TBH if he has got some random ebay rubbish on there!

 

[Chip-mk1]

I think people fail to recognise that people who work in this industry do a lot of it for the love of doing projects like this. :rasp:

The real challenge is getting 500bhp to drive really well on the road, think gear dependant boost settings, boost vs tps maps and the obligatory LSD. Worst case scenario you can turn the boost back down untill you find a happy medium.

Decent boost vs TPS maps can certainly totally transform the usability of a big power FWD car, I remember when I first started doing so a few years ago it was quite surprising the difference it made to how well you could pull out of bends etc.

I think a lot of people slagging off turbo trackday cars have probably never been in a really well mapped car with tps controlling the boost TBH, its just so night and day different to driving one that isnt mapped that way!

 

[Cooksport]

It wouldnt be the first time Ive seen someone spend big money on an engine build and then scrimp on the intercooler TBH if he has got some random ebay rubbish on there!

Pace Intercooler.

 

[Andrew Cooke]

Still love how the 2871r is berated on here. They're one of the quickest spooling turbos you can put on an SR.

it's all about the cams, SR20DET and F4RT have mild cams with almost no overlap so can live with the backpressure of a small turbine. The F4R has what is more like a race cam to a turbo engine so you have to size the turbo to suit, if you get it right it'll piss all over an SR20, get it wrong and it's a dog (relatively).

 

[Dan519]

it's all about the cams, SR20DET and F4RT have mild cams with almost no overlap so can live with the backpressure of a small turbine. The F4R has what is more like a race cam to a turbo engine so you have to size the turbo to suit, if you get it right it'll piss all over an SR20, get it wrong and it's a dog (relatively).

it's relatively simple to account for this by moving the switch points of the vvt. Everyone forgets you can raise the rpm that it engages aswell as altering the top switch point

 

[Gaz.]

it's all about the cams, SR20DET and F4RT have mild cams with almost no overlap so can live with the backpressure of a small turbine. The F4R has what is more like a race cam to a turbo engine so you have to size the turbo to suit, if you get it right it'll piss all over an SR20, get it wrong and it's a dog (relatively).

Yet, the most responsive 2871r setups on an SR have lumpier cams

 

[T.Trophy]

Yet, the most responsive 2871r setups on an SR have lumpier cams

I think your confusing response with power, better flowing cams will give more power for a giving boost pressure. But they will also increase the flow efficiency of the engine, therefore increasing the spool/response time.

 

[Gaz.]

I think your confusing response with power, better flowing cams will give more power for a giving boost pressure. But they will also increase the flow efficiency of the engine, therefore increasing the spool/response time.

No. I'm not.

I'm just not fussed for chasing power and having a car that drives like a laggy pile of s**t. Like I said, the cams help make it more responsive on an SR. The aftermarket profiles probably aren't far off those of the standard Clio cams. This is why it amazes me that the 2871r is labelled as crap on here.

 

[T.Trophy]

Well your the first person I've ever heard claiming that wilder cams with more lift/duration reduce spool and increase response.... Next you'll be telling me they made more torque as well. LoL

 

[Dan519]

No. I'm not.

I'm just not fussed for chasing power and having a car that drives like a laggy pile of s**t. Like I said, the cams help make it more responsive on an SR. The aftermarket profiles probably aren't far off those of the standard Clio cams. This is why it amazes me that the 2871r is labelled as crap on here.

you're mostly looking at 256/264/272 degree cams on the SR for aftermarket, and the lift is still less than an F4R stock cam. What's an SR20DET stock inlet cam? 9mm lift? and aftermarket is roughly in the 10 to 10.5mm region?

 

[T.Trophy]

Exactly, hence why they spool well as there still quite restrictive compared to a stock F4R. The general rule is the milder the cams the better low down torque and response, wilder cams for a better top end. Obviously which ever you choose you sacrifice the other end of the rev range.

 

[Dan519]

you can replicate a very similar effect with cam timing though. As i said a few posts earlier, clever use of VVT

 

[T.Trophy]

In theory the dephased state with zero overlap should work great for spool up, then swithching the VVT for a strong top end. How ever I'll just use my catcam vernier pulleys to keep things simple, plus they won't rattle around like a dephaser at 8k+

 

[Chip-mk1]

In theory the dephased state with zero overlap should work great for spool up, then swithching the VVT for a strong top end. How ever I'll just use my catcam vernier pulleys to keep things simple, plus they won't rattle around like a dephaser at 8k+

You probably dont want the timing advanced at the very top of the rev range, it will fill the cylinder better with it retarded at high rpm generally as the induction stroke timebase is so diminished. So you dont want the valve to shut as soon as you havent had as long to cylinder fill so it wont reach equilibrium with the inlet tract until the piston is further back up the bore.

 

[Andrew Cooke]

In theory the dephased state with zero overlap should work great for spool up, then swithching the VVT for a strong top end. How ever I'll just use my catcam vernier pulleys to keep things simple, plus they won't rattle around like a dephaser at 8k+

I think you have that back to front, a small turbine won't be restrictive (ie more pressure in the exhaust manifold than the inlet manifold) until it makes boost, so you can run the overlap at low boost and gain spool, but you will need to get rid of it on boost/high revs. Simply put, if TIP>MAP then dephase the cam. If you get the turbo right TIP will never be greater than MAP (on throttle) and the cam can stay advanced to make the big power. <<oversimplification warning>>

 

[T.Trophy]

Your right Chip + Andy, think I should just stay away from posting whilst intoxicated. :clown:

I wouldn't mind but I've even worked through this scenario when my car was fitted with a smallish turbo so have first hand experience of it and quite good knowledge. Not sure what thought process I was apllying when I posted it, I blame the beer, I can only apologise, then get my coat

 

[Chip-mk1]

Lol, fair play, certianly took that one on the chin well

 

[T.Trophy]

Well, when your wrong, your wrong...... LoL

As soon as soon as I read your reply I realised then Andy simply backed you up. I'll not be losing any sleep over it though

 

[scotty2hotty81]

:cheers::argue:

 

[Gaz.]

