View Full Version : Does the IHI have the same lag as a standard turbo?
Hi all,
I understand that the IHI Turbo used in the popluar BT conversions... is Roller Bearing type.
So from what I've been told - Roller Bearing Turbo's don't hardly have any lag.... as they're sposed to spin up very quick etc...? is this true?
So... What I'm trying to get at is... if I went IHI would I get more or less lag than the standard setup in my LCR?
Thanks
moved, funnily enough, to big turbo discussion
in answer to your question, yes slightly more lag, its a bigger turbo with a larger capacity, so will take longer to reach full boost compared to the smaller k04
paul26982
29-11-2006, 11:33
i thought they wernt as laggy, more bottom end than top
minimivic
29-11-2006, 12:21
IMHO Lags a funny word really.
The way I see it is: a standard car is designed to be smooth and efficient. So when we go big turbo do we really care if the car is as smooth and efficient. Lag is really only relevant when accelerating (using the same gear) so why not just change down a gear and let the revs overcome the lag for us? That what most do anyway when wanting power to overtake. What I mean is if a turbo produces good boost at 3500rpm then don't plant the throttle at 2000rpm and expect it to do anything.
Also if you go BT the car can be driven off boost most of the time making it more efficient on fuel. Its similar to my VTEC mini under 6k and its a normal car above 6k its a race car so most of the time its returning 35mpg but when driven hard it goes down to around 20mpg.
Sorry its a little off topic but I feel its relevant.
Just off to put the flame suit on, but open to discussion.:think:
I'm very interested in this. I think that what you're describing is "boost threshold" rather than "lag". Correct me if I'm wrong.
I'd be interested in seeing, somehow, how the different big turbos compare when it comes to the boost onset, i.e. when they start spooling and when they're fully spooled.
Reading between the lines, Vic (?) says, perhaps this is only really relevant on a road car - but that's what I drive :D
I know that one thing I love about my K04/LCR is how the boost is there from about 3,000 onwards, making 6th gear heavenly, and while more top-end would be nice, I wouldn't what to compromise too much on this boost response.
I've never really seen any graphs/figures/whatever that compare, say (Please shout up if I've these specs if I've got these names wrong):
GT2X Eliminator (280bhp)
GTRS Eliminator (340-360bhp)
GT28RS .62 (340bhp)
GT2871RS (360bhp)
IHI VF34 p18? (320bhp)
IHI VF34 p20 (335bhp)
I know the IHI Boys (VF34 p18) have often said that it spools like K04-023, and while it might "Only" have 320bhp top end, it's probably a better choice, on the road, than a GT2871RS.
I also know that the IHI boys have said in the past that you can sit in top gear (5th for most of them) off-boost and pootle along (60-80) getting, probably, better MPG than a K04-023, where at the same speed, you're on/off boost...
Does anyone have any comment?
ibizacupra
29-11-2006, 20:54
you will be pulling well from mid 3K rpms on VF34..... and continue to pull more and more to >7Krpm
not as in ya face torue delivery as a chipped k04 would be, and less bottom (sub 3K) punchy, but different league...
and then there's mitsi based turbo's like I have evolved onto these days, which makes vf34 seem like a wheezy k03. 4K onwards manic pull to >8Krpm (but this is for serious modders only, and mandatory internal mods req'd)
cruising on VF34 was as economical if not better when off boost. Normal side effect of mapping anyhows.
I reckon vf34 running quite hard like mine used to 330bhp and a .20 housing version would be 340 ish bhp. The fun does not really start until a genuine 375bhp+ has been achieved maybe even 400bhp+.:D
ibizacupra
29-11-2006, 21:13
or even 500bhp..... coming soon to an ibiza somewhere close to me real soon.
how daft is that!
nutts
As a track car when its on the boil all the time its very important. I still think for someone looking for a good road going setup the old Pe1820f had a lot going for it in the 380-390bhp region. Its only what i feel not what i know though.
jonathanp
29-11-2006, 21:31
bill how does yours compare to the VF34 or K04? Is it a TD unit you're using?
reason I ask is that i've wondered what spool up would be like on a smaller version of your turbo set up to produce around 400bhp at 7-8k rpm
Updated my post, but you've quoted me :doh:
Where does the p20 spool then? Scotch John seems happy with his, says it's about 3500-4000.
You're all certifiable. 375bhp in a front wheel drive car and traction must be a real problem (even mine can be a handful), 4wd and I bet clutches get a hard time. You can't win.
