tooquicktostop Posted February 4, 2010 Share Posted February 4, 2010 Thanks mate, with this thread I was getting worried that the single turbo FAQ I'm working on would be a waste of time. It's 6 pages so far am only scratching the surface of the considerations. I'll certainly take into account a few of the comments made here though, there are some very valid ones. Look forward to reading it, I wish I had such a reference way back in the day, I have learnt the hard way and only now with several cars and lessons learnt the car spec that suits me and my skill/driving style I think it will be a very useful tool I have been to many a rolling road session with this club where disappointed faces have come out of the dyno cell at 340-400 BHP,this number is disappointing only because of the BHP bug, this level of power if huge compared to most club dyno days, I have been to a few ! I also know there is a limit to pump fuel and a 3 litre engine, the quest will reach a peak, what then excites me and provides the interest Quote Link to comment Share on other sites More sharing options...
nigelboyne Posted February 4, 2010 Share Posted February 4, 2010 Thanks mate, with this thread I was getting worried that the single turbo FAQ I'm working on would be a waste of time. It's 6 pages so far am only scratching the surface of the considerations. I'll certainly take into account a few of the comments made here though, there are some very valid ones. thats great homer we really can do with it. personally i am looking for a na drive up to 3k as this is were 80 percent of my driving is done. so no boost up to 3/3.5 k then i want the car to pull hard and fast to 200mph with ease and be reliable. Quote Link to comment Share on other sites More sharing options...
Terminator Posted February 4, 2010 Share Posted February 4, 2010 Id not want to drive a supra with lower compression than stock tbh. With you there. I love the power delivery of a high compression set up, it is so smooth and even, with 280 cams too. Quote Link to comment Share on other sites More sharing options...
johnny g Posted February 4, 2010 Share Posted February 4, 2010 Id not want to drive a supra with lower compression than stock tbh. If you go 3.4, you'll gain in torque a little what the compression loses you... Just a thought. Quote Link to comment Share on other sites More sharing options...
sdistc Posted February 4, 2010 Share Posted February 4, 2010 For me it's all about matching the parts choice and turbo to your desired power band. Peak BHP is a meaningless figure, it's all about power delivery. ... As usual, wise words from you, Darryl It's definitely about recognising your own driving style and preferences. A lot of people seem to try to impress others, instead of pleasing themselves, with modifying their car - and end up with something less than totally satisfying. Quote Link to comment Share on other sites More sharing options...
JamieP Posted February 4, 2010 Author Share Posted February 4, 2010 Basically what im looking for is the fastest spooling highest bhp i can get on pump fuel, a 3.4 stroker kit on a 71mm turbo is most likely the best setup out there imo but im not gonna do the 3.4 just yet, maybe next year. Quote Link to comment Share on other sites More sharing options...
johnny g Posted February 4, 2010 Share Posted February 4, 2010 Ahh therein lies the debate that has gone on here - the definition of quick spooling and the definition of high bhp?! Anything in mind? Quote Link to comment Share on other sites More sharing options...
Homer Posted February 4, 2010 Share Posted February 4, 2010 As you know my car has plenty of low/mid range torque, thing is i dont really use it, i either drive slowly, and im nowhere near using the midrange, or i want to go for it and im way past the midrange. Im not saying i want a laggy car, but to lose a little spool for a lot more top end sounds good to me. I think we're both saying the same thing - match the configuration to your desired power band. Your car is exceptional in its power delivery - great low, mid and high range power. However, as you say you don't make much use of the low/mid range and as such a large capacity turbo with (albeit already installed) components would help make more use of the power band that gets the most use. For those that use their cars as daily drivers or are simply after a very high torque car that can be driven with ease, turbo lag (or spool as it would be better termed) is a very big deal. It needs to be balanced against driving style and *spool* (not lag) characteristics. Edit - BTW, Jamie, not at all taking a dig at what you've posted, I agree with pretty much all of it. I just don't want to see people reading the replies and then dig themselves into *desiring* a bhp/turbo choice without understanding all the other considerations. That's why an FAQ/single turbo guide is in being written, difficult as it is Reading your updates is always a pleasure and love all the honest and open first hand feedback. It's very refreshing from the willy waving we see on supraforums Quote Link to comment Share on other sites More sharing options...
tooquicktostop Posted February 4, 2010 Share Posted February 4, 2010 Basically what im looking for is the fastest spooling highest bhp i can get on pump fuel, a 3.4 stroker kit on a 71mm turbo is most likely the best setup out there imo but im not gonna do the 3.4 just yet, maybe next year. You can drive let face it, no blowing wind up your a** either you just have a good skill level, better than mine and you use the full BHP the car delivers You also seem to want to own the fastest and most powerful street car in the UK if possible and you have the finance to do it, that is great for the club and creates interest, I have not owned a Supra for months but still stay around as I think the club is great, full of characters willing to push the boundries and get some awesome power figures from an old jap sports GT , I will watch with interest what you manage to gain in power We have come a long way from the TF days Quote Link to comment Share on other sites More sharing options...