Well your the first person I've ever heard claiming that wilder cams with more lift/duration reduce spool and increase response.... Next you'll be telling me they made more torque as well. LoL

Don't see why it's so ridiculous TBH, more exhaust out = more gas into the exhaust turbine at least.

It's something that seems to get banded about on SXOC anyway, unless they're just using the cams on a .64 to make up for the lack of puff at high revs.

 

[Luke.]

Well...

I drove a megane with the 2871 fitted to it the weekend after it made 399bhp on the rollers..

Lag you say?

You wouldn't even know it existed, the power delivery was instant, so smooth and awesomely quick.

Quite easily the fastest, smoothest and best car I've ever driven..

Will be looking forward to getting one fitted to my Clio in the new year..

 

[Dan519]

Well...

I drove a megane with the 2871 fitted to it the weekend after it made 399bhp on the rollers..

Lag you say?

You wouldn't even know it existed, the power delivery was instant, so smooth and awesomely quick.

Quite easily the fastest, smoothest and best car I've ever driven..

Will be looking forward to getting one fitted to my Clio in the new year..

lol, I wondered if this would get posted to this thread. I drove it too. If you've got lag or can't make power with that turbo, you've done it WRONG. Such an awesome drive!!!

 

[Luke.]

lol, I wondered if this would get posted to this thread. I drove it too. If you've got lag or can't make power with that turbo, you've done it WRONG. Such an awesome drive!!!

Amen to that.

Well done Cooksport and K-Tec..

 

[RSTuning]

If you've got lag or can't make power with that turbo, you've done it WRONG. Such an awesome drive!!!

The OP has a Clio F4R with wilder cams compared to the F4RT. Josh has a tubular manifold compared to the restrictive LOG the OP has.......

Also nobody said they are a laggy turbo, just more lag compared to a 2860 which IS the turbo he would get better use from in his situation. I agree you can make power from the 2871 but the turbine is restrictive and you will be stock at 400hp regardless although some dyno's may show different.

 

[Andrew Cooke]

The OP has a Clio F4R with wilder cams compared to the F4RT.

 

[Dan519]

View attachment 68283

that just makes me want to drop an NA exhaust cam in an F4RT

 

[Andrew Cooke]

that just makes me want to drop an NA exhaust cam in an F4RT

That may, or may not, be a great thing to do. Only trying it would confirm. I think I'd want an adjustable pulley fitted at the same time though.

 

[Chip-mk1]

We do similar on the vauxhall turbo engines, fit the cams from the N/A variant instead as the factory ones are so mild, works well.

 

[T.Trophy]

Well done Josh+Ktec, 399bhp is a pretty respectable number from a 2871r, how much boost you squeezing through it to hit that? looking at the graph on ktecs blog you can see how much better the spool up is on your lump compared to a low comp (8.5:1) F4R on OE cams. Torque is a lot better as well. Seen's as you have your head ported I can only guess that the milder cams of the F4RT are helping a lot.

If you've got lag or can't make power with that turbo, you've done it WRONG.

Thanks, obviously when I said it was laggy that was in comparison to a GT28RS that I ran. In places below 4500rpm the 28rs was up by 30bhp and 30lb/ft. If you review both my GT2871R dyno run and Ktecs graph of a customers car running a 2871, you'll find there almost a mirror image of one another. I admit I did suffer at the top end of the rev range due to the logg maifold and looking at the figures Josh has pulled you can see that a tubular manifold will flow much better at the top end. As I'm keen to learn new things feel free to post the graphs up of any F4R engines that you've done running a GT2871R so we can compare, plus it'll show both myself and Ktec how it should be done :rasp: The truth is thats just how that turbo performs on an F4R running stock cams........ It would be nice to see how well there Blue clio spools on a tubular with the Tial turbine housing though.

Heres a link to Josh's graph on Ktecs blog http://www.k-tecracing.com/news.asp (its dated 19th Dec 2011 for anyone looking for it in the future ) further more Ktecs customers car running a GT2871R is on the same link but dated (5th Sep 2011) and for those interested heres my GT2871R graph

If I was doing another 350-400bhp turbo build I'd be using a set off F4RT cams and a new GTX28 60/63R turbo you'd have even better spool than what Josh has whilst still having a compressor wheel that can outflow the turbine wheel.

Well...

I drove a megane with the 2871 fitted to it the weekend after it made 399bhp on the rollers..

Lag you say?

You wouldn't even know it existed, the power delivery was instant, so smooth and awesomely quick.

Quite easily the fastest, smoothest and best car I've ever driven..

Will be looking forward to getting one fitted to my Clio in the new year..

Glad you liked it mate but as above don't expect the same levels of response by simply bolting it to your car, it will be laggier. The only worry I would have (again from personal experience) is gearbox reliability. By all means try an LSD and bracing plate but if it was me I see the Megane R26's as being a much better platform for big power turbo builds.