"I'd be happy with 320-340 ish"* with some decent useability.
*I bet every one of the BT Boys has said that a least once before.... :D
ibizacupra
29-11-2006, 22:17
As a track car when its on the boil all the time its very important. I still think for someone looking for a good road going setup the old Pe1820f had a lot going for it in the 380-390bhp region. Its only what i feel not what i know though.
not just a track car gary. (there's another road car being built to same spec shortly)
its every bit as drivable as the PE before it with almost no difference in when power starts to pull strong.
sub 4K its slower, but thats only cos its daft as a brush when its up at 4K and beyond.... (off gauge boost from 4K if you want)-30psi gauge and its been pegged to a datalogged 37psi (sensor max). - completely silly levels I would not advise, but when it goes, by christ it goes... I have 10-12psi available from 3500rpm and off gauge from 4Krpm
in fwd its... as you would expect.... traction limited, but no worse (possibly better than PE) as its torque delivery is less aggressive but more sustained. (flat)
PE was working hard to get the high 300 numbers on the JS mani...setup of before.
I changed my mani an turbo so its a combination of parts which give the results, so spool on mine is maybe better due to equal length, but flow ability is massive.
ibizacupra
29-11-2006, 22:19
Updated my post, but you've quoted me :doh:
Where does the p20 spool then? Scotch John seems happy with his, says it's about 3500-4000.
You're all certifiable. 375bhp in a front wheel drive car and traction must be a real problem (even mine can be a handful), 4wd and I bet clutches get a hard time. You can't win.
"I'd be happy with 320-340 ish"* with some decent useability.
*I bet every one of the BT Boys has said that a least once before.... :D
P20 did'nt make much difference to spool.... and side by side you will struggle to see much difference between em.
not just a track car gary. (there's another road car being built to same spec shortly)
its every bit as drivable as the PE before it with almost no difference in when power starts to pull strong.
sub 4K its slower, but thats only cos its daft as a brush when its up at 4K and beyond.... (off gauge boost from 4K if you want)-30psi gauge and its been pegged to a datalogged 37psi (sensor max). - completely silly levels I would not advise, but when it goes, by christ it goes... I have 10-12psi available from 3500rpm and off gauge from 4Krpm
in fwd its... as you would expect.... traction limited, but no worse (possibly better than PE) as its torque delivery is less aggressive but more sustained. (flat)
PE was working hard to get the high 300 numbers on the JS mani...setup of before.
I changed my mani an turbo so its a combination of parts which give the results, so spool on mine is maybe better due to equal length, but flow ability is massive.
Intresting stuff. Must be a fun car to drive.
traumapat
30-11-2006, 07:40
we are forgetting the smaller ihi vf24. coming from a mapped k03s there is slightly more lag but less than i expected. powers maxed out at 320bhp iirc
the real difference imo is that the power stays strong right through to 7k rpm. it just keeps going. very different car.
ibizacupra
30-11-2006, 09:17
Intresting stuff. Must be a fun car to drive.
fun as in... scarey to be honest.,
I think I can drive a bit... but this has to be very much respected. On the public road, with cambers, bumps, potholes etc, its lethal! a std ibiza would have me I would imagine. smoother surface all is better but a handfull. traction is better than hoped tho considering the headline numbers, which is down to the torque level being progressive and not high.
revised front end suspension setup completely just, with test day saturday to see if its better.... which it should be.
its daft & very scarey. you would annihalate anything in it up your way.
ibizacupra
30-11-2006, 09:19
my fear of IHI's given my experience of them is they are fragile when pushed too hard. good package and I rate them higher than a GT28 RS, but they have limits, and eager as they are to produce almost any boost you ask of them mid range, they can eat themselves in the process. ~(bearings or heat damage to exhaust housing)
leonturboboy
03-12-2006, 08:14
my fear of IHI's given my experience of them is they are fragile when pushed too hard. good package and I rate them higher than a GT28 RS, but they have limits, and eager as they are to produce almost any boost you ask of them mid range, they can eat themselves in the process. ~(bearings or heat damage to exhaust housing)
wow, sounds out of this world. cant wait for my ihi now!
@badger, you building a road car for yourself with same spec?
ibizacupra
03-12-2006, 11:14
wow, sounds out of this world. cant wait for my ihi now!
@badger, you building a road car for yourself with same spec?
no this is a customer car.
ibizacupra
03-12-2006, 17:47
some interesting figures... been setting up boost controller so been looking a bit closer.
