View Full Version : NA engines, who's in the know ???
Looking for a contact who knows the NA engine in the Supes. Have various questions that need answering related to the NA, and will have more in the future no doubt.
Could someone step forward that could offer advice/answer questions..........
Why not post them up here Ash?
I have but people dont seem to answer them, I have already asked what torque a standard NA clutch can hold, also we need someone that works on these engines and knows. We have some queries reagrding some of the breathers, and I dont need people guessing, or asuming, I need someone I can ask directly for a eduacted answer, and not to be discussed with no final outcome.........which tends to happen on here ;)
Do you know alot about them then mate :conf:
I think the problem is that theres not many people who actually get their NA tuned as the cost and complexity outweighs changing to a twin turbo.
Its basically a 3l NA engine which is the same as in the Lexus GS300 I believe, so Lexus Owners Club might be a useful port of call.
As its a non-turbo then pretty much all the usual NA tuning applies, flowing the head, improved breathing etc.
Would be interesting to see what you can find out.
JB
Well were really going to town on the NA, so might have some usefull stuff.
Were pretty much going through all the breathing system on teh NA to find out whats needed and whats not (ie, used for cleaner emissions and stuff).
What we did notice is that the NA has a engine water feed onto the throttle body, is this used for frost purposes or other reasons as it seems it could be heating the air intake charge, if its not needed then it may be able to be blanked therefor giving colder air intake temps.
Why don't you have a word with Mandy (Pink Lady) she's got the most modded NA I can think of, she must be able to point you towards garages that have done the work for her.
the NA was also available in the US so they will know whats possible without putting a turbo on it.
JB
Originally posted by Branners
the NA was also available in the US so they will know whats possible without putting a turbo on it.
JB
;)
I have logged on Supraforums under my ID, except I cant do anyting like post or PM, and I cant re-register as the cookies are picking me up. I cant see anyway of contacting the mods to get them to have a look at my account. Branners, whats the best way to sort this.....
Originally posted by Ashley Willis
I have logged on Supraforums under my ID, except I cant do anyting like post or PM, and I cant re-register as the cookies are picking me up. I cant see anyway of contacting the mods to get them to have a look at my account. Branners, whats the best way to sort this.....
2 things, depends how long its been but they did require you to ask for a password reset at one point so get a password reset done and sent out to you. Other thing to check is that you arent blocking cookies from Supraforums as thats what allows people to register on here but not when it keeps asking them to log back in.
If that fails let me know and I will see what I can sort out with them.
JB
Well it seems you can remove the coolant feed through the throttle body to reduce air intake temps, but you then risk loosing the cars ability to cold start, that all depends on how cold it gets where the car is located, for the US and Oz its probably not much of a problem, but I will still run this mod and see what happens in the winter.
I can search now after re-activating my account, but I still cant post, it said something about waiting 24hrs, would that be a similar process that we run on this board, ie, maybe not able to post until some sort of verification from a MOD or someone.....????
hmm, strange, not seen the 24 hours thing before, but yes, its probably waiting for moderator verification.
I think Lust2luv currently has the fastest NA mkiv in the UK, at TOTB1 it was putting in similar times to a stock mkiv UK spec TT. Im sure theres more to come from an NA, just the cost keeps people from doing too much.
JB
Ok, it looks like its waiting for activation, so will just have to hold tight..........;)
Originally posted by Ashley Willis
Well it seems you can remove the coolant feed through the throttle body to reduce air intake temps, but you then risk loosing the cars ability to cold start, that all depends on how cold it gets where the car is located, for the US and Oz its probably not much of a problem, but I will still run this mod and see what happens in the winter.
how about fitting an isolation valve in the feed line? that way when the weather is really cold you can just turn the tap on. or if you really wanted to be flash an in line solenoid wired to a switch in the car
Originally posted by leett
how about fitting an isolation valve in the feed line? that way when the weather is really cold you can just turn the tap on. or if you really wanted to be flash an in line solenoid wired to a switch in the car
mmmmmmm, now we are getting fancy ;) :D
Good idea Lee, I like it........