JamieP Posted February 4, 2010 Author Share Posted February 4, 2010 (edited) You can drive let face it, no blowing wind up your a** either you just have a good skill level, better than mine and you use the full BHP the car delivers You also seem to want to own the fastest and most powerful street car in the UK if possible and you have the finance to do it, that is great for the club and creates interest, I have not owned a Supra for months but still stay around as I think the club is great, full of characters willing to push the boundries and get some awesome power figures from an old jap sports GT , I will watch with interest what you manage to gain in power We have come a long way from the TF days We certainly have, Its all a learning curve mate and i still am learning:) Its all about compromise, yes i do want to be the fastest but you cant have a car that does everything, not being rwd anyway, i enjoy the odd track day as much as i enjoy a bit of drag racing and as much as i enjoy tearing up the streets, i just want a car thats pretty good at everything. I know if i come up againt Dude on a drag strip he is gonna wipe the floor with me but if i have a car that beat 90% of people in all areas i think i have cracked it. I think we're both saying the same thing - match the configuration to your desired power band. Your car is exceptional in its power delivery - great low, mid and high range power. However, as you say you don't make much use of the low/mid range and as such a large capacity turbo with (albeit already installed) components would help make more use of the power band that gets the most use. For those that use their cars as daily drivers or are simply after a very high torque car that can be driven with ease, turbo lag (or spool as it would be better termed) is a very big deal. It needs to be balanced against driving style and *spool* (not lag) characteristics. Edit - BTW, Jamie, not at all taking a dig at what you've posted, I agree with pretty much all of it. I just don't want to see people reading the replies and then dig themselves into *desiring* a bhp/turbo choice without understanding all the other considerations. That's why an FAQ/single turbo guide is in being written, difficult as it is Reading your updates is always a pleasure and love all the honest and open first hand feedback. It's very refreshing from the willy waving we see on supraforums Cheers mate, its been a good couple of years for development, many things have been learned. Edited February 4, 2010 by JamieP (see edit history) Quote Link to comment Share on other sites More sharing options...
sdistc Posted February 5, 2010 Share Posted February 5, 2010 yes i do want to be the fastest .... I know if i come up againt Dude on a drag strip he is gonna wipe the floor with me but if i have a car that beat 90% of people in all areas i think i have cracked it Mate, you know your car is fast enough when only other Supras (and litre bikes) are your only competitors. Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 5, 2010 Share Posted February 5, 2010 What about a divided housing since you have a divided manifold? I'm looking into this for mine to help spool. SP do a divided housing for the 6765 & just seen that Precision have something similar coming out? Keep reading differring stuff on whether they will actually help but Garrett have this on thei tech site: http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech102.html#c If you're upgrading to a 71 it might be worth getting a divided housing on from the get go, prolly little to no extra cost, I'm pretty sure your manifold is divided isn't it? I'm thinking rather than picking up a .96 undivided to get extra top end I might pickup the divided equivalent Quote Link to comment Share on other sites More sharing options...
JamieP Posted February 5, 2010 Author Share Posted February 5, 2010 It would have to move the equivalent air of a open .96 to make me interested. What would that be? 3rd again aint it? Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 5, 2010 Share Posted February 5, 2010 Yeah 3rd again sounds about right, 0.82 un = 1.0 div so I guess 1.25 if they do one. Larry @ SP says $299 for a housing, a thread is about to go on SF with results of the new SP divided housing, will link it when available Quote Link to comment Share on other sites More sharing options...
johnny g Posted February 5, 2010 Share Posted February 5, 2010 T71 Billet does sound like an ideal turbo - are they doing a T74 Billet, Jay? Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 5, 2010 Share Posted February 5, 2010 T71 Billet does sound like an ideal turbo - are they doing a T74 Billet, Jay? I thought they already did ages ago? Quote Link to comment Share on other sites More sharing options...