15psi is showing just about @ 3400rpm, and by 4000rpm, off gauge (30psi) if allowed. spool is looking better than the PE1820 I had on before.(very close on spool considering the huge size difference between them. Mitsi hybrid has massive compressor and enormous turbine compared to the PE/IHI unit)
Bill
As we discussed I think you suggested running 300hp utilising a VF34 p20 which shouldn't destroy or cause heat issues for my track work.....should be reliable on those settings.
IHI seems a nice progressive delivery looking at various logs. APR stage 3 available only for TT and S3 at present.
What's your oppinion of the eliminator range.....they appear from what I've read is that they are very laggy?
Anyone got any dyno logs on these.
Ian
ibizacupra
04-12-2006, 08:43
modest boost levels, power level and sensible tuning IHI is great.
Its fitment manifold wise is a complete 'mare however on the available cast manifold. once fitted its ok.
Matt H is running a VF22 now, but is 82.5mm bore 1800+cc and on 1 bar boost he was flying round combe on saturday. looked really good. his is switchable to 1.6bar also which gave him ~370bhp on Owen's rollers apparently.
VF22 has P20 housing btw
His is running my valves now.
I kinda miss the mk4 having seen it blitz round combe :(
tommo-turbo
04-12-2006, 11:56
Bill
As we discussed I think you suggested running 300hp utilising a VF34 p20 which shouldn't destroy or cause heat issues for my track work.....should be reliable on those settings.
IHI seems a nice progressive delivery looking at various logs. APR stage 3 available only for TT and S3 at present.
What's your oppinion of the eliminator range.....they appear from what I've read is that they are very laggy?
Anyone got any dyno logs on these.
Ian
I thought APR stage 3 was only available for the A4?
Stage 3 for the TT180 & A4, Stage 3+ for TT180, TT225 and A4's. TT's LHD only though, AFAIK. Supposed to be developing a RHD Manifold in Australia, but not heard anything about it for ages.
The question about lag/boost threshold on the GT28 based tubbies is why I was asking. Wondering if it's just the .71 that's laggy?
What would be an objective measure of boost threshold? ISTR reading somewhere about the point in the revs at which a turbo's classed as spooled, is where boost has reached a certain percentace of maximum? Or am I dreaming again?
Has anyone put an IHI on an A4 :whistle: ?
I`m sure that APR St3+ for rhd/fwd will be available shortly - like now??? - Guy in Australia had the manif finished long time ago - i wonder why we`re still waiting:think: :whistle:
As for this BT `turbo lag `issue - in the last analysis it probably comes down to personal preference - some guys will like it other will not!
As i`ve said before, I certainly have no problems with my IHI setup, for use in the course of the normal daily commuter grind - as a matter of fact the car`s 6th gear performance is for me one of its best traits.
On the journey home tonight, in the usual 60/70/80 mph Yo-Yo traffic flow, the car is quite happy to drop to 2.5k in 6th[60 mph/GPS] and pull part/ full throttle without any distress - indeed in the vast majority of circumstances there`s no need whatsoever to drop a gear - the performance available is more than adequate to keep pace with traffic flow
Once the motor hits 3K[72mph/GPS] in 6th on full throttle, it will get to 4k[96mph/GPS] in just over 7sec :D
Koomorph
21-12-2006, 20:08
Bill
Why do you rate the IHIs over the GT28RS? I've seen some excellent results with this turbo pushing into the 350s bhp (not on VAG motors admitadly), but was considering going the eliminator route myself..... thought it was a solid turbo alround.... Would be interested to read your thoughts...
Cheers
Raf
ibizacupra
22-12-2006, 10:40
Bill
Why do you rate the IHIs over the GT28RS? I've seen some excellent results with this turbo pushing into the 350s bhp (not on VAG motors admitadly), but was considering going the eliminator route myself..... thought it was a solid turbo alround.... Would be interested to read your thoughts...
Cheers
Raf
the gt28rs i have driven did produce higher power than then vf34/p20, but in driving terms the spool characteristics of the vf34 were better, faster and far more responsove to on-off-on throttle applications.
A lot of this is down to the low inertia of the VF34 compared to the relative chunky GT series, but its low inertia is from small shafts, small bearings, which when you pump a VF34 up too high, becomes part of their weakness. Oversped bearings can and will fail as several IHI owners (not me surprisingly) have suffered. Keep the boost levels sane on the VF34 and its a great 1.8T complementry package, to which mike truluck @ Jabba has pioneered to great success. Its when we all now want >300bhp and closer to 400bhp (greedy aint we) that the GT series gets more appealing with its greater model option range over IHI. For us in rhd land, its also a big factor of manifold availability too, and its been Jabba's IHI mani or none, unless you go and make your own (like have evolved to)
VF34 is a nice unit for low 300's and its power delivery is nice & smooth, sustained (over k0x units) and very fast.