I like these threads. Lots of juicy info.
Originally posted by Rob
I like these threads. Lots of juicy info.
Sorry, you leave my juicy bits of it thanks :innocent:
Like what juicy info anyway.......:conf:
See Ash,
Getting a few decent pointers now mate. :) Fair play I know wht you mean about wafflein threads when all you want is good technical advice. I do not have a NA but I suppose all standard NA tuning applies here.
Air Intake (cold air feed where possible or shielded from heat as a minmum)
Properly sized free flowing exhaust manifold
Cat removal
Correctly sized exhaust system
Gas flowed cylinder head
Possibly larger valves depending on goals
Close attention to porting around valve throat and seat
Polished combustion chambers
Inlet manifold tidied up (depending on how rough it is internally)
Removal of manifold heating
Camshafts (again depends on outright goals but on a 3litre motor you can afford to go fairly wild without a huge trade off in low speed torque)
Lightened and fully balanced internals, pulley and flywheel assembly
Prorammable ecu (Motec, DTA, or similar)
Has anyone ever ran the NA on throttle bodies, any idea if there's any gains over the plenum chamber setup with its fancy runner length assembly. I would have thought that on anything less than an all out race engine the "stock based" runners and plenum would be sufficient.
Not sure on the safe rev limit of the bottom end, may be worth having a word with CW. I'd imagine no more than 7500 max without turning attention to the rods and bolts at least. I have no idea what sort of revs/power the stock pistons are safe to but this all depends if you're heading towards high rpm tuning.
Big £££'s if that's the case.
Dan
Originally posted by Ashley Willis
What we did notice is that the NA has a engine water feed onto the throttle body, is this used for frost purposes or other reasons as it seems it could be heating the air intake charge, if its not needed then it may be able to be blanked therefor giving colder air intake temps.
100% correct, the NA does have one, and it is a common and easy 'mod' to do. Go for it! It is all on SF, so sign up again and sort out your account, a few seraches on there will bring up all you need. :)
Originally posted by dandan
Not sure on the safe rev limit of the bottom end, may be worth having a word with CW. I'd imagine no more than 7500 max without turning attention to the rods and bolts at least. I have no idea what sort of revs/power the stock pistons are safe to but this all depends if you're heading towards high rpm tuning.
Big £££'s if that's the case.
Dan
Same goes for the top end. You'll probably end up needing different valve springs at least to stop you running into float.
throttle heater removal does make a difference. no problems on mine either
Well it seems you can remove the coolant feed through the throttle body to reduce air intake temps, but you then risk loosing the cars ability to cold start
i was thinking of doing this mod myself .i wonder how cold it needs to be before you get starting probs as we know toyota is good at over engineering and we might not need it in our winters P.M me pls and let me know if you had any probs-- thanks bud
how about fitting an isolation valve in the feed line? that way when the weather is really cold you can just turn the tap on. or if you really wanted to be flash an in line solenoid wired to a switch in the car
what a good idea well done mate wonder where i can get a valve that will fit such a small tube??
Bad idea dont disrupt the flow, if you really want to do this just join the two hoses together to bypass the body
i was thinking of doing this mod myself .i wonder how cold it needs to be before you get starting probs as we know toyota is good at over engineering and we might not need it in our winters P.M me pls and let me know if you had any probs-- thanks bud
Never done it in the end dude, me and the misses split, it was hers and then it was written off a few months later anyway.... ;)
Cant beleive this thread has been re-dug up, 2004 as well...... :d
it was at the top of the pile but i forgot i was using search lol
I thought the water feed to the throttle body was to stop it icing up in real cold weather. You think about how cold the air must be when rushing past at x metres per second if it's -5degC ambient - add some moisture and it could freeze the throttle open. Which would be bad.