johnny g Posted February 5, 2010 Share Posted February 5, 2010 I thought they already did ages ago? Oh I don't know - I lose patience very quickly with the Precision website! And SF annoys me. Hmmm. T71 Billet, that might be nice on the MR2. Quote Link to comment Share on other sites More sharing options...
imi Posted February 5, 2010 Share Posted February 5, 2010 For me it's all about matching the parts choice and turbo to your desired power band. Peak BHP is a meaningless figure, it's all about power delivery. Jamie for exmaple drives the car hard and seems to spend most of the time in the top third of the engine rpm and makes full use of the power available. This suits a larger turbo, higher lift cams, lots of fueling, high end ECU, etc to get the most amount of power in that rpm band. My driving style (and that of a few others) is very different. I don't drive the car hard and love having a large amount of low/mid range torque. It's more about having effortless power at lower range. As such the T67dbb setup with stock cams and decent fueling and ECU was perfectly matched to my driving style. I wouldn't want to sacrifice that low end torque for a more powerful high end as 99% of my time behind the wheel would not be spent in that high rpm band. I understand fully why some people like Jamie would prefer a larger turbo setup and a more peaky power band, but it's not for everyone. sums up the thread nicely for me.... Quote Link to comment Share on other sites More sharing options...
Chiefgroover Posted February 5, 2010 Share Posted February 5, 2010 I use an 8K rpm limit and sometimes put it up to 8.5K. I like the 4K off boost, 4K on boost driving. Why? various reasons. 1. Traction - when roads are wet greasy I can drive up to almost 4k with very very little chance of wheelspin or the back letting go due to my slightly early on the throttle corner exiting style. 2. Fuel economy - no real amount of boost means better economy, I really can't grump about my fuel economy. 3. Only the follwing races from 2K rpm. A. your granny, B. RLTC users c. people who dont understand their engine. I really dont want loads of torque @ 2500rpm as I see no point as my CLK55AMG just spun wheels at those revs. Quote Link to comment Share on other sites More sharing options...
johnny g Posted February 5, 2010 Share Posted February 5, 2010 I really dont want loads of torque @ 2500rpm as I see no point as my CLK55AMG just spun wheels at those revs. It's nice to overtake on the motorway, though, without downshifting. Quote Link to comment Share on other sites More sharing options...
Luxluc Posted February 5, 2010 Share Posted February 5, 2010 It's nice to overtake on the motorway, though, without downshifting. Some people will say yes, others would like to downshift and pull up to the rev limiter then. Quote Link to comment Share on other sites More sharing options...
johnny g Posted February 5, 2010 Share Posted February 5, 2010 Indeed - it's good to see how people differ in there driving styles. Quote Link to comment Share on other sites More sharing options...
csa Posted February 5, 2010 Share Posted February 5, 2010 lag/spool/full pressure are all very subjective terms that's only meaningful to the "eye of the beholder". For me the only meaningful thing to compare on setups aiming at different purposes are the width of the powerband, and for an engine maintaining the stock rev limiter(or 7K for that matter), for me, is what sets the limits of turbo size. I see no problem in having a turbo spooling at 5k rpm if you can pull it through to 9k, but for me, having a rev limit at 7500, Id never have anything later than 3800-4000 as I find it very annoying, drying in car with powerband of sub 3k rpm, whether being on the street or track. …just my 50c Quote Link to comment Share on other sites More sharing options...
dude Posted February 5, 2010 Share Posted February 5, 2010 I thought you ran the AFC/ITC combo? Blowing the odd tip off the sparkplug now and again The F-Con had issues with 'unlocking' and who could/couldn't map it, didn't it? I'm not criticising your setup back then, I'm just saying now it's a lot more achievable and durable due to the gear and experience in the community. No Ian thats what im running now and can't think of anything I would change to, just saying its relatively old hat but look how many big power cars run it. Quote Link to comment Share on other sites More sharing options...
dude Posted February 5, 2010 Share Posted February 5, 2010 Yep. And as for bigger turbos, I think it's false economy to go bigger - you can't run the decent timing to make the power, meaning you have to run more boost on less timing.. so it becomes an exercise in futility. I would say that even a 71 mm is probably too big to run efficiently at high boost. Have I missed something here, the bigger the turbo the more boost it needs to be efficient, no point in running my 76 anything under 1.8 bar:taped: Quote Link to comment Share on other sites More sharing options...
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