Its all a compromise... want higher bhp, then accept the inevitable it aint going to spool at 2K like a K03 would, but it can continue pulling hard to 7Krpm unlike a k03 unit.
hope this helps explain.
:thumbup:
Koomorph
22-12-2006, 15:09
Thnaks Bill, appreciate your input. I guess there's also the cost vs bhp factor to consider. The GT eliminators and manifolds from ATP can work out £££ cheaper than going the IHI route - even when you take into account all the peripherals...
What's your take on using stand alone engine management like OMEX for example (although I'm not even sure it's sutiable for VAG engines...) and coupling it with anti-lag......?
Cheers
Raf
Koomorph
11-01-2007, 23:24
And one more thing Bill..... any idea what rpm the crank is rated to on the 1.8T?
Cheers
Raf
ibizacupra
12-01-2007, 21:48
And one more thing Bill..... any idea what rpm the crank is rated to on the 1.8T?
Cheers
Raf
forget antilag for a road car IMHO
OMEX is ok but you need to ditch fbw (I believe)
Mapping stock ecu is'nt an issue if you use the right tuner.
mine 485+bhp now on bog stock ibiza ecu.
Mapped by Custom Code.
no idea on crank absolute limit but there's folks on vortex running 700bhp on stock crank (apparently). mines >500bhp with its new mani on stock crank.
Koomorph
12-01-2007, 22:45
Thank again Bill - here's something that ATP sent me RE rev limit -
"As far as rev limiters go, the 1.8T valvetrain appears to be as reliable as 8000 rpms, so if you're able to keep it right under 7500 rpms, you'll never have a high RPM failure due to over-revving. We've done consistent 8200 rpms on setups where we can risk failure and we've never encountered a problem with the high revs."
Raf
ibizacupra
13-01-2007, 08:19
Thank again Bill - here's something that ATP sent me RE rev limit -
"As far as rev limiters go, the 1.8T valvetrain appears to be as reliable as 8000 rpms, so if you're able to keep it right under 7500 rpms, you'll never have a high RPM failure due to over-revving. We've done consistent 8200 rpms on setups where we can risk failure and we've never encountered a problem with the high revs."
Raf
I dont agree with them on this.
valve failure on my mk4 twice on std valve train on those same rpms would say the opposite, along with several other 20v cars I know of.
Uprated valves @ £375 vs total engine/turbo destruction £4000+
Its a simple equation.
If specing a turbo to "use" these rpms also consider valve springs to suit - £350/engine set, includes Ti retainers for less weight/strength.
my 2 penneth.
Koomorph
14-01-2007, 23:19
Righto - did you have valve failure at 8K rpm, or lower?
Raf
ibizacupra
15-01-2007, 08:56
Righto - did you have valve failure at 8K rpm, or lower?
Raf
lower... but the engine was used to 8k so at some point fatugue set in and failure was random after then.
There is no concidence that all the major UK tuners now use valves first identified and used by myself, where previously they considered std valves ok... up to the point they failed!
If building a BT car, which will have a higher rev ability to pump the air, then omitting valves is a risk I am not prepared to take. The cost vs expence of not doing it is a no brainer. total engine write off, including turbo is the end result when it happens.
£375 vs £4000 to scratch build another engine/turbo
Easy maths.
interested follower of this thread....
ibizacupra
16-01-2007, 08:59
another factor is running them lean :whistle:
traumapat
16-01-2007, 09:11
this thread is frightening! since reading my right foots gotten very nervous:(
though im certain im within acceptable limits (franticly runs around house searching for a piece of wood....)
ibizacupra
16-01-2007, 09:23
log block 30 & 31 and see what afr your running.
might settle your mind (or not)
Koomorph
16-01-2007, 18:02
Poin taken Bill. Thanks for the good advice. If the injectors have enough headroom and aren't being maxed out, there's no reason it should run lean if it's been properly mapped.......?
Traumapat - is your rev limit raised?