Helps cold start, that's funny that is :) How exactly does it do that eh? By supplying heat? Er, the coolant is cold, that's why it's a cold start :D
-Ian
Lucifer has done an n/a with 350bhp and no turbo, thread on mkiv store section somewhere
Lucifer has done an n/a with 350bhp and no turbo, thread on mkiv store section somewhere
Is doing not done. It let go big time.
Current figure is around 300. A customer has one of ours on a proven 251@7000
Is doing not done. It let go big time.
Us vultures demand photos of nasty broken bits! What happened? Which bit let go? My money is conrod at high rpms :)
-Ian
Ian why do you say the conrod, I have just this dicussion with someone and they say the internals are exactly the same as the TT lump, only difference being the oil squirters ??
The internals are the same...
If the rev limit was raised really high, it would snap a rod on either engines...
Ian why do you say the conrod, I have just this dicussion with someone and they say the internals are exactly the same as the TT lump, only difference being the oil squirters ??
High RPMs is the only real way of getting big power out of an NA engine, and high RPMs put a massive load on the conrod at TDC on the exhaust stroke, and it's a tensile force, i.e. it's pulling the big end apart.
A TT would fall apart the same way, only they don't have to be revved to buggery to get power :)
-Ian
Chris Wilson
26-09-06, 00:17
I thought the water feed to the throttle body was to stop it icing up in real cold weather. You think about how cold the air must be when rushing past at x metres per second if it's -5degC ambient - add some moisture and it could freeze the throttle open. Which would be bad.
Helps cold start, that's funny that is :) How exactly does it do that eh? By supplying heat? Er, the coolant is cold, that's why it's a cold start :D
-Ian
Thank you Ian, a voice of sanity speaks out from the melee.
Us vultures demand photos of nasty broken bits! What happened? Which bit let go? My money is conrod at high rpms :)
-Ian
Not far off Ian, No 1 big end Bearing, we used Toyota bearings, its now being rebuilt with Clevite 77.
I usually use Clevite, but this was our first Na so it was a bit of a test of the OE parts too really.
Oh and it let go at around 9100 rpm. We were hoping for 10k.
Not far off Ian, No 1 big end Bearing, we used Toyota bearings, its now being rebuilt with Clevite 77.
I usually use Clevite, but this was our first Na so it was a bit of a test of the OE parts too really.
Now I'm not *that* up on engine internals so I'm interested in this - I thought that the bearing surfaces weren't supposed to touch metal-to-metal at all, and there is a oil bearing surface between them. The phrase "spun up a bearing" or "picked up a bearing" means, as far as I know, that the conrod has touched the crank while under load and speed, due to low oil pressure or oil starvation or something (overrevving!), and the bearing surface gets mashed up. So if that's correct - how does changing the bearing type make a difference when it comes to high rpms? If they touch it's lunched no matter what it is, it's just supposed to be smooth and nicely within tolerance to provide the perfect surface for the oil...?
I'm gonna poach this thread for tech :)
-Ian
Jason who builds the engines here (Ex WRC engine builder for Toyota) is out today so ill get the info tomorrow. Its over my head when we get this far into engines. He did explain about crank whip, but I gto a bit lost.
A take it the next attempt will be using a dry sump setup then Martin?
9100rpms is pretty good going though :D
supracar1995na
27-09-06, 02:36
Good luck on getting permission to post on that site.I signed up days ago,and have since sent them e-mails and still NOTHING,not even a reply.I figure ....They wanna be that way,guess I don't need em.I go to all the other forums and have gotten advice from some great ,friendly people without having to WAIT to be included.Though my post on here hasn't gotten ANY replies,and I have a mystifying problem,so far it sounds like I'm gonna have to start cuttin wires in the dash.
Errr I think you posted that in the wrong thread?
