tuning for a 58mm tb

I have looked around and can't find anything on how to tune the car for a 58mm tb. Are you just looking at the maf tables to adjust do you add more timming/fuel for tip in, what about daily driving

am i asking everthing here for this ?

thx

There is no tuning required for a 58 MM Throttle body. What exactly is your problem ? I have a 383 stroker LT1 and started with a bad tune but it has come a long ways. If you are getting a stumble on throttle tip in you need to increase your spark advance and decrease your fuel a little. IF your using LT1 edit send me your LT1 file and give me a description of whats wrong. I like to tune stuff:D

I've heard before that you have to mess with the shift points on an A4, but I've never heard an explanation of why.
Anyone?

i heard the same thing, however I didnt have to change anything with my shift points. I have the BBK 58MM throttle body. Maybe different throttle bodies need to have the shift points changed?
I really dont see any reason to have to change shift points. Only the older L98 cars used the throttle body blade position to manually chose a shift point. LT1s use the TPS sensor, I did need to adjust my TPS sensor voltage with the new throttle body.

O.k i am a heads and cam car M6 just looking into what mods to do this winter i have a 52mm tb now was thinking of uping to 58mm

Hum? i have done some reading and they say that the maf will not adjust for the bigger TB, over on advance they did a big talk about TB size and they said you have to tune in , i will see if i can find it?

Here it is

HP and TQ gains have been proven many times over with the larger TB.

Large TBs make tip in brutal at times but I am working on a throttle cam to ease this problem. for those who can not wait TPIS has a new TB with new design.

I can count how many times I have had to stop and explain to people that you can not go to big on the TB with a port injected car. There is no need for High velocity over any of the sensers. There is no ventury velocity needed like in a carb to get the right mixture.

As long as you have correctly tuned your car you will benifit from the TB. Your TB is more of a restriction then your MAF and everyone on earth seems to be hacking the hell out of those LOL

Chris Bennit(sp), Jordon Musser and my self have all show VERY measurable gains with larger TBs.

As long as you have correctly tuned your car you will benifit from the TB. So just as lonfg your tune is good youre ok
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No tuning for an M6 needed. Maybe zero out the burst knock if you didn't already do it. My car used to pick up more burst knock after the TB.

A4s most of the time shift weak and soft after a bigger TB install. Adjustments to line pressure will fix that.

What is burst knock ie: like tip in knock and where would you adjust it to? or how much.

How do you know so much :confused: madwolf:bow: about tuning cars

Most commonly, you will see burst knock immediately after a gear shift on a 6 speed. (when you're shifting quick)
Or if you're cruising along at like 60 mph 10% TPS and then suddenly go WOT (100%)
Basically burst knock will kick in when there's a sudden, large increase in manifold absolute pressure. So I guess the logical explanation why my M6 was getting more burst KR after the TB is because there was simply more air rushing in.

Oh yes, I forgot to mention that for A4s, fixing the pressure tables of the TB is very important, or else you're risking a premature failure. Installing a 58MM TB and not adjusting the pressure feels and it's just as bad as driving around with slack in the TV cable on a 700R4 or any other non electrical auto.

Thx madwolf:thumb:

Ion,
What is actually different on the larger tb's that makes line pressure adjustments necessary?
See if you can follow me here...
With the larger throttle body you can ingest a larger amount of air at the same TPS% than with the smaller throttle body due to the larger blade diameter. So then wouldn't it make sense that if you're at a lower TPS % getting the same amount of air, that the line pressure would be slightly higher than what it was before the tb swap?
I guess I just don't understand why any change would be necessary at all.

Well I definatly needed a 58 MM throttle body. I put down 431 RWHP without nitrous. I also have a HUGE solid roller camed 383 LT1 runnign very high compression. I already adjusted my transmission to shift firmer than stock because it felt sluggish. Now I know the 58 mm throttle body did it.

However your talk of Burst knock has intruiged me. Was is only a known issue on M6 cars or did you just notice it on YOUR car that happened to be an M6. I have an A4 and sometimes my car seems to feel weeker than usual when crusing then going full throttle. It doesnt happen always, just sometimes. Would you recomend disabling burst knock, or jsut chopping hte current amount in half ? I am using an LT4 KM and I run true 3 inch dual with Xpipe. I NEVER get knock retard that I can see and I run anywhere from 35-41 degrees of timing in my timing tables.

It's hard to imagine that neither TC or LT1 Edit has found the acceleration enrichment (pump shot) tables in the code. There should be an AE vs Delta TPS table and an AE vs Delta MAP table. GM has used these tables since Moses was a baby! Those tables gotta be in there. This is what we really need to solve those nasty tip in problems.

I don't know if I can explain this correctly, but I'll try.

The trasmission works according to the TPS % value reported by the throttle position sensor. You can put a monoblade in there, but the sensor will still report the same angles. (however the volume of air for the same angle will now be bigger, which means more RPM)

So for instance you have a monoblade. You very slightly touched the accelerator pedal and your engine will probably be reving at 1500 already (example). The TPS will still be like 5% but the engine will actually be running at more rpm than it would run at 5% with a stock TB. (let's say the same RPM for 5% for a stock TB would've been 750) so the tranny will shift like it's shifting for 750 RPM...

Sorry if I'm not explaining well enough. I understand how this works, but I guess I'm not too good with transforming it into words. ;)

That makes sense. It's just opposite of what I was thinking.
The fact that more air in with the bigger tb resulting in more rpm wasn't clear in my head.
But with a bigger tb=more rpm at the same tps then you would have lower line pressure at a higher rpm than you did before the tb swap.
Thanks! :)

This may not be the place but, Ion & Dan with all the tuning that you have done can you put on a TB to big and hurt performance or is like i posted above as long as the car is tuned youre fine

thx this is great info it was not out there before nor i could not find it :confused:

Yes, you can hurt performance if you put a (significantly) bigger TB than needed. The car will tend to bog down whenever you try to go WOT.

There's a formula here somewhere for figuring out how much air your engine needs and how much various TBs will flow.

Schurters LT1, you should check out www.kwfbody.com if you haven't already since your from KW.

johnny o,
thx