Raf
ibizacupra
16-01-2007, 18:23
If the injectors have enough headroom and aren't being maxed out, there's no reason it should run lean if it's been properly mapped.......?
correct... and the latter part of the statement is key.
traumapat
17-01-2007, 07:37
bill... ill get those logs done.
the uprated valves.... 375 fitted?
raf... limited to 7500rpm..
ibizacupra
19-01-2007, 21:21
valves are £375 supplied only inc vat although I can advise on who to fit them for you (head off)
traumapat
19-01-2007, 21:37
valves are £375 supplied only inc vat although I can advise on who to fit them for you (head off)
anything else worth considering other than valves? not planning on taking mine over 320 but who knows...
ibizacupra
19-01-2007, 22:05
springs maybe if you ever consider cams and more revs
head stud conversion maybe if considering more geegee's and higher boost at a later date
traumapat
19-01-2007, 22:38
im proberly going to work with this power level for the life of this engine.. so uprated valves are proberly all i need . ive gotten used to the power now but still learning to use it at its best.
i never intended to mod the leon... in fact ive never modding anything before. retrospect nudges me into wishing id done this to a beeza..if only for the weight advantage... then id proberly aim higher.
mr leons a different car again since the bt convs. the turbos really settled down now and ive lost the torque steer . want to keep it that way.
am i kidding myself thinking £1k to have the valves fitted? roughly?
be a while as i just moved house so the money trees impersonating a shrub atm.
ibizacupra
20-01-2007, 10:08
im proberly going to work with this power level for the life of this engine.. so uprated valves are proberly all i need . ive gotten used to the power now but still learning to use it at its best.
i never intended to mod the leon... in fact ive never modding anything before. retrospect nudges me into wishing id done this to a beeza..if only for the weight advantage... then id proberly aim higher.
mr leons a different car again since the bt convs. the turbos really settled down now and ive lost the torque steer . want to keep it that way.
am i kidding myself thinking £1k to have the valves fitted? roughly?
be a while as i just moved house so the money trees impersonating a shrub atm.
Could prolly be done for that.. if you are serious I can give you the name & number of the guy who can fit these for you.
Leons a better platform for higher power than ibiza. You chose right. You can go for more power now with a GT30 bolt on jobbie onto the rest of your JS bits for 400+bhp (need internals done for peace of mind)
traumapat
20-01-2007, 19:52
Could prolly be done for that.. if you are serious I can give you the name & number of the guy who can fit these for you.
Leons a better platform for higher power than ibiza. You chose right. You can go for more power now with a GT30 bolt on jobbie onto the rest of your JS bits for 400+bhp (need internals done for peace of mind)
yep serious but need to build up funds first mate. ill ring you when ready.
internals .... would that be stronger rods only? or other stuff too? just curious at this stage...(famous last words.....):doh:
ibizacupra
21-01-2007, 18:10
depending on what pin size are on your existing pistons, then rods if 20mm or rods and pistons if not. Std S3 type would be ok.
traumapat
21-01-2007, 19:27
i guess with the right map 400bhp is still quite driveable?
since ihi im using more oil.. in 6 months im below the bottom kink. new turbo eating it whilst its bedded in? i`ll watch to see if its still using lots.
ive had a puff of smoke when starting from hot from ownership which i put down to a valve seal. its no worse since conversion so i dont think its that.
btw if that is the cause will renewing the valves sort that out?
the cars still a daily commuter so 320bhp is ideal for keeping up with mway traffic:D ... but its nice to know that an extra 80bhp isnt miles away..just in case i get bored.
why do you say that the leons a better platform? intresting.
my current lag is fine. turbos very responsive. is the gt30 laggy?
ibizacupra
21-01-2007, 20:36
i guess with the right map 400bhp is still quite driveable?
since ihi im using more oil.. in 6 months im below the bottom kink. new turbo eating it whilst its bedded in? i`ll watch to see if its still using lots.
ive had a puff of smoke when starting from hot from ownership which i put down to a valve seal. its no worse since conversion so i dont think its that.
btw if that is the cause will renewing the valves sort that out?
the cars still a daily commuter so 320bhp is ideal for keeping up with mway traffic:D ... but its nice to know that an extra 80bhp isnt miles away..just in case i get bored.
why do you say that the leons a better platform? intresting.
my current lag is fine. turbos very responsive. is the gt30 laggy?
oil consumption is rings or stem seals perhaps if you had it before and after. mine had more ring blow by (heavy breathing from) when I retired it for the built motor.
The GT30 is going to be a nice performer I think judging by tims ibiza, albeit his is on a better flowing manifold than the cast one.
If doing valves then bargain for guides and new seals at the same time.