-Ian
Now I'm not *that* up on engine internals so I'm interested in this - I thought that the bearing surfaces weren't supposed to touch metal-to-metal at all, and there is a oil bearing surface between them. The phrase "spun up a bearing" or "picked up a bearing" means, as far as I know, that the conrod has touched the crank while under load and speed, due to low oil pressure or oil starvation or something (overrevving!), and the bearing surface gets mashed up. So if that's correct - how does changing the bearing type make a difference when it comes to high rpms? If they touch it's lunched no matter what it is, it's just supposed to be smooth and nicely within tolerance to provide the perfect surface for the oil...?
I'm gonna poach this thread for tech :)
-Ian
Possibly a larger bearing standout? So that the clamp load on the bearing is much higher, and would presumably keep the bearing from spinning if the big end started to separate slightly.
Errr I think you posted that in the wrong thread?
-Ian
I presume he was on about Supraforums mentioned on the first page.
Thank you Ian, a voice of sanity speaks out from the melee.
I thought the water feed to the throttle body was to stop it icing up in real cold weather. You think about how cold the air must be when rushing past at x metres per second if it's -5degC ambient - add some moisture and it could freeze the throttle open. Which would be bad.
Helps cold start, that's funny that is :) How exactly does it do that eh? By supplying heat? Er, the coolant is cold, that's why it's a cold start :D
-Ian
So, is there a general consensus about this mod? It sounds like it could be worthwhile for summer to autumn times.
So, is there a general consensus about this mod? It sounds like it could be worthwhile for summer to autumn times.
a know of 4 celica owners who have done this mod and ran through winters without a glitch
Well like Ian or someone rightly pointed out :blink: whats the point in having the hose feed through your throttle body for cold winter starts when the water would be cold in the first place from you only just starting it, so what is the point of that design.....
Now I'm not *that* up on engine internals so I'm interested in this - I thought that the bearing surfaces weren't supposed to touch metal-to-metal at all, and there is a oil bearing surface between them. The phrase "spun up a bearing" or "picked up a bearing" means, as far as I know, that the conrod has touched the crank while under load and speed, due to low oil pressure or oil starvation or something (overrevving!), and the bearing surface gets mashed up. So if that's correct - how does changing the bearing type make a difference when it comes to high rpms? If they touch it's lunched no matter what it is, it's just supposed to be smooth and nicely within tolerance to provide the perfect surface for the oil...?
I'm gonna poach this thread for tech :)
-Ian
Right just spoke to Jason and he said the reason was due to the Rod oil exit clearences. He is re machining an NA crank for more clearence this week.
Basiacally the bearing could stand up to the heat which is why we are going clevite and widning the oil ways.
Widning the oilways is what we do to the big single engines too as a matter of course.
Well like Ian or someone rightly pointed out :blink: whats the point in having the hose feed through your throttle body for cold winter starts when the water would be cold in the first place from you only just starting it, so what is the point of that design.....
I have had inlet icing in Spring too. I woudl never remove that system on teh stock system. Bad idea.
I dont doubt you mate, just saying like Ian or someone pointed out.......... ;)
Right just spoke to Jason and he said the reason was due to the Rod oil exit clearences. He is re machining an NA crank for more clearence this week.
Basiacally the bearing could stand up to the heat which is why we are going clevite and widning the oil ways.
Widning the oilways is what we do to the big single engines too as a matter of course.
Do you mean the big end bearing clearance?
Do you mean the big end bearing clearance?
NO he was talking about the Rod clearences to the Crank, ie the width. ILl try and get him on here if you like. he doesnt do computers though so maybe ill just record the conversation and retype it! LOL
I dont doubt you mate, just saying like Ian or someone pointed out.......... ;)
I think you've interpreted it wrong - it's there to stop the throttle icing up during driving, i.e. when the coolant is hot. The whole thing about cold start was a red herring, it's not a design feature for cold starts.
-Ian
I think you've interpreted it wrong - it's there to stop the throttle icing up during driving, i.e. when the coolant is hot. The whole thing about cold start was a red herring, it's not a design feature for cold starts.
-Ian
I know, thats why I asked what is for then a few posts back after you quite rightly pointed how it cant be for cold start when the water would be cold from start..........read things properly Ian....lol